HomeMy WebLinkAboutFile Documents.395 Thunderbowl Ln.0153.2017 (24).ARBKGrading and Drainage Report
Prepared for
David Johnson Architects
395 Thunderbowl Lane, aspen
P.O. Box 575
Woody Creek, Colorado 81656
970-309-7130
Prepared By
Josh Rice, P.E.
July, 05 2017
Revised January, 11 2018
1/16/18
Reviewed by Engineering
04/25/2018 6:25:09 PM
"It should be known that this review shall not
relieve the applicant of their responsibility to
comply with the requirements of the City of
Aspen. The review and approval by the City is
offered only to assist the applicant's
understanding of the applicable Engineering
requirements." The issuance of a permit based
on construction documents and other data shall
not prevent the City of Aspen from requiring the
correction of errors in the construction
documents and other data.
i
I hereby affirm that this report and the accompanying plans for the drainage improvements of Lot 7 Block
A, The Aspen Highlands Willage P.U.D. was prepared by me for the owners thereof in accordance with the
provisions of the City of Aspen Urban Runoff Management Plan and approved variances and exceptions
listed herein. I understand that it is the policy of the City that the City of Aspen does not and will not
assume liability for drainage facilities designed by others.
Josh Rice, P.E. License No.
1/11/2018
1/16/18
ii
1. INTRODUCTION ................................................................................................................................. 1
2. GENERAL SITE DESCRIPTION ....................................................................................................... 1
2.1 Existing Condition ..................................................................................................................................... 1
2.2 Proposed Condition ................................................................................................................................... 2
2.2.1 Determination of Major/Minor .................................................................................................................... 2
2.3 Drainage Basins ......................................................................................................................................... 2
2.3.1 Historical Basin EB : 1 ................................................................................................................................... 5
2.3.1 Proposed Basin ............................................................................................................................................. 5
3. STORMWATER BMPS AND ROUTING ......................................................................................... 5
3.1 General ..................................................................................................................................................... 6
3.1.1 Detention Calculation .................................................................................................................................. 6
3.1.2 Outlet Calculation ........................................................................................................................................ 6
3.2 Pipe Calculations ....................................................................................................................................... 7
3.2.1 Pipe A ........................................................................................................................................................... 7
3.2.2 Pipe B ........................................................................................................................................................... 7
3.3 Inlet Calculations ....................................................................................................................................... 7
3.3.1 Operation and maintenance ........................................................................................................................ 8
APPENDIX A--NRCS SOILS REPORT ................................................................................................. 1
APPENDIX B--FEMA FIRM MAP ......................................................................................................... 2
APPENDIX C--PLAN SET ....................................................................................................................... 3
APPENDIX D--HYDROLOGIC CALCULATIONS ............................................................................... 4
APPENDIX E--HYDRAULIC CALCULATIONS .................................................................................. 5
APPENDIX F—DETENTION CALCULATIONS ................................................................................. 6
1/16/18
1. Introduction
This report was prepared to meet the requirements of a City of Aspen Engineering Department Grading and
Drainage Report for a Major Design. The report was prepared for a single-family housing project at 395
Thunderbowl Ln, Aspen, Colorado, 81611 (the “Site”). Facilities providing water quality capture volume
and detention have been designed in this report and the associated plan.
2. General Site Description
2.1 Existing Condition
The property was platted as Lot 7 Block A, The Aspen Highlands Willage P.U.D. Based on the topograph-
ical improvement survey, the lot area is approximately 30,198 square feet.
The Site is located near the Aspen Highlands Ski Resort (see Figure 1). The soils are described by the
NRCS as, “Yeljack-Callings complex, 12 to 25 percent slopes” (see Appendix A). The hydrologic soil
group is “C.” The lot is currently vacant.
Figure 1. 395 Thunderbowl Ln, Aspen Vicinity Map
(Source: maps.google.com)
The site is located well away from all major drainage ways and is not located within the floodplain bound-
aries the Maroon Creek. The Site is located within Zone X, as shown and described by FEMA (see FIRM
Map, Appendix B.)
1/16/18
2
2.2 Proposed Condition
A new single-family structure will be constructed on the vacant lot. The existing building will be demol-
ished.
2.2.1 Determination of Major/Minor
The Urban Runoff Management Plan (the “URMP”) has two controlling triggers when determining the
permit requirements: interior demolition and exterior disturbed area. Based on these two triggers, Woody
Creek Engineering (“WCE”) has determined that water quality capture volume (“WQCV”) and detention
is required for the entire property.
The Site is located on a hill that slopes to the North at 12%. Drainage basins are delineated on Plan Sheet
C.1 (Appendix C, C.1). The basins are described in the following sections. The drainage issues and WQCV
treatment BMPs are also described.
2.3 Drainage Basins
Both Historical and proposed basins are described below. Table 1, below, describes the impervious area,
pervious area, total area, percent imperviousness, flow path length, basin slope, runoff coefficients for the
minor (5-yr) and major (100-yr) storm events and runoff flowrates for the minor (5-yr) and major (100-yr)
storm events. Although the Basins are delineated on Plan Sheet C.1 (Appendix C, C.1), they are also
provided in Figure No. 2 and 3, below.
Historical peak flows for the 5-year and 100-year events were evaluated for the Site using a time of con-
centration based on the flow path length and slope.
Table 1. Basin Information
BASIN NO.
TOTAL BASIN
AREA (ACRES)
IMPERVIOUS
AREA (ACRES)
%
IMPERVIOUS
RUNOFF COEF.
5YR
RUNOFF COEF.
100YR
FLOW PATH
LENGTH (FT)
FLOW PATH
SLOPE (FT/FT)
PEAK FLOW
5YR (CFS)
PEAK FLOW
100YR (CFS)
PB:1.0 0.203 0.023 0.11 0.22 0.53 156.00 0.10 0.111 0.526
PB:2 0.025 0.000 0.00 0.15 0.50 5.00 0.50 0.012 0.079
PB:3 0.004 0.004 1.00 0.90 0.96 5.00 0.50 0.012 0.024
PB:4 0.010 0.000 0.00 0.15 0.50 5.00 0.50 0.005 0.033
PB:5 0.028 0.028 1.00 0.90 0.96 5.00 0.50 0.083 0.169
PB:6 0.001 0.001 1.00 0.90 0.96 5.00 0.50 0.003 0.008
PB:7 0.012 0.000 0.00 0.15 0.50 5.00 0.50 0.006 0.037
PB:8 0.004 0.004 1.00 0.90 0.96 5.00 0.50 0.010 0.021
PB:9 0.017 0.003 0.20 0.26 0.55 5.00 0.50 0.014 0.010
PB:10 0.007 0.007 1.00 0.90 0.96 5.00 0.50 0.021 0.042
PB:11 0.002 0.002 1.00 0.90 0.96 5.00 0.50 0.006 0.012
PB:12 0.010 0.008 0.82 0.64 0.76 5.00 0.50 0.022 0.383
PB:13 0.015 0.015 0.00 0.15 0.50 5.00 0.50 0.007 0.047
PB:1.1 0.087 0.003 0.03 0.17 0.51 113.00 0.14 0.042 0.240
PB:1.2 0.033 0.002 0.05 0.18 0.52 63.00 0.16 0.020 0.106
PB:1.3 0.009 0.000 0.00 0.15 0.50 31.00 0.19 0.004 0.028
PB:1.4 0.017 0.000 0.02 0.16 0.51 46.00 0.22 0.009 0.055
PB:1.5 0.031 0.015 0.50 0.40 0.60 39.00 0.01 0.034 0.098
PB:1.6 0.046 0.046 1.00 0.90 0.96 10.00 0.02 0.136 0.278
PB:1.7 0.011 0.000 0.04 0.15 0.50 25.00 0.36 0.005 0.035
PB:1.8 0.016 0.016 1.00 0.90 0.96 42.00 0.08 0.047 0.097
PB:1.9 0.105 0.007 0.07 0.19 0.52 92.00 0.07 0.053 0.281
1/16/18
3
Figure 2. Historical Basins
1/16/18
4
Figure 3. Proposed Basins
1/16/18
5
2.3.1 Historical Basin EB : 1
Historical Basin EB : 1 slopes to the north at 10% and encompasses the entire lot, as shown in Figure 2.
The basin developed a historical 100-yr flowrate of 1.485 cfs. Refer to Appendix D for additional infor-
mation.
2.3.1 Proposed Basin
The flowpaths of the proposed basins are described in Table 1. Basin Information and Table 2. Basin
Routing.
Table 2. Basin Routing
3. Stormwater BMPs and Routing
Low impact design has been utilized where possible to provide WQCV and detention.
9 Principles
1. Consider stormwater quality needs early in the design process.
The architect and owner considered stormwater requirements early in the process.
2. Use the entire site when planning for stormwater quality treatment.
Where possible, overland conveyance was utilized to increase the time stromwater is in contact
with natural systems.
3. Avoid unnecessary impervious areas.
SUB-Basin
ID Path 1 Path 2 Path 3 Path 4 Path 5 Path 6 Path 7
Final
Basin ID WQ BMP ID
PB:1.0 Sheet Flow Rain Garden PB:1.0 Rain Garden
PB:1.1 Inlet 5 Pipe B Rain Garden PB:1.0 Rain Garden
PB:1.2 Inlet 1 Pipe A Rain Garden PB:1.0 Rain Garden
PB:1.3 Inlet 2 Pipe A Rain Garden PB:1.0 Rain Garden
PB:1.4 Inlet 3 Pipe A Rain Garden PB:1.0 Rain Garden
PB:1.5 Inlet 7 Pipe B Rain Garden PB:1.0 Rain Garden
PB:1.6 Inlet 6 Pipe B Rain Garden PB:1.0 Rain Garden
PB:1.7 Inlet 4 Pipe A Rain Garden PB:1.0 Rain Garden
PB:1.8 Inlet 6 Pipe B Rain Garden PB:1.0 Rain Garden
PB:2 Roof Drain 8 Inlet 8 Pipe B Rain Garden PB:1.0 Rain Garden
PB:3 Roof Drain 7 Driveway Trench Drain Pipe B Rain Garden PB:1.0 Rain Garden
PB:4 PB:2 Roof Drain 8 Inlet 8 Pipe B Rain Garden PB:1.0 Rain Garden
PB:5 (50%)DS 1 Inlet 10 Pipe D Pipe A Rain Garden PB:1.0 Rain Garden
PB:5 (50%)DS 2 Inlet 9 Pipe C Pipe B Rain Garden PB:1.0 Rain Garden
PB:6 Roof Drain 1 Inlet 10 Pipe D Pipe A Rain Garden PB:1.0 Rain Garden
PB:7 PB:9 PB:5 DS 1 Inlet 10 Pipe D Pipe A Rain Garden PB:1.0 Rain Garden
PB:8 Roof Drain 2 Lambs Tongue 1 Inlet 4 Pipe A Rain Garden PB:1.0 Rain Garden
PB:9 Roof Drain 3 Lambs Tongue 1 Inlet 4 Pipe A Rain Garden PB:1.0 Rain Garden
PB:10 Roof Drain 6 Driveway Trench Drain Pipe B Rain Garden PB:1.0 Rain Garden
PB:11 Roof Drain 9,10 Inlet 8 Pipe B Rain Garden PB:1.0 Rain Garden
PB:12 Roof Drain 4,5 Driveway Trench Drain Pipe B Rain Garden PB:1.0 Rain Garden
PB:13 Roof Drain 11 Driveway Trench Drain Pipe B Rain Garden PB:1.0 Rain Garden
1/16/18
6
Impervious areas were reduced where acceptable to the owner and the design team.
4. Reduce runoff rates and volumes to more closely match natural conditions.
The proposed peak runoff rates are no greater than historical runoff rates. The historical flow
paths are followed.
5. Integrate stormwater quality management and flood control.
Through the use of onsite BMPs, stormwater quality management and flood control are integrated
in the project.
6. Develop stormwater quality facilities that enhance the site, the community and the environment.
The site, community and the environment are enhanced by reducing the amount of sediment and
other river pollutants conveyed to the stream system. Hopefully, the use of these stormwater
BMPs on this property and throughout the community will improve the water quality of the Roar-
ing Fork River and its tributaries.
7. Use a treatment train approach.
A treatment train approach is not appropriate for this site.
8. Design sustainable facilities that can be safely maintained.
The stormwater BMPs located onsite can be easily and safely maintained and are readily accessi-
ble.
9. Design and maintain facilities with public safely in mind.
Elevation drops to stormwater BMPs are minimal and designed with public safely in mind.
3.1 General
Low impact design has been utilized where possible to provide WQCV and detention. Basin Routing is
described in Table 2, above.
3.1.1 Detention Calculation
To calculate water quality requirements, WCE calculated the total area of the basins, the impervious area
of the basins, and time of concentration of the basins. Overall, the basins total area equals 0.693 acres,
while the impervious area equals 0.212. The time of concentration for existing basins was found to be
11.27 minutes.
Based on an overall imperviousness of 27% percent, the WQCV in watershed inches is 0.06 in (see Ap-
pendix D). In terms of volume, the WQCV over the tributary area of 0.693 acres is 151 cf (0.06 ac X
43560 sf/ac X 0.065 in X 1 ft / 12 in). The proposed grading of the site, as well as pipe networks, route
runoff into the rain garden along the north end of the lot. This area provides 484.8 cf of detention ((10ft X
2ft /2)X 48.48ft), which is adequate for the detention required for the 100 year storm (425 cf).
3.1.2 Outlet Calculation
In order to drain the 484.8 cf of detention a weir will be placed on the north end of the detention area. The
weir will allow for detained water to be released at the historical 100-year storm rate of 1.518 cfs. Thus,
the weir will have a bottom length of 0.295 ft to allow for a flow of 1.507 cfs at a head of 1.33 ft. In addi-
tion, the outflow velocity will be 2.51 ft/s. For more information, refer to Appendix D.
1/16/18
7
3.2 Pipe Calculations
Two pipes will be installed in order to route runoff to the Rain Garden. Each pipe is described below.
3.2.1 Pipe A
Pipe A captures runoff from Inlets 1, 2, 3, 4, and DS Connect 1. Inlets 1-4 drain directly to Pipe A, DS
Connect 1 transports roof runoff to Pipe A. Inlet 1 collects a flow of 0.028 cfs, which is discharged to a 6-
in PVC pipe set at 4%. This pipe section has a capacity of 1.188 cfs. Inlets 2 and 3 collect another 0.055
cfs for a total flow of 0.083 cfs. This is fed into another section of 6-in PVC pipe laid at 4%, with a flow
capacity of 1.188 cfs. Inlet 4 collects 0.056 cfs for a total of 0.139 cfs, which is carried by a 6-in PVC
pipe at 4%. DS Connect 1 collects 0.055 cfs for a total of 0.194 cfs, which is carried by a 6-in PVC pipe
set at 0.76%, with a resulting flow capacity of 0.518 cfs. Pipe A discharges to a Scour Stop mat at 2.76
ft/s before flowing via swale into the bottom of the Rain Garden. See Appendix E for Pipe calculations.
3.2.2 Pipe B
Pipe B captures runoff from the driveway Trench Drain, Inlets 5 and 6, and DS Connect 2. The Trench
Drain, and Inlets 5 and 6 drain directly to Pipe B, while DS Connect 2 transports roof runoff to Pipe B.
The Trench Drain collects the majority of on-site flows totaling 1.217 cfs before discharging to a 10-in
PVC pipes laid at 0.49%. Pipe B is laid at 0.49% for its entire length. It has a flow capacity of 1.623 cfs.
Inlets 5 and 6 cfs collect aother 0.11 cfs of runoff for a total of 1.327. DS Connect 2 collects 0.112 cfs,
for a total flow of 1.439 cfs. Pipe B discharges to a Scour Stop mat at 3.38 ft/s before flowing into the
bottom of the Rain Garden. See Appendix E for Pipe calculations.
3.3 Inlet Calculations
Six inlets and one trench drain will be installed in order to route runoff to the Rain Garden. Each inlet or
trench drain provide capacity for the tributary 100-year runoff rate with a factor of safety of 2.0. A sum-
mary has been provided in Table 3.
Table 3. Inlet Properties
1/16/18
8
3.3.1 Operation and maintenance
Table 4. presents the recommended maintenance procedures for rain gardens as found in Table 8.12 of
the URMP.
Table 4. Maintenance recommendations (URMP Table 8.12)
1/16/18
Appendix A--NRCS Soils Report
1/16/18
United States
Department of
Agriculture
A product of the National
Cooperative Soil Survey,
a joint effort of the United
States Department of
Agriculture and other
Federal agencies, State
agencies including the
Agricultural Experiment
Stations, and local
participants
Custom Soil Resource
Report for
Aspen-Gypsum Area,
Colorado, Parts of Eagle,
Garfield, and Pitkin
Counties
Natural
Resources
Conservation
Service
June 20, 2017
1/16/18
Preface
Soil surveys contain information that affects land use planning in survey areas.
They highlight soil limitations that affect various land uses and provide information
about the properties of the soils in the survey areas. Soil surveys are designed for
many different users, including farmers, ranchers, foresters, agronomists, urban
planners, community officials, engineers, developers, builders, and home buyers.
Also, conservationists, teachers, students, and specialists in recreation, waste
disposal, and pollution control can use the surveys to help them understand,
protect, or enhance the environment.
Various land use regulations of Federal, State, and local governments may impose
special restrictions on land use or land treatment. Soil surveys identify soil
properties that are used in making various land use or land treatment decisions.
The information is intended to help the land users identify and reduce the effects of
soil limitations on various land uses. The landowner or user is responsible for
identifying and complying with existing laws and regulations.
Although soil survey information can be used for general farm, local, and wider area
planning, onsite investigation is needed to supplement this information in some
cases. Examples include soil quality assessments (http://www.nrcs.usda.gov/wps/
portal/nrcs/main/soils/health/) and certain conservation and engineering
applications. For more detailed information, contact your local USDA Service Center
(https://offices.sc.egov.usda.gov/locator/app?agency=nrcs) or your NRCS State Soil
Scientist (http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/contactus/?
cid=nrcs142p2_053951).
Great differences in soil properties can occur within short distances. Some soils are
seasonally wet or subject to flooding. Some are too unstable to be used as a
foundation for buildings or roads. Clayey or wet soils are poorly suited to use as
septic tank absorption fields. A high water table makes a soil poorly suited to
basements or underground installations.
The National Cooperative Soil Survey is a joint effort of the United States
Department of Agriculture and other Federal agencies, State agencies including the
Agricultural Experiment Stations, and local agencies. The Natural Resources
Conservation Service (NRCS) has leadership for the Federal part of the National
Cooperative Soil Survey.
Information about soils is updated periodically. Updated information is available
through the NRCS Web Soil Survey, the site for official soil survey information.
The U.S. Department of Agriculture (USDA) prohibits discrimination in all its
programs and activities on the basis of race, color, national origin, age, disability,
and where applicable, sex, marital status, familial status, parental status, religion,
sexual orientation, genetic information, political beliefs, reprisal, or because all or a
part of an individual's income is derived from any public assistance program. (Not
all prohibited bases apply to all programs.) Persons with disabilities who require
2
1/16/18
alternative means for communication of program information (Braille, large print,
audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice
and TDD). To file a complaint of discrimination, write to USDA, Director, Office of
Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or
call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity
provider and employer.
3
1/16/18
Contents
Preface....................................................................................................................2
How Soil Surveys Are Made..................................................................................5
Soil Map.................................................................................................................. 8
Soil Map................................................................................................................9
Legend................................................................................................................10
Map Unit Legend................................................................................................12
Map Unit Descriptions........................................................................................ 12
Aspen-Gypsum Area, Colorado, Parts of Eagle, Garfield, and Pitkin
Counties................................................................................................... 14
14—Callings-Yeljack complex, 25 to 65 percent slopes..............................14
117—Yeljack-Callings complex, 12 to 25 percent slopes............................15
References............................................................................................................18
4
1/16/18
How Soil Surveys Are Made
Soil surveys are made to provide information about the soils and miscellaneous
areas in a specific area. They include a description of the soils and miscellaneous
areas and their location on the landscape and tables that show soil properties and
limitations affecting various uses. Soil scientists observed the steepness, length,
and shape of the slopes; the general pattern of drainage; the kinds of crops and
native plants; and the kinds of bedrock. They observed and described many soil
profiles. A soil profile is the sequence of natural layers, or horizons, in a soil. The
profile extends from the surface down into the unconsolidated material in which the
soil formed or from the surface down to bedrock. The unconsolidated material is
devoid of roots and other living organisms and has not been changed by other
biological activity.
Currently, soils are mapped according to the boundaries of major land resource
areas (MLRAs). MLRAs are geographically associated land resource units that
share common characteristics related to physiography, geology, climate, water
resources, soils, biological resources, and land uses (USDA, 2006). Soil survey
areas typically consist of parts of one or more MLRA.
The soils and miscellaneous areas in a survey area occur in an orderly pattern that
is related to the geology, landforms, relief, climate, and natural vegetation of the
area. Each kind of soil and miscellaneous area is associated with a particular kind
of landform or with a segment of the landform. By observing the soils and
miscellaneous areas in the survey area and relating their position to specific
segments of the landform, a soil scientist develops a concept, or model, of how they
were formed. Thus, during mapping, this model enables the soil scientist to predict
with a considerable degree of accuracy the kind of soil or miscellaneous area at a
specific location on the landscape.
Commonly, individual soils on the landscape merge into one another as their
characteristics gradually change. To construct an accurate soil map, however, soil
scientists must determine the boundaries between the soils. They can observe only
a limited number of soil profiles. Nevertheless, these observations, supplemented
by an understanding of the soil-vegetation-landscape relationship, are sufficient to
verify predictions of the kinds of soil in an area and to determine the boundaries.
Soil scientists recorded the characteristics of the soil profiles that they studied. They
noted soil color, texture, size and shape of soil aggregates, kind and amount of rock
fragments, distribution of plant roots, reaction, and other features that enable them
to identify soils. After describing the soils in the survey area and determining their
properties, the soil scientists assigned the soils to taxonomic classes (units).
Taxonomic classes are concepts. Each taxonomic class has a set of soil
characteristics with precisely defined limits. The classes are used as a basis for
comparison to classify soils systematically. Soil taxonomy, the system of taxonomic
classification used in the United States, is based mainly on the kind and character
of soil properties and the arrangement of horizons within the profile. After the soil
5
1/16/18
scientists classified and named the soils in the survey area, they compared the
individual soils with similar soils in the same taxonomic class in other areas so that
they could confirm data and assemble additional data based on experience and
research.
The objective of soil mapping is not to delineate pure map unit components; the
objective is to separate the landscape into landforms or landform segments that
have similar use and management requirements. Each map unit is defined by a
unique combination of soil components and/or miscellaneous areas in predictable
proportions. Some components may be highly contrasting to the other components
of the map unit. The presence of minor components in a map unit in no way
diminishes the usefulness or accuracy of the data. The delineation of such
landforms and landform segments on the map provides sufficient information for the
development of resource plans. If intensive use of small areas is planned, onsite
investigation is needed to define and locate the soils and miscellaneous areas.
Soil scientists make many field observations in the process of producing a soil map.
The frequency of observation is dependent upon several factors, including scale of
mapping, intensity of mapping, design of map units, complexity of the landscape,
and experience of the soil scientist. Observations are made to test and refine the
soil-landscape model and predictions and to verify the classification of the soils at
specific locations. Once the soil-landscape model is refined, a significantly smaller
number of measurements of individual soil properties are made and recorded.
These measurements may include field measurements, such as those for color,
depth to bedrock, and texture, and laboratory measurements, such as those for
content of sand, silt, clay, salt, and other components. Properties of each soil
typically vary from one point to another across the landscape.
Observations for map unit components are aggregated to develop ranges of
characteristics for the components. The aggregated values are presented. Direct
measurements do not exist for every property presented for every map unit
component. Values for some properties are estimated from combinations of other
properties.
While a soil survey is in progress, samples of some of the soils in the area generally
are collected for laboratory analyses and for engineering tests. Soil scientists
interpret the data from these analyses and tests as well as the field-observed
characteristics and the soil properties to determine the expected behavior of the
soils under different uses. Interpretations for all of the soils are field tested through
observation of the soils in different uses and under different levels of management.
Some interpretations are modified to fit local conditions, and some new
interpretations are developed to meet local needs. Data are assembled from other
sources, such as research information, production records, and field experience of
specialists. For example, data on crop yields under defined levels of management
are assembled from farm records and from field or plot experiments on the same
kinds of soil.
Predictions about soil behavior are based not only on soil properties but also on
such variables as climate and biological activity. Soil conditions are predictable over
long periods of time, but they are not predictable from year to year. For example,
soil scientists can predict with a fairly high degree of accuracy that a given soil will
have a high water table within certain depths in most years, but they cannot predict
that a high water table will always be at a specific level in the soil on a specific date.
After soil scientists located and identified the significant natural bodies of soil in the
survey area, they drew the boundaries of these bodies on aerial photographs and
Custom Soil Resource Report
6
1/16/18
identified each as a specific map unit. Aerial photographs show trees, buildings,
fields, roads, and rivers, all of which help in locating boundaries accurately.
Custom Soil Resource Report
7
1/16/18
Soil Map
The soil map section includes the soil map for the defined area of interest, a list of
soil map units on the map and extent of each map unit, and cartographic symbols
displayed on the map. Also presented are various metadata about data used to
produce the map, and a description of each soil map unit.
8
1/16/18
9
Custom Soil Resource Report
Soil Map
43384204338430433844043384504338460433847043384804338490433850043385104338520433853043385404338420433843043384404338450433846043384704338480433849043385004338510433852043385304338540340010 340020 340030 340040 340050 340060 340070 340080 340090 340100
340010 340020 340030 340040 340050 340060 340070 340080 340090 340100
39° 10' 53'' N 106° 51' 8'' W39° 10' 53'' N106° 51' 4'' W39° 10' 49'' N
106° 51' 8'' W39° 10' 49'' N
106° 51' 4'' WN
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84
0 30 60 120 180
Feet
0 5 10 20 30
Meters
Map Scale: 1:622 if printed on A portrait (8.5" x 11") sheet.
Soil Map may not be valid at this scale.
1/16/18
MAP LEGEND MAP INFORMATION
Area of Interest (AOI)
Area of Interest (AOI)
Soils
Soil Map Unit Polygons
Soil Map Unit Lines
Soil Map Unit Points
Special Point Features
Blowout
Borrow Pit
Clay Spot
Closed Depression
Gravel Pit
Gravelly Spot
Landfill
Lava Flow
Marsh or swamp
Mine or Quarry
Miscellaneous Water
Perennial Water
Rock Outcrop
Saline Spot
Sandy Spot
Severely Eroded Spot
Sinkhole
Slide or Slip
Sodic Spot
Spoil Area
Stony Spot
Very Stony Spot
Wet Spot
Other
Special Line Features
Water Features
Streams and Canals
Transportation
Rails
Interstate Highways
US Routes
Major Roads
Local Roads
Background
Aerial Photography
The soil surveys that comprise your AOI were mapped at
1:24,000.
Warning: Soil Map may not be valid at this scale.
Enlargement of maps beyond the scale of mapping can cause
misunderstanding of the detail of mapping and accuracy of soil
line placement. The maps do not show the small areas of
contrasting soils that could have been shown at a more detailed
scale.
Please rely on the bar scale on each map sheet for map
measurements.
Source of Map: Natural Resources Conservation Service
Web Soil Survey URL:
Coordinate System: Web Mercator (EPSG:3857)
Maps from the Web Soil Survey are based on the Web Mercator
projection, which preserves direction and shape but distorts
distance and area. A projection that preserves area, such as the
Albers equal-area conic projection, should be used if more
accurate calculations of distance or area are required.
This product is generated from the USDA-NRCS certified data as
of the version date(s) listed below.
Soil Survey Area: Aspen-Gypsum Area, Colorado, Parts of
Eagle, Garfield, and Pitkin Counties
Survey Area Data: Version 7, Sep 22, 2014
Soil map units are labeled (as space allows) for map scales
1:50,000 or larger.
Date(s) aerial images were photographed: Aug 12, 2011—Sep
22, 2011
The orthophoto or other base map on which the soil lines were
compiled and digitized probably differs from the background
Custom Soil Resource Report
10
1/16/18
MAP LEGEND MAP INFORMATION
imagery displayed on these maps. As a result, some minor
shifting of map unit boundaries may be evident.
Custom Soil Resource Report
11
1/16/18
Map Unit Legend
Aspen-Gypsum Area, Colorado, Parts of Eagle, Garfield, and Pitkin Counties (CO655)
Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI
14 Callings-Yeljack complex, 25 to
65 percent slopes
0.2 11.5%
117 Yeljack-Callings complex, 12 to
25 percent slopes
1.7 88.5%
Totals for Area of Interest 1.9 100.0%
Map Unit Descriptions
The map units delineated on the detailed soil maps in a soil survey represent the
soils or miscellaneous areas in the survey area. The map unit descriptions, along
with the maps, can be used to determine the composition and properties of a unit.
A map unit delineation on a soil map represents an area dominated by one or more
major kinds of soil or miscellaneous areas. A map unit is identified and named
according to the taxonomic classification of the dominant soils. Within a taxonomic
class there are precisely defined limits for the properties of the soils. On the
landscape, however, the soils are natural phenomena, and they have the
characteristic variability of all natural phenomena. Thus, the range of some
observed properties may extend beyond the limits defined for a taxonomic class.
Areas of soils of a single taxonomic class rarely, if ever, can be mapped without
including areas of other taxonomic classes. Consequently, every map unit is made
up of the soils or miscellaneous areas for which it is named and some minor
components that belong to taxonomic classes other than those of the major soils.
Most minor soils have properties similar to those of the dominant soil or soils in the
map unit, and thus they do not affect use and management. These are called
noncontrasting, or similar, components. They may or may not be mentioned in a
particular map unit description. Other minor components, however, have properties
and behavioral characteristics divergent enough to affect use or to require different
management. These are called contrasting, or dissimilar, components. They
generally are in small areas and could not be mapped separately because of the
scale used. Some small areas of strongly contrasting soils or miscellaneous areas
are identified by a special symbol on the maps. If included in the database for a
given area, the contrasting minor components are identified in the map unit
descriptions along with some characteristics of each. A few areas of minor
components may not have been observed, and consequently they are not
mentioned in the descriptions, especially where the pattern was so complex that it
was impractical to make enough observations to identify all the soils and
miscellaneous areas on the landscape.
The presence of minor components in a map unit in no way diminishes the
usefulness or accuracy of the data. The objective of mapping is not to delineate
pure taxonomic classes but rather to separate the landscape into landforms or
landform segments that have similar use and management requirements. The
delineation of such segments on the map provides sufficient information for the
Custom Soil Resource Report
12
1/16/18
development of resource plans. If intensive use of small areas is planned, however,
onsite investigation is needed to define and locate the soils and miscellaneous
areas.
An identifying symbol precedes the map unit name in the map unit descriptions.
Each description includes general facts about the unit and gives important soil
properties and qualities.
Soils that have profiles that are almost alike make up a soil series. Except for
differences in texture of the surface layer, all the soils of a series have major
horizons that are similar in composition, thickness, and arrangement.
Soils of one series can differ in texture of the surface layer, slope, stoniness,
salinity, degree of erosion, and other characteristics that affect their use. On the
basis of such differences, a soil series is divided into soil phases. Most of the areas
shown on the detailed soil maps are phases of soil series. The name of a soil phase
commonly indicates a feature that affects use or management. For example, Alpha
silt loam, 0 to 2 percent slopes, is a phase of the Alpha series.
Some map units are made up of two or more major soils or miscellaneous areas.
These map units are complexes, associations, or undifferentiated groups.
A complex consists of two or more soils or miscellaneous areas in such an intricate
pattern or in such small areas that they cannot be shown separately on the maps.
The pattern and proportion of the soils or miscellaneous areas are somewhat similar
in all areas. Alpha-Beta complex, 0 to 6 percent slopes, is an example.
An association is made up of two or more geographically associated soils or
miscellaneous areas that are shown as one unit on the maps. Because of present
or anticipated uses of the map units in the survey area, it was not considered
practical or necessary to map the soils or miscellaneous areas separately. The
pattern and relative proportion of the soils or miscellaneous areas are somewhat
similar. Alpha-Beta association, 0 to 2 percent slopes, is an example.
An undifferentiated group is made up of two or more soils or miscellaneous areas
that could be mapped individually but are mapped as one unit because similar
interpretations can be made for use and management. The pattern and proportion
of the soils or miscellaneous areas in a mapped area are not uniform. An area can
be made up of only one of the major soils or miscellaneous areas, or it can be made
up of all of them. Alpha and Beta soils, 0 to 2 percent slopes, is an example.
Some surveys include miscellaneous areas. Such areas have little or no soil
material and support little or no vegetation. Rock outcrop is an example.
Custom Soil Resource Report
13
1/16/18
Aspen-Gypsum Area, Colorado, Parts of Eagle, Garfield, and Pitkin
Counties
14—Callings-Yeljack complex, 25 to 65 percent slopes
Map Unit Setting
National map unit symbol: jq4z
Elevation: 7,500 to 9,500 feet
Mean annual precipitation: 18 to 20 inches
Mean annual air temperature: 39 to 41 degrees F
Frost-free period: 70 to 80 days
Farmland classification: Not prime farmland
Map Unit Composition
Callings and similar soils: 50 percent
Yeljack and similar soils: 40 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Callings
Setting
Landform: Ridges, mountain slopes
Landform position (three-dimensional): Mountainflank
Down-slope shape: Convex
Across-slope shape: Convex
Parent material: Alluvium derived from sandstone and/or colluvium derived from
sandstone
Typical profile
H1 - 0 to 6 inches: loam
H2 - 6 to 12 inches: gravelly loam
H3 - 12 to 34 inches: very cobbly clay loam
H4 - 34 to 53 inches: very gravelly clay loam
H5 - 53 to 60 inches: very cobbly sandy clay loam
Properties and qualities
Slope: 25 to 65 percent
Depth to restrictive feature: More than 80 inches
Natural drainage class: Well drained
Runoff class: Very high
Capacity of the most limiting layer to transmit water (Ksat): Moderately low to
moderately high (0.06 to 0.20 in/hr)
Depth to water table: More than 80 inches
Frequency of flooding: None
Frequency of ponding: None
Salinity, maximum in profile: Nonsaline to very slightly saline (0.0 to 2.0
mmhos/cm)
Available water storage in profile: Moderate (about 6.3 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 7e
Hydrologic Soil Group: C
Ecological site: Brushy Loam (R048AY238CO)
Other vegetative classification: BRUSHY LOAM (null_4)
Custom Soil Resource Report
14
1/16/18
Hydric soil rating: No
Description of Yeljack
Setting
Landform: Mountain slopes
Landform position (three-dimensional): Mountainflank
Down-slope shape: Linear
Across-slope shape: Linear
Parent material: Alluvium derived from sandstone and/or eolian deposits
Typical profile
H1 - 0 to 10 inches: silt loam
H2 - 10 to 24 inches: silty clay loam
H3 - 24 to 60 inches: clay loam
Properties and qualities
Slope: 25 to 65 percent
Depth to restrictive feature: More than 80 inches
Natural drainage class: Well drained
Runoff class: Very high
Capacity of the most limiting layer to transmit water (Ksat): Moderately high (0.20
to 0.60 in/hr)
Depth to water table: More than 80 inches
Frequency of flooding: None
Frequency of ponding: None
Available water storage in profile: High (about 11.3 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 7e
Hydrologic Soil Group: C
Ecological site: Mountain Loam (R048AY228CO)
Other vegetative classification: Mountain Loam (null_42)
Hydric soil rating: No
117—Yeljack-Callings complex, 12 to 25 percent slopes
Map Unit Setting
National map unit symbol: jq4t
Elevation: 7,500 to 9,500 feet
Mean annual precipitation: 18 to 20 inches
Mean annual air temperature: 39 to 41 degrees F
Frost-free period: 70 to 80 days
Farmland classification: Not prime farmland
Map Unit Composition
Yeljack and similar soils: 50 percent
Callings and similar soils: 40 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Custom Soil Resource Report
15
1/16/18
Description of Yeljack
Setting
Landform: Structural benches, mountains
Landform position (three-dimensional): Mountainflank
Down-slope shape: Linear
Across-slope shape: Linear
Parent material: Alluvium derived from sandstone and/or eolian deposits
Typical profile
H1 - 0 to 10 inches: silt loam
H2 - 10 to 24 inches: silty clay loam
H3 - 24 to 60 inches: clay loam
Properties and qualities
Slope: 12 to 25 percent
Depth to restrictive feature: More than 80 inches
Natural drainage class: Well drained
Runoff class: High
Capacity of the most limiting layer to transmit water (Ksat): Moderately high (0.20
to 0.60 in/hr)
Depth to water table: More than 80 inches
Frequency of flooding: None
Frequency of ponding: None
Available water storage in profile: High (about 11.3 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 6e
Hydrologic Soil Group: C
Ecological site: Mountain Loam (R048AY228CO)
Other vegetative classification: Mountain Loam (null_42)
Hydric soil rating: No
Description of Callings
Setting
Landform: Ridges, mountains
Landform position (three-dimensional): Mountainflank
Down-slope shape: Linear
Across-slope shape: Linear
Parent material: Alluvium derived from sandstone and/or colluvium derived from
sandstone
Typical profile
H1 - 0 to 6 inches: loam
H2 - 6 to 12 inches: gravelly loam
H3 - 12 to 34 inches: very cobbly clay loam
H4 - 34 to 53 inches: very gravelly clay loam
H5 - 53 to 60 inches: very cobbly sandy clay loam
Properties and qualities
Slope: 12 to 25 percent
Depth to restrictive feature: More than 80 inches
Natural drainage class: Well drained
Runoff class: High
Custom Soil Resource Report
16
1/16/18
Capacity of the most limiting layer to transmit water (Ksat): Moderately low to
moderately high (0.06 to 0.20 in/hr)
Depth to water table: More than 80 inches
Frequency of flooding: None
Frequency of ponding: None
Salinity, maximum in profile: Nonsaline to very slightly saline (0.0 to 2.0
mmhos/cm)
Available water storage in profile: Moderate (about 6.3 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 6e
Hydrologic Soil Group: C
Ecological site: Brushy Loam (R048AY238CO)
Other vegetative classification: BRUSHY LOAM (null_4)
Hydric soil rating: No
Custom Soil Resource Report
17
1/16/18
References
American Association of State Highway and Transportation Officials (AASHTO).
2004. Standard specifications for transportation materials and methods of sampling
and testing. 24th edition.
American Society for Testing and Materials (ASTM). 2005. Standard classification of
soils for engineering purposes. ASTM Standard D2487-00.
Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of
wetlands and deep-water habitats of the United States. U.S. Fish and Wildlife
Service FWS/OBS-79/31.
Federal Register. July 13, 1994. Changes in hydric soils of the United States.
Federal Register. September 18, 2002. Hydric soils of the United States.
Hurt, G.W., and L.M. Vasilas, editors. Version 6.0, 2006. Field indicators of hydric
soils in the United States.
National Research Council. 1995. Wetlands: Characteristics and boundaries.
Soil Survey Division Staff. 1993. Soil survey manual. Soil Conservation Service.
U.S. Department of Agriculture Handbook 18. http://www.nrcs.usda.gov/wps/portal/
nrcs/detail/national/soils/?cid=nrcs142p2_054262
Soil Survey Staff. 1999. Soil taxonomy: A basic system of soil classification for
making and interpreting soil surveys. 2nd edition. Natural Resources Conservation
Service, U.S. Department of Agriculture Handbook 436. http://
www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?cid=nrcs142p2_053577
Soil Survey Staff. 2010. Keys to soil taxonomy. 11th edition. U.S. Department of
Agriculture, Natural Resources Conservation Service. http://
www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?cid=nrcs142p2_053580
Tiner, R.W., Jr. 1985. Wetlands of Delaware. U.S. Fish and Wildlife Service and
Delaware Department of Natural Resources and Environmental Control, Wetlands
Section.
United States Army Corps of Engineers, Environmental Laboratory. 1987. Corps of
Engineers wetlands delineation manual. Waterways Experiment Station Technical
Report Y-87-1.
United States Department of Agriculture, Natural Resources Conservation Service.
National forestry manual. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/
home/?cid=nrcs142p2_053374
United States Department of Agriculture, Natural Resources Conservation Service.
National range and pasture handbook. http://www.nrcs.usda.gov/wps/portal/nrcs/
detail/national/landuse/rangepasture/?cid=stelprdb1043084
18
1/16/18
United States Department of Agriculture, Natural Resources Conservation Service.
National soil survey handbook, title 430-VI. http://www.nrcs.usda.gov/wps/portal/
nrcs/detail/soils/scientists/?cid=nrcs142p2_054242
United States Department of Agriculture, Natural Resources Conservation Service.
2006. Land resource regions and major land resource areas of the United States,
the Caribbean, and the Pacific Basin. U.S. Department of Agriculture Handbook
296. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?
cid=nrcs142p2_053624
United States Department of Agriculture, Soil Conservation Service. 1961. Land
capability classification. U.S. Department of Agriculture Handbook 210. http://
www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs142p2_052290.pdf
Custom Soil Resource Report
19
1/16/18
2
Appendix B--FEMA FIRM Map
1/16/18
1/16/18
3
Appendix C--Plan Set
1/16/18
7/5/2017DATE OF PUBLICATIONC100COVER SHEETTHUNDERBOWL
395 THUNDERBOWL LN. ASPEN, CO
816111/18/2018PERMITWOODY CREEK ENGINEERING, LLCP.O. BOX 575WOODY CREEK, COLORADO 81656(P): 970-429-8297WOODYCREEKENGINEERING.COMTHUNDERBOWL395 THUNDERBOWL LN. ASPEN, CO81611NOTES:1.ALL MATERIALS, WORKMANSHIP, AND CONSTRUCTION OF PUBLICIMPROVEMENTS SHALL MEET OR EXCEED THE STANDARDS ANDSPECIFICATIONS SET FORTH IN THE CITY OF ASPEN ("COA") MUNICIPALCODE, COA TECHNICAL MANUALS, AND APPLICABLESTATE AND FEDERAL REGULATIONS. WHERE THERE IS CONFLICT BETWEENTHESE PLANS AND THE TECHNICAL MANUAL OR ANY APPLICABLESTANDARDS, THE HIGHER QUALITY STANDARD SHALL APPLY. ALL UTILITYWORK SHALL BE INSPECTED AND APPROVED BY THE UTILITY.2.THE CONTRACTOR IS SPECIFICALLY CAUTIONED THAT THE LOCATIONAND/OR ELEVATION OF EXISTING UTILITIES AS SHOWN ON THESE PLANS ISBASED ON RECORDS OF THE VARIOUS UTILITY COMPANIES AND, WHEREPOSSIBLE, MEASUREMENTS TAKEN IN THE FIELD. THE INFORMATION IS NOTTO BE RELIED UPON AS BEING EXACT OR COMPLETE.3.THE CONTRACTOR SHALL HAVE ONE (1) SIGNED COPY OF THEAPPROVED PLANS, ONE (1) COPY OF THE APPROPRIATE CRITERIA ANDSPECIFICATIONS, AND A COPY OF ANY PERMITS AND EXTENSIONAGREEMENTS NEEDED FOR THE JOB ONSITE AT ALL TIMES.4.THE CONTRACTOR SHALL BE RESPONSIBLE FOR ALL ASPECTS OFSAFETY INCLUDING, BUT NOT LIMITED TO, EXCAVATION, TRENCHING,SHORING,TRAFFIC CONTROL, AND SECURITY.5.IF DURING THE CONSTRUCTION PROCESS CONDITIONS AREENCOUNTERED WHICH COULD INDICATE A SITUATION THAT IS NOTIDENTIFIED IN THE PLANS OR SPECIFICATIONS, THE CONTRACTOR SHALLCONTACT THE WOODY CREEK ENGINEERING, LLC IMMEDIATELY.6.ALL REFERENCES TO ANY PUBLISHED STANDARDS SHALL REFER TOTHE LATEST REVISION OF SAID STANDARD UNLESS SPECIFICALLY STATEDOTHERWISE.7.THE CONTRACTOR SHALL SUBMIT A TRAFFIC CONTROL PLAN INACCORDANCE WITH MUTCD TO THE APPROPRIATE RIGHT-OF-WAYAUTHORITY (TOWN, COUNTY OR STATE) FOR APPROVAL PRIOR TO ANYCONSTRUCTION ACTIVITIES WITHIN OR AFFECTING THE RIGHT-OF-WAY.THE CONTRACTOR SHALL BE RESPONSIBLE FOR PROVIDING ANY AND ALLTRAFFIC CONTROL DEVICES AS MAY BE REQUIRED BY THECONSTRUCTION ACTIVITIES.8.THE CONTRACTOR IS RESPONSIBLE FOR PROVIDING ALL LABOR ANDMATERIALS NECESSARY FOR THE COMPLETION OF THE INTENDEDIMPROVEMENTS SHOWN ON THESE DRAWINGS OR AS DESIGNATED TO BEPROVIDED, INSTALLED, OR CONSTRUCTED UNLESS SPECIFICALLYNOTED OTHERWISE.9.THE CONTRACTOR SHALL BE RESPONSIBLE FOR KEEPING ROADWAYSFREE AND CLEAR OF ALL CONSTRUCTION DEBRIS AND DIRT TRACKED FROMTHE SITE.10.THE CONTRACTOR SHALL BE RESPONSIBLE FOR RECORDING AS-BUILTINFORMATION ON A SET OF RECORD DRAWINGS KEPT ON THECONSTRUCTION SITE AND AVAILABLE AT ALL TIMES.11.DIMENSIONS FOR LAYOUT AND CONSTRUCTION ARE NOT TO BESCALED FROM ANY DRAWING. IF PERTINENT DIMENSIONS ARE NOT SHOWN,CONTACT WOODY CREEK ENGINEERING, LLC FOR CLARIFICATION ANDANNOTATE THE DIMENSION ON THE AS-BUILT RECORD DRAWINGS.15. THE CONTRACTOR SHALL COMPLY WITH ALL TERMS AND CONDITIONS OFTHE COLORADO PERMIT FOR STORM WATER DISCHARGE, THE STORMWATER MANAGEMENT PLAN, AND THE EROSION CONTROL PLAN.16.ALL STRUCTURAL EROSION CONTROL MEASURES SHALL BEINSTALLED AT THE LIMITS OF CONSTRUCTION PRIOR TO ANY OTHEREARTH-DISTURBING ACTIVITY. ALL EROSION CONTROL MEASURES SHALL BEMAINTAINED IN GOOD REPAIR BY THE CONTRACTOR UNTIL SUCH TIME ASTHE ENTIRE DISTURBED AREA IS STABILIZED WITH HARD SURFACE ORLANDSCAPING.17.THE CONTRACTOR SHALL SEQUENCE INSTALLATION OF UTILITIES INSUCH A MANNER AS TO MINIMIZE POTENTIAL UTILITY CONFLICTS. INGENERAL, STORM SEWER AND SANITARY SEWER SHOULD BECONSTRUCTED PRIOR TO INSTALLATION OF THE WATER LINES AND DRYUTILITIES.VICINITY MAP0100 200 400 800Scale: 1" = 200'N1/11/20181/16/18
EB:1
AREA: 0.69 Acre
30196.82 SF
8250.008255.008260.
0
0
8250.00
8255.00
82
6
0
.
0
0
8240.0
0
8245.00
8240.00
8245.
0
0
8250.008255.008260.
0
0
8250.00
8255.00
82
6
0
.
0
0
8240.0
0
8245.00
8240.00
8245.
0
0
PB:3
178 SF
PB:4
442 SF
PB:7
534 SF
PB:1.7
473 SF
PB:11
172 SF
PB:12
436 SF
PB:13
642 SF
PB:1.0
8818 SF
PB:1.2
1416 SF
PB:9
746 SF
PB:1.4
710 SF
PB:1.3
402 SF
PB:1.1
3773 SF
PB:1.8
704 SF
PB:1.5
1329 SF
PB:1.6
2020 SF
PB:5
1232 SF
PB:2
1076 SFPB:10
285 SF
PB:6
54 SF
PB:8
179 SF
PB:1.9
4565 SF
8236
8237
8238
8240
8241 8242
8242
8242
8241
8241
8241
8242
8243
8244
824682
4
6
8247824582478247824682458248
8
2
4
9
8
2
5
0
8
2
5
1
8
2
5
2
82
5
3
82
5
4
82
5
5
82
5
6
82
5
7
82
5
8
82
5
9
82
6
0
82
6
1
82
6
2
82
5
8
82
5
7
82
5
6 82
5
5
82
5
4
8253
8252
8251
8250
8249
8248 824782478246824582448244SWALE 824582458245824482448243
1/11/2018 DATE OF PUBLICATION
C200
BASINSTHUNDERBOWL 395 THUNDERBOWL LN.ASPEN, CO 816115/25/2017 CONCEPTUAL G&D
WOODY CREEK ENGINEERING, LLC
P.O. BOX 575
WOODY CREEK, COLORADO 81656
(P): 970-429-8297
WOODYCREEKENGINEERING.COM
EXISTING BASINS PROPOSED BASINS
0 10 20 40 80
Scale: 1" = 20'
N
6/23/2017 PROGRESS GRADING
1/18/2018 COA COMMENTS
1/11/2018
1/16/18
W8250.008255.008260.
0
0
8250.00
8255.00
82
6
0
.
0
0
8240.0
0
8245.00
8240.00
8245.
0
0
ECONC:8244.90
CONC:8244.90
CONC:8244.90
8244.90
8246.1 -2.0%-2.0%-2.0%-2.0%
8244.36
8244.68
8244.73
8236
8237
8238
8240
8241 8242
8242
8242
8241
8241
8241
8242
8243
8244
82468
2
4
6
82478245824782478246824582
4
8
8
2
4
9
8
2
5
0
8
2
5
1
8
2
5
2
82
5
3
82
5
4
82
5
5
82
5
6
82
5
7
82
5
8
82
5
9
82
6
0
82
6
1
82
6
2
82
5
8
82
5
7
82
5
6 82
5
5
82
5
4
8253
8252
8251
8250
8249
8248 824782478246824582448244SWALE 824582458245824482448243
G10.00 FT
1/11/2018 DATE OF PUBLICATION
C300
G&D OVERVIEWTHUNDERBOWL395 THUNDERBOWL LN.ASPEN, CO 816115/25/2017 CONCEPTUAL G&D
WOODY CREEK ENGINEERING, LLC
P.O. BOX 575
WOODY CREEK, COLORADO 81656
(P): 970-429-8297
WOODYCREEKENGINEERING.COM
0 10 20 40 80
Scale: 1" = 20'
N
6/23/2017 PROGRESS GRADING
EXISTING CONTOUR
PROPOSED CONTOUR7910
SPOT ELEVATION XXXX.XX
CONC. = CONCRETE
HP = HIGH POINT
TD = TRENCH DRAIN
PROPERTY LINE
1/11/2018 COA COMMENTS
1/11/2018
1/16/18
8250.008250.00
8255.00
8240.0
0
8245.00
8240.00
8245.
0
0
8244.54
8244.93 8244.98
8244.77 8244.90
8244.84
8244.83
INLET 1
RIM:8254.30
INV OUT:8248.30 6" PVC
INLET 3
RIM:8248.19
INV IN:8247.16 6" PVC
INV OUT:8243.61 6" PVC
DS CONNECT 2
RIM:8243.80
INV IN:8242.19 10"
INV OUT:8242.19 10"
INLET 2
RIM:8250.95
INV IN:8247.56 6" PVC
INV OUT:8247.56 6" PVC
DS CONNECT 1
RIM:8243.84
INV IN:8243.28 4" PVC
INV IN:8243.28 6" PVC
INV OUT:8243.28 6"
CONC:8244.90
CONC:8244.90
CONC:8244.90
8244.90
8246.1 -2.0%-2.0%-2.0%-2.0%
INLET 4
RIM:8244.51
INV IN:8243.51 6" PVC
INV OUT:8243.51 6" PVC
8244.36
8244.68
8244.73
823
6
823
7
823
8
824
0
8241 824
2
824
2
824
2
824
1
824
1
8241
8242
8243
8244
82468
2
4
6
82478245824782478246824582488
2
4
9
8
2
5
0
8
2
5
1
8
2
5
2
82
5
3
82
5
4
82
5
5
82
5
6
8249
8248 824782478246824582448244SWALE 824582458245824482448243
TRENCH DRAIN
INLET 6
RIM:8244.70
INV OUT:8242.54 10"
INLET 5
RIM:8244.70
INV IN:8242.63 10"
1/11/2018 DATE OF PUBLICATION
C301
G&D NORTHTHUNDERBOWL395 THUNDERBOWL LN.ASPEN, CO 816115/25/2017 CONCEPTUAL G&D
WOODY CREEK ENGINEERING, LLC
P.O. BOX 575
WOODY CREEK, COLORADO 81656
(P): 970-429-8297
WOODYCREEKENGINEERING.COM
0 5 10 20 40
Scale: 1" = 10'
N
EXISTING CONTOUR
PROPOSED CONTOUR7910
SPOT ELEVATION XXXX.XX
CONC. = CONCRETE
HP = HIGH POINT
TD = TRENCH DRAIN
PROPERTY LINE
6/23/2017 PROGRESS GRADING
1/11/2018 COA COMMENTS
1/11/2018
1/16/18
8251.00 8250.008255.008260.
0
0
8250.00
8255.00
82
6
0
.
0
0
8240.0
0
8245.00
8245.
0
0
8244.54
8244.50
8251.00
8244.50
8244.93 8244.98
8244.77 8244.90
8244.84
8244.83
INLET 1
RIM:8254.30
INV OUT:8248.30 6" PVC
INLET 3
RIM:8248.19
INV IN:8247.16 6" PVC
INV OUT:8243.61 6" PVC
DS CONNECT 2
RIM:8243.80
INV IN:8242.19 10"
INV OUT:8242.19 10"
INLET 2
RIM:8250.95
INV IN:8247.56 6" PVC
INV OUT:8247.56 6" PVC
DS CONNECT 1
RIM:8243.84
INV IN:8243.28 4" PVC
INV IN:8243.28 6" PVC
INV OUT:8243.28 6"
CONC:8244.90
CONC:8244.90
CONC:8244.90
8244.90
8246.1 -2.0%-2.0%-2.0%-2.0%
INLET 4
RIM:8244.51
INV IN:8243.51 6" PVC
INV OUT:8243.51 6" PVC
8244.36
8244.68
8244.73
824
1 824
2
824
2
824
2
8241
8242
8243
8244
82468
2
4
6
82478245824782478246824582488
2
4
9
8
2
5
0
8
2
5
1
8
2
5
2
82
5
3
82
5
4
82
5
5
82
5
6
82
5
7
82
5
8
82
5
9
82
6
0
82
6
1
82
6
2
82
5
8
82
5
7
82
5
6
82
5
5
82
5
4
8253
8252
8251
8250
8249
8248 824782478246824582448244SWALE 824582458245824482448243
TRENCH DRAIN
INLET 6
RIM:8244.70
INV OUT:8242.54 10"
INLET 5
RIM:8244.70
INV IN:8242.63 10"
1/11/2018 DATE OF PUBLICATION
C302
G&D SOUTHTHUNDERBOWL395 THUNDERBOWL LN.ASPEN, CO 816115/25/2017 CONCEPTUAL G&D
WOODY CREEK ENGINEERING, LLC
P.O. BOX 575
WOODY CREEK, COLORADO 81656
(P): 970-429-8297
WOODYCREEKENGINEERING.COM
0 5 10 20 40
Scale: 1" = 10'
N
6/23/2017 PROGRESS GRADING
EXISTING CONTOUR
PROPOSED CONTOUR7910
SPOT ELEVATION XXXX.XX
CONC. = CONCRETE
HP = HIGH POINT
TD = TRENCH DRAIN
PROPERTY LINE
1/11/2018 COA COMMENTS
1/11/2018
1/16/18
ElevationStation
PIPE A PROFILE
8240
8241
8242
8243
8244
8245
8246
8247
8248
8249
8250
8251
8252
8253
8254
8255
8256
8257
8258
8259
8260
-0+020+00 0+20 0+40 0+60 0+80 1+001+09 ElevationStation
Pipe B PROFILE
8240
8241
8242
8243
8244
8245
8246
8247
8248
8249
8250
8251
8252
8253
8254
8255
-0+020+00 0+20 0+40 0+60 0+80 1+00 1+20 1+38
15.40' of 6" PVC @ 4.00%
INLET 3
RIM:8248.19
INV IN:8247.16 6" PVC
INV OUT:8243.61 6" PVC
12.94' of 6" PVC @ 0.76%
INLET 4
RIM:8244.51
INV IN:8243.51 6" PVC
INV OUT:8243.51 6" PVC
30.47' of 6" PVC @ 0.76%
3.00' of 6" PVC @ 4.00%
10.11' of 6" PVC @ 4.00%
36.39' of 6" @ 0.76%
INLET 1
RIM:8254.30
INV OUT:8248.30 6" PVC
INLET 2
RIM:8250.95
INV IN:8247.56 6" PVC
INV OUT:8247.56 6" PVC
TRENCH DRAIN
35.75' of 10" @ 0.76%
12.45' of 10" @ -0.76%
45.16' of 10" @ 0.76%
26.66' of 10" @ 0.76%
INLET 5
RIM:8244.70
INV IN:8242.63 10"
INLET 6
RIM:8244.70
INV OUT:8242.54 10"DS CONNECT 2
RIM:8243.80
INV IN:8242.19 10"
INV OUT:8242.19 10"
1/11/2018 DATE OF PUBLICATION
C400
PIPE PROFILESTHUNDERBOWL395 THUNDERBOWL LN.ASPEN, CO 816115/25/2017 CONCEPTUAL G&D
WOODY CREEK ENGINEERING, LLC
P.O. BOX 575
WOODY CREEK, COLORADO 81656
(P): 970-429-8297
WOODYCREEKENGINEERING.COM
6/23/2017 PROGRESS GRADING
1/18/2018 COA COMMENTS
1/11/2018
1/16/18
1.00 FT
0.57 FT
3.00 FT4.76 FT
1.57 FT
1.00 FT
7.76 FT
1.00 FT
CHECK VALVES
FOUNDATION DRAIN
LIFT STATION PLAN
LIFT OUT ADAPTERS
4"Ø FOUNDATION DRAIN
COLLECTOR PIPER
PRECAST 40" RISERS
PIPES IN (SEE PLAN)
PRECAST SOLID
REMOVABLE LID
STANDARD RISER SECTION(S) WITH
NATIVE BACKFILL
PERFORATED RISER SECTION(S) WITH 3
4"
WASHED ROCK 2 FT AROUND DRYWELL
AND 1 FT BELOW THE DRYWELL
NOTES:
1. PRECAST MANHOLE TO MEET ASTM C-467.
2. THE EDGE OF THE DRYWELL SHALL BE INSTALLED AT LEAST 10 FEET AWAY FROM ANY
FOUNDATION WALL.
3. COMPACT BACKFILL TO 95% STANDARD PROCTOR.
4. BACKFILL EXCAVATION STRUCTURE WITH COMPACTED 1-1/2" WASHED ROCK TO THE TOP
OF THE DRYWELL AND WITH STRUCTURAL NATIVE MATERIAL TO 12" BELOW FINISH GRADE.
COMPACT BACKFILL TO 95% STANDARD PROCTOR.
RECESS MANHOLE
LID 1
8" TO 1
4"
BELOW FINISH GRADE
CAST IRON OR ALUM. MANHOLE STEPS,
POSITION OVER SHELF IN VERTICAL LINE
AT 15" o.c. MAX.
2" DISCHARGE PIPE
FLEXIBLE PLASTIC SEALING COMPUND
(RAM-NEK) AT
ALL JOINTS
4" FOUNDATION DRAIN
DUPLEX GRINDER PUMPS TO HAVE A
QUICK DISCONNECT TO PULL THE PUMPS
OUT OF MANHOLE THROUH THE MANWAY.
PUMPS TO SIT DIRECTLY ON BOTTOM OF
MANHOLE
24Ø
1/11/2018 DATE OF PUBLICATION
C500
DETAILSTHUNDERBOWL 395 THUNDERBOWL LN.ASPEN, CO 816115/25/2017 CONCEPTUAL G&D
WOODY CREEK ENGINEERING, LLC
P.O. BOX 575
WOODY CREEK, COLORADO 81656
(P): 970-429-8297
WOODYCREEKENGINEERING.COM
6/23/2017 PROGRESS GRADING
RAIN GARDEN CROSS SECTION A-A
9" SQUARE STRUCTURAL FOAM GRATE
9" SQUARE GALVANIZED STEEL GRATE
12" SQUARE GALVANIZED STEEL GRATE
TRENCH DRAIN GRATE
INLET TYPE
FOUNDATION DRAIN AND DRYWELL DETAILS
1/11/2018 COA COMMENTS
1/11/2018
1/16/18
8250.00
8255.008260.008250.008255.008260.008240.008245.008240.008245.00
-2.0%
-2.0%
-2.0%-2.0%8
2
3
682
3
7
8
2
3
8
8
2
4
0
82
4
1
8
2
4
2
8
2
4
2
8
2
4
2
82
4
1
82
4
182418242824382448
2
4
6824682478
2
4
5
8
2
4
7
8247
8246
8245 824882498250825182528253825482558256825782588259826082618262825882578256825582548253825282518250824982488247
8247
8246
8245
8244
8244
SWALE82
4
5 82458245 8244824482431/11/2018 DATE OF PUBLICATION
C600
EROSION AND
SEDIMENT
CONTROLTHUNDERBOWL 395 THUNDERBOWL LN.ASPEN, CO 816115/25/2017 CONCEPTUAL G&D
WOODY CREEK ENGINEERING, LLC
P.O. BOX 575
WOODY CREEK, COLORADO 81656
(P): 970-429-8297
WOODYCREEKENGINEERING.COM
0 5 10 20 40
Scale: 1" = 10'NSED. FENCE
6/23/2017 PROGRESS GRADING
PROPERTY LINE
1/11/2018 COA COMMENTS
1/11/2018
1/16/18
W
SS
SS
8250.00
8255.008260.008250.008255.008260.008240.008245.008240.008245.00
E CONC:8244.90CONC:8244.90CONC:8244.908244.908246.1-2.0%
-2.0%
-2.0%-2.0%8244.368244.688244.738
2
3
682
3
7
8
2
3
8
8
2
4
0
82
4
1
8
2
4
2
8
2
4
2
8
2
4
2
82
4
1
82
4
182418242824382448
2
4
6824682478
2
4
5
8
2
4
7
8247
8246
8245 824882498250825182528253825482558256825782588259826082618262825882578256825582548253825282518250824982488247
8247
8246
8245
8244
8244
SWALE82
4
5 82458245 824482448243G
10.00 FT1/11/2018 DATE OF PUBLICATION
C700
UTILITIESTHUNDERBOWL 395 THUNDERBOWL LN.ASPEN, CO 816115/25/2017 CONCEPTUAL G&D
WOODY CREEK ENGINEERING, LLC
P.O. BOX 575
WOODY CREEK, COLORADO 81656
(P): 970-429-8297
WOODYCREEKENGINEERING.COM
0 5 10 20 40
Scale: 1" = 10'NUTILITY SERVICE
E=ELECTRIC
UG=UNDERGROUND GAS
SS=SANITARY SEWER
W=WATER
Tel=PHONE LINE
Cable=CABLE LINE
WATER METER
ELECTRIC METER
W
E
6/23/2017 PROGRESS GRADING
EXISTING CONTOUR
PROPOSED CONTOUR7910
SPOT ELEVATION XXXX.XX
CONC. = CONCRETE
HP = HIGH POINT
TD = TRENCH DRAIN
PROPERTY LINE
1/11/2018 COA COMMENTS
1/11/2018
1/16/18
W
SS
SS
E
-2.0%
-2.0%
-2.0%-2.0%8
2
3
682
3
7
8
2
3
8
8
2
4
0
82
4
1
8
2
4
2
8
2
4
2
8
2
4
2
82
4
1
82
4
182418242824382448
2
4
6824682478
2
4
5
8
2
4
7
8247
8246
8245 824882498250825182528253825482558256825782588259826082618262825882578256825582548253825282518250824982488247
8247
8246
8245
8244
8244
SWALE82
4
5 82458245 824482448243G
10.00 FT1/11/2018 DATE OF PUBLICATION
C800
FOUNDATION DRAIN
PLANTHUNDERBOWL 395 THUNDERBOWL LN.ASPEN, CO 816115/25/2017 CONCEPTUAL G&D
WOODY CREEK ENGINEERING, LLC
P.O. BOX 575
WOODY CREEK, COLORADO 81656
(P): 970-429-8297
WOODYCREEKENGINEERING.COM
0 5 10 20 40
Scale: 1" = 10'NSED. FENCE
6/23/2017 PROGRESS GRADING
PROPERTY LINE
1/11/2018 COA COMMENTS
1/11/2018
1/16/18
4
Appendix D--Hydrologic Calculations
1/16/18
City of Aspen Urban Runoff Management Plan
Chapter 8 – Water Quality 8-30 Rev 11/2014
Figure 8.13 Aspen Water Quality Capture Volume
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100WQCV (watershed-inches) Effective Imperviousness of Tributary Area to BMP (percent)
WQCV
SF
1/16/18
5YR-EB1.xls Page 3
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:Thunderbowl
Catchment ID:EB : 1
I.Catchment Hydrologic Data
Catchment ID =EB : 1
Area =0.693 Acres
Percent Imperviousness =0.00 %
NRCS Soil Type =C A, B, C, or D
II.Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3
Design Storm Return Period, Tr =5 years (input return period for design storm)
C1 =88.80 (input the value of C1)
C2=10.00 (input the value of C2)
C3=1.052 (input the value of C3)
P1=0.64 inches (input one-hr precipitation--see Sheet "Design Info")
III.Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =0.15
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.15
Overide 5-yr. Runoff Coefficient, C =(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land Heavy Tillage/Short Nearly Grassed Paved Areas &
Type Meadow Field Pasture/Bare Swales/Shallow Paved Swales
Lawns Ground Waterways (Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations:Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey-Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.1000 312 0.15 N/A 0.37 14.17
1
2
3
4
5
Sum 312 Computed Tc =14.17
Regional Tc =11.73
User-Entered Tc =11.73
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =1.99 inch/hr Peak Flowrate, Qp =0.207 cfs
Rainfall Intensity at Regional Tc, I =2.23 inch/hr Peak Flowrate, Qp =0.232 cfs
Rainfall Intensity at User-Defined Tc, I =2.23 inch/hr Peak Flowrate, Qp =0.232 cfs
1/16/18
5YR-PB1.0.xls Page 3
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:Thunderbowl
Catchment ID:PB:1.0
I.Catchment Hydrologic Data
Catchment ID =PB:1.0
Area =0.203 Acres
Percent Imperviousness =11.30 %
NRCS Soil Type =C A, B, C, or D
II.Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3
Design Storm Return Period, Tr =5 years (input return period for design storm)
C1 =88.80 (input the value of C1)
C2=10.00 (input the value of C2)
C3=1.052 (input the value of C3)
P1=0.64 inches (input one-hr precipitation--see Sheet "Design Info")
III.Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =0.22
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.22
Overide 5-yr. Runoff Coefficient, C =(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land Heavy Tillage/Short Nearly Grassed Paved Areas &
Type Meadow Field Pasture/Bare Swales/Shallow Paved Swales
Lawns Ground Waterways (Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations:Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey-Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.1000 156 0.22 N/A 0.28 9.31
1
2
3
4
5
Sum 156 Computed Tc =9.31
Regional Tc =10.87
User-Entered Tc =9.31
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =2.52 inch/hr Peak Flowrate, Qp =0.111 cfs
Rainfall Intensity at Regional Tc, I =2.33 inch/hr Peak Flowrate, Qp =0.103 cfs
Rainfall Intensity at User-Defined Tc, I =2.52 inch/hr Peak Flowrate, Qp =0.111 cfs
1/16/18
5YR-PB2.xls Page 3
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:Thunderbowl
Catchment ID:PB:2
I.Catchment Hydrologic Data
Catchment ID =PB:2
Area =0.025 Acres
Percent Imperviousness =0.00 %
NRCS Soil Type =C A, B, C, or D
II.Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3
Design Storm Return Period, Tr =5 years (input return period for design storm)
C1 =88.80 (input the value of C1)
C2=10.00 (input the value of C2)
C3=1.052 (input the value of C3)
P1=0.64 inches (input one-hr precipitation--see Sheet "Design Info")
III.Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =0.15
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.15
Overide 5-yr. Runoff Coefficient, C =(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land Heavy Tillage/Short Nearly Grassed Paved Areas &
Type Meadow Field Pasture/Bare Swales/Shallow Paved Swales
Lawns Ground Waterways (Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations:Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey-Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.5000 5 0.15 N/A 0.08 1.05
1
2
3
4
5
Sum 5 Computed Tc =1.05
Regional Tc =10.03
User-Entered Tc =5.00
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =4.54 inch/hr Peak Flowrate, Qp =0.017 cfs
Rainfall Intensity at Regional Tc, I =2.43 inch/hr Peak Flowrate, Qp =0.009 cfs
Rainfall Intensity at User-Defined Tc, I =3.29 inch/hr Peak Flowrate, Qp =0.012 cfs
1/16/18
5YR-PB3.xls Page 3
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:Thunderbowl
Catchment ID:PB:3
I.Catchment Hydrologic Data
Catchment ID =PB:3
Area =0.004 Acres
Percent Imperviousness =100.00 %
NRCS Soil Type =C A, B, C, or D
II.Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3
Design Storm Return Period, Tr =5 years (input return period for design storm)
C1 =88.80 (input the value of C1)
C2=10.00 (input the value of C2)
C3=1.052 (input the value of C3)
P1=0.64 inches (input one-hr precipitation--see Sheet "Design Info")
III.Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =0.90
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.90
Overide 5-yr. Runoff Coefficient, C =(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land Heavy Tillage/Short Nearly Grassed Paved Areas &
Type Meadow Field Pasture/Bare Swales/Shallow Paved Swales
Lawns Ground Waterways (Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations:Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey-Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.5000 5 0.90 N/A 0.37 0.23
1
2
3
4
5
Sum 5 Computed Tc =0.23
Regional Tc =10.03
User-Entered Tc =5.00
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =4.92 inch/hr Peak Flowrate, Qp =0.018 cfs
Rainfall Intensity at Regional Tc, I =2.43 inch/hr Peak Flowrate, Qp =0.009 cfs
Rainfall Intensity at User-Defined Tc, I =3.29 inch/hr Peak Flowrate, Qp =0.012 cfs
1/16/18
5YR-PB4.xls Page 3
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:Thunderbowl
Catchment ID:PB:4
I.Catchment Hydrologic Data
Catchment ID =PB:4
Area =0.010 Acres
Percent Imperviousness =0.00 %
NRCS Soil Type =C A, B, C, or D
II.Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3
Design Storm Return Period, Tr =5 years (input return period for design storm)
C1 =88.80 (input the value of C1)
C2=10.00 (input the value of C2)
C3=1.052 (input the value of C3)
P1=0.64 inches (input one-hr precipitation--see Sheet "Design Info")
III.Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =0.15
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.15
Overide 5-yr. Runoff Coefficient, C =(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land Heavy Tillage/Short Nearly Grassed Paved Areas &
Type Meadow Field Pasture/Bare Swales/Shallow Paved Swales
Lawns Ground Waterways (Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations:Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey-Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.5000 5 0.15 N/A 0.08 1.05
1
2
3
4
5
Sum 5 Computed Tc =1.05
Regional Tc =10.03
User-Entered Tc =5.00
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =4.54 inch/hr Peak Flowrate, Qp =0.007 cfs
Rainfall Intensity at Regional Tc, I =2.43 inch/hr Peak Flowrate, Qp =0.004 cfs
Rainfall Intensity at User-Defined Tc, I =3.29 inch/hr Peak Flowrate, Qp =0.005 cfs
1/16/18
5YR-PB5.xls Page 3
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:Thunderbowl
Catchment ID:PB:5
I.Catchment Hydrologic Data
Catchment ID =PB:5
Area =0.028 Acres
Percent Imperviousness =100.00 %
NRCS Soil Type =C A, B, C, or D
II.Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3
Design Storm Return Period, Tr =5 years (input return period for design storm)
C1 =88.80 (input the value of C1)
C2=10.00 (input the value of C2)
C3=1.052 (input the value of C3)
P1=0.64 inches (input one-hr precipitation--see Sheet "Design Info")
III.Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =0.90
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.90
Overide 5-yr. Runoff Coefficient, C =(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land Heavy Tillage/Short Nearly Grassed Paved Areas &
Type Meadow Field Pasture/Bare Swales/Shallow Paved Swales
Lawns Ground Waterways (Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations:Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey-Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.5000 5 0.90 N/A 0.37 0.23
1
2
3
4
5
Sum 5 Computed Tc =0.23
Regional Tc =10.03
User-Entered Tc =5.00
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =4.92 inch/hr Peak Flowrate, Qp =0.124 cfs
Rainfall Intensity at Regional Tc, I =2.43 inch/hr Peak Flowrate, Qp =0.061 cfs
Rainfall Intensity at User-Defined Tc, I =3.29 inch/hr Peak Flowrate, Qp =0.083 cfs
1/16/18
5YR-PB6.xls Page 3
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:Thunderbowl
Catchment ID:PB:6
I.Catchment Hydrologic Data
Catchment ID =PB:6
Area =0.001 Acres
Percent Imperviousness =100.00 %
NRCS Soil Type =C A, B, C, or D
II.Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3
Design Storm Return Period, Tr =5 years (input return period for design storm)
C1 =88.80 (input the value of C1)
C2=10.00 (input the value of C2)
C3=1.052 (input the value of C3)
P1=0.64 inches (input one-hr precipitation--see Sheet "Design Info")
III.Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =0.90
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.90
Overide 5-yr. Runoff Coefficient, C =(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land Heavy Tillage/Short Nearly Grassed Paved Areas &
Type Meadow Field Pasture/Bare Swales/Shallow Paved Swales
Lawns Ground Waterways (Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations:Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey-Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.5000 5 0.90 N/A 0.37 0.23
1
2
3
4
5
Sum 5 Computed Tc =0.23
Regional Tc =10.03
User-Entered Tc =5.00
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =4.92 inch/hr Peak Flowrate, Qp =0.004 cfs
Rainfall Intensity at Regional Tc, I =2.43 inch/hr Peak Flowrate, Qp =0.002 cfs
Rainfall Intensity at User-Defined Tc, I =3.29 inch/hr Peak Flowrate, Qp =0.003 cfs
1/16/18
5YR-PB7.xls Page 3
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:Thunderbowl
Catchment ID:PB:7
I.Catchment Hydrologic Data
Catchment ID =PB:7
Area =0.012 Acres
Percent Imperviousness =0.00 %
NRCS Soil Type =C A, B, C, or D
II.Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3
Design Storm Return Period, Tr =5 years (input return period for design storm)
C1 =88.80 (input the value of C1)
C2=10.00 (input the value of C2)
C3=1.052 (input the value of C3)
P1=0.64 inches (input one-hr precipitation--see Sheet "Design Info")
III.Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =0.15
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.15
Overide 5-yr. Runoff Coefficient, C =(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land Heavy Tillage/Short Nearly Grassed Paved Areas &
Type Meadow Field Pasture/Bare Swales/Shallow Paved Swales
Lawns Ground Waterways (Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations:Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey-Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.5000 5 0.15 N/A 0.08 1.05
1
2
3
4
5
Sum 5 Computed Tc =1.05
Regional Tc =10.03
User-Entered Tc =5.00
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =4.54 inch/hr Peak Flowrate, Qp =0.008 cfs
Rainfall Intensity at Regional Tc, I =2.43 inch/hr Peak Flowrate, Qp =0.004 cfs
Rainfall Intensity at User-Defined Tc, I =3.29 inch/hr Peak Flowrate, Qp =0.006 cfs
1/16/18
5YR-PB8.xls Page 3
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:Thunderbowl
Catchment ID:PB:8
I.Catchment Hydrologic Data
Catchment ID =PB:8
Area =0.004 Acres
Percent Imperviousness =100.00 %
NRCS Soil Type =C A, B, C, or D
II.Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3
Design Storm Return Period, Tr =5 years (input return period for design storm)
C1 =88.80 (input the value of C1)
C2=10.00 (input the value of C2)
C3=1.052 (input the value of C3)
P1=0.64 inches (input one-hr precipitation--see Sheet "Design Info")
III.Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =0.90
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.90
Overide 5-yr. Runoff Coefficient, C =(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land Heavy Tillage/Short Nearly Grassed Paved Areas &
Type Meadow Field Pasture/Bare Swales/Shallow Paved Swales
Lawns Ground Waterways (Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations:Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey-Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.5000 5 0.90 N/A 0.37 0.23
1
2
3
4
5
Sum 5 Computed Tc =0.23
Regional Tc =10.03
User-Entered Tc =5.00
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =4.92 inch/hr Peak Flowrate, Qp =0.016 cfs
Rainfall Intensity at Regional Tc, I =2.43 inch/hr Peak Flowrate, Qp =0.008 cfs
Rainfall Intensity at User-Defined Tc, I =3.29 inch/hr Peak Flowrate, Qp =0.010 cfs
1/16/18
5YR-PB9.xls Page 3
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:Thunderbowl
Catchment ID:PB:9
I.Catchment Hydrologic Data
Catchment ID =PB:9
Area =0.017 Acres
Percent Imperviousness =20.10 %
NRCS Soil Type =C A, B, C, or D
II.Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3
Design Storm Return Period, Tr =5 years (input return period for design storm)
C1 =88.80 (input the value of C1)
C2=10.00 (input the value of C2)
C3=1.052 (input the value of C3)
P1=0.64 inches (input one-hr precipitation--see Sheet "Design Info")
III.Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =0.26
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.26
Overide 5-yr. Runoff Coefficient, C =(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land Heavy Tillage/Short Nearly Grassed Paved Areas &
Type Meadow Field Pasture/Bare Swales/Shallow Paved Swales
Lawns Ground Waterways (Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations:Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey-Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.5000 5 0.26 N/A 0.09 0.93
1
2
3
4
5
Sum 5 Computed Tc =0.93
Regional Tc =10.03
User-Entered Tc =5.00
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =4.59 inch/hr Peak Flowrate, Qp =0.020 cfs
Rainfall Intensity at Regional Tc, I =2.43 inch/hr Peak Flowrate, Qp =0.011 cfs
Rainfall Intensity at User-Defined Tc, I =3.29 inch/hr Peak Flowrate, Qp =0.014 cfs
1/16/18
5YR-PB10.xls Page 3
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:Thunderbowl
Catchment ID:PB:10
I.Catchment Hydrologic Data
Catchment ID =PB:10
Area =0.007 Acres
Percent Imperviousness =100.00 %
NRCS Soil Type =C A, B, C, or D
II.Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3
Design Storm Return Period, Tr =5 years (input return period for design storm)
C1 =88.80 (input the value of C1)
C2=10.00 (input the value of C2)
C3=1.052 (input the value of C3)
P1=0.64 inches (input one-hr precipitation--see Sheet "Design Info")
III.Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =0.90
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.90
Overide 5-yr. Runoff Coefficient, C =(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land Heavy Tillage/Short Nearly Grassed Paved Areas &
Type Meadow Field Pasture/Bare Swales/Shallow Paved Swales
Lawns Ground Waterways (Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations:Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey-Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.5000 5 0.90 N/A 0.37 0.23
1
2
3
4
5
Sum 5 Computed Tc =0.23
Regional Tc =10.03
User-Entered Tc =5.00
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =4.92 inch/hr Peak Flowrate, Qp =0.031 cfs
Rainfall Intensity at Regional Tc, I =2.43 inch/hr Peak Flowrate, Qp =0.015 cfs
Rainfall Intensity at User-Defined Tc, I =3.29 inch/hr Peak Flowrate, Qp =0.021 cfs
1/16/18
5YR-PB11.xls Page 3
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:Thunderbowl
Catchment ID:PB:11
I.Catchment Hydrologic Data
Catchment ID =PB:11
Area =0.002 Acres
Percent Imperviousness =100.00 %
NRCS Soil Type =C A, B, C, or D
II.Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3
Design Storm Return Period, Tr =5 years (input return period for design storm)
C1 =88.80 (input the value of C1)
C2=10.00 (input the value of C2)
C3=1.052 (input the value of C3)
P1=0.64 inches (input one-hr precipitation--see Sheet "Design Info")
III.Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =0.90
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.90
Overide 5-yr. Runoff Coefficient, C =(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land Heavy Tillage/Short Nearly Grassed Paved Areas &
Type Meadow Field Pasture/Bare Swales/Shallow Paved Swales
Lawns Ground Waterways (Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations:Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey-Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.5000 5 0.90 N/A 0.37 0.23
1
2
3
4
5
Sum 5 Computed Tc =0.23
Regional Tc =10.03
User-Entered Tc =5.00
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =4.92 inch/hr Peak Flowrate, Qp =0.009 cfs
Rainfall Intensity at Regional Tc, I =2.43 inch/hr Peak Flowrate, Qp =0.004 cfs
Rainfall Intensity at User-Defined Tc, I =3.29 inch/hr Peak Flowrate, Qp =0.006 cfs
1/16/18
5YR-PB12.xls Page 3
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:Thunderbowl
Catchment ID:PB:12
I.Catchment Hydrologic Data
Catchment ID =PB:12
Area =0.010 Acres
Percent Imperviousness =81.60 %
NRCS Soil Type =C A, B, C, or D
II.Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3
Design Storm Return Period, Tr =5 years (input return period for design storm)
C1 =88.80 (input the value of C1)
C2=10.00 (input the value of C2)
C3=1.052 (input the value of C3)
P1=0.64 inches (input one-hr precipitation--see Sheet "Design Info")
III.Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =0.64
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.64
Overide 5-yr. Runoff Coefficient, C =(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land Heavy Tillage/Short Nearly Grassed Paved Areas &
Type Meadow Field Pasture/Bare Swales/Shallow Paved Swales
Lawns Ground Waterways (Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations:Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey-Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.5000 5 0.64 N/A 0.16 0.51
1
2
3
4
5
Sum 5 Computed Tc =0.51
Regional Tc =10.03
User-Entered Tc =5.00
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =4.78 inch/hr Peak Flowrate, Qp =0.031 cfs
Rainfall Intensity at Regional Tc, I =2.43 inch/hr Peak Flowrate, Qp =0.016 cfs
Rainfall Intensity at User-Defined Tc, I =3.29 inch/hr Peak Flowrate, Qp =0.022 cfs
1/16/18
5YR-PB13.xls Page 3
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:Thunderbowl
Catchment ID:PB:13
I.Catchment Hydrologic Data
Catchment ID =PB:13
Area =0.015 Acres
Percent Imperviousness =0.00 %
NRCS Soil Type =C A, B, C, or D
II.Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3
Design Storm Return Period, Tr =5 years (input return period for design storm)
C1 =88.80 (input the value of C1)
C2=10.00 (input the value of C2)
C3=1.052 (input the value of C3)
P1=0.64 inches (input one-hr precipitation--see Sheet "Design Info")
III.Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =0.15
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.15
Overide 5-yr. Runoff Coefficient, C =(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land Heavy Tillage/Short Nearly Grassed Paved Areas &
Type Meadow Field Pasture/Bare Swales/Shallow Paved Swales
Lawns Ground Waterways (Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations:Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey-Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.5000 5 0.15 N/A 0.08 1.05
1
2
3
4
5
Sum 5 Computed Tc =1.05
Regional Tc =10.03
User-Entered Tc =5.00
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =4.54 inch/hr Peak Flowrate, Qp =0.010 cfs
Rainfall Intensity at Regional Tc, I =2.43 inch/hr Peak Flowrate, Qp =0.005 cfs
Rainfall Intensity at User-Defined Tc, I =3.29 inch/hr Peak Flowrate, Qp =0.007 cfs
1/16/18
100YR-EB1.xls Page 3
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:Thunderbowl
Catchment ID:EB : 1
I.Catchment Hydrologic Data
Catchment ID =EB : 1
Area =0.693 Acres
Percent Imperviousness =0.00 %
NRCS Soil Type =C A, B, C, or D
II.Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3
Design Storm Return Period, Tr =100 years (input return period for design storm)
C1 =88.80 (input the value of C1)
C2=10.00 (input the value of C2)
C3=1.052 (input the value of C3)
P1=1.23 inches (input one-hr precipitation--see Sheet "Design Info")
III.Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =0.50
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.15
Overide 5-yr. Runoff Coefficient, C =(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land Heavy Tillage/Short Nearly Grassed Paved Areas &
Type Meadow Field Pasture/Bare Swales/Shallow Paved Swales
Lawns Ground Waterways (Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations:Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey-Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.1000 312 0.15 N/A 0.37 14.17
1
2
3
4
5
Sum 312 Computed Tc =14.17
Regional Tc =11.73
User-Entered Tc =11.73
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =3.83 inch/hr Peak Flowrate, Qp =1.327 cfs
Rainfall Intensity at Regional Tc, I =4.28 inch/hr Peak Flowrate, Qp =1.485 cfs
Rainfall Intensity at User-Defined Tc, I =4.28 inch/hr Peak Flowrate, Qp =1.4845 cfs
1/16/18
100YR-PB1.0.xls Page 3
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:Thunderbowl
Catchment ID:PB:1.0
I.Catchment Hydrologic Data
Catchment ID =PB:1.0
Area =0.203 Acres
Percent Imperviousness =11.30 %
NRCS Soil Type =C A, B, C, or D
II.Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3
Design Storm Return Period, Tr =100 years (input return period for design storm)
C1 =88.80 (input the value of C1)
C2=10.00 (input the value of C2)
C3=1.052 (input the value of C3)
P1=1.23 inches (input one-hr precipitation--see Sheet "Design Info")
III.Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =0.53
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.22
Overide 5-yr. Runoff Coefficient, C =(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land Heavy Tillage/Short Nearly Grassed Paved Areas &
Type Meadow Field Pasture/Bare Swales/Shallow Paved Swales
Lawns Ground Waterways (Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations:Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey-Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.1000 156 0.22 N/A 0.28 9.31
1
2
3
4
5
Sum 156 Computed Tc =9.31
Regional Tc =10.87
User-Entered Tc =9.31
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =4.85 inch/hr Peak Flowrate, Qp =0.526 cfs
Rainfall Intensity at Regional Tc, I =4.47 inch/hr Peak Flowrate, Qp =0.485 cfs
Rainfall Intensity at User-Defined Tc, I =4.85 inch/hr Peak Flowrate, Qp =0.526 cfs
1/16/18
100YR-PB2.xls Page 3
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:Thunderbowl
Catchment ID:PB:2
I.Catchment Hydrologic Data
Catchment ID =PB:2
Area =0.025 Acres
Percent Imperviousness =0.00 %
NRCS Soil Type =C A, B, C, or D
II.Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3
Design Storm Return Period, Tr =100 years (input return period for design storm)
C1 =88.80 (input the value of C1)
C2=10.00 (input the value of C2)
C3=1.052 (input the value of C3)
P1=1.23 inches (input one-hr precipitation--see Sheet "Design Info")
III.Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =0.50
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.15
Overide 5-yr. Runoff Coefficient, C =(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land Heavy Tillage/Short Nearly Grassed Paved Areas &
Type Meadow Field Pasture/Bare Swales/Shallow Paved Swales
Lawns Ground Waterways (Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations:Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey-Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.5000 5 0.15 N/A 0.08 1.05
1
2
3
4
5
Sum 5 Computed Tc =1.05
Regional Tc =10.03
User-Entered Tc =5.00
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =8.72 inch/hr Peak Flowrate, Qp =0.109 cfs
Rainfall Intensity at Regional Tc, I =4.67 inch/hr Peak Flowrate, Qp =0.058 cfs
Rainfall Intensity at User-Defined Tc, I =6.33 inch/hr Peak Flowrate, Qp =0.079 cfs
1/16/18
100YR-PB3.xls Page 3
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:Thunderbowl
Catchment ID:PB:3
I.Catchment Hydrologic Data
Catchment ID =PB:3
Area =0.004 Acres
Percent Imperviousness =100.00 %
NRCS Soil Type =C A, B, C, or D
II.Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3
Design Storm Return Period, Tr =100 years (input return period for design storm)
C1 =88.80 (input the value of C1)
C2=10.00 (input the value of C2)
C3=1.052 (input the value of C3)
P1=1.23 inches (input one-hr precipitation--see Sheet "Design Info")
III.Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =0.96
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.90
Overide 5-yr. Runoff Coefficient, C =(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land Heavy Tillage/Short Nearly Grassed Paved Areas &
Type Meadow Field Pasture/Bare Swales/Shallow Paved Swales
Lawns Ground Waterways (Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations:Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey-Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.5000 5 0.90 N/A 0.37 0.23
1
2
3
4
5
Sum 5 Computed Tc =0.23
Regional Tc =10.03
User-Entered Tc =5.00
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =9.46 inch/hr Peak Flowrate, Qp =0.036 cfs
Rainfall Intensity at Regional Tc, I =4.67 inch/hr Peak Flowrate, Qp =0.018 cfs
Rainfall Intensity at User-Defined Tc, I =6.33 inch/hr Peak Flowrate, Qp =0.024 cfs
1/16/18
100YR-PB4.xls Page 3
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:Thunderbowl
Catchment ID:PB:4
I.Catchment Hydrologic Data
Catchment ID =PB:4
Area =0.010 Acres
Percent Imperviousness =0.00 %
NRCS Soil Type =C A, B, C, or D
II.Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3
Design Storm Return Period, Tr =100 years (input return period for design storm)
C1 =88.80 (input the value of C1)
C2=10.00 (input the value of C2)
C3=1.052 (input the value of C3)
P1=1.23 inches (input one-hr precipitation--see Sheet "Design Info")
III.Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =0.50
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.15
Overide 5-yr. Runoff Coefficient, C =(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land Heavy Tillage/Short Nearly Grassed Paved Areas &
Type Meadow Field Pasture/Bare Swales/Shallow Paved Swales
Lawns Ground Waterways (Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations:Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey-Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.5000 5 0.15 N/A 0.08 1.05
1
2
3
4
5
Sum 5 Computed Tc =1.05
Regional Tc =10.03
User-Entered Tc =5.00
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =8.72 inch/hr Peak Flowrate, Qp =0.045 cfs
Rainfall Intensity at Regional Tc, I =4.67 inch/hr Peak Flowrate, Qp =0.024 cfs
Rainfall Intensity at User-Defined Tc, I =6.33 inch/hr Peak Flowrate, Qp =0.033 cfs
1/16/18
100YR-PB5.xls Page 3
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:Thunderbowl
Catchment ID:PB:5
I.Catchment Hydrologic Data
Catchment ID =PB:5
Area =0.028 Acres
Percent Imperviousness =100.00 %
NRCS Soil Type =C A, B, C, or D
II.Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3
Design Storm Return Period, Tr =100 years (input return period for design storm)
C1 =88.80 (input the value of C1)
C2=10.00 (input the value of C2)
C3=1.052 (input the value of C3)
P1=1.23 inches (input one-hr precipitation--see Sheet "Design Info")
III.Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =0.96
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.90
Overide 5-yr. Runoff Coefficient, C =(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land Heavy Tillage/Short Nearly Grassed Paved Areas &
Type Meadow Field Pasture/Bare Swales/Shallow Paved Swales
Lawns Ground Waterways (Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations:Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey-Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.5000 5 0.90 N/A 0.37 0.23
1
2
3
4
5
Sum 5 Computed Tc =0.23
Regional Tc =10.03
User-Entered Tc =5.00
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =9.46 inch/hr Peak Flowrate, Qp =0.253 cfs
Rainfall Intensity at Regional Tc, I =4.67 inch/hr Peak Flowrate, Qp =0.125 cfs
Rainfall Intensity at User-Defined Tc, I =6.33 inch/hr Peak Flowrate, Qp =0.169 cfs
1/16/18
100YR-PB6.xls Page 3
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:Thunderbowl
Catchment ID:PB:6
I.Catchment Hydrologic Data
Catchment ID =PB:6
Area =0.001 Acres
Percent Imperviousness =100.00 %
NRCS Soil Type =C A, B, C, or D
II.Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3
Design Storm Return Period, Tr =100 years (input return period for design storm)
C1 =88.80 (input the value of C1)
C2=10.00 (input the value of C2)
C3=1.052 (input the value of C3)
P1=1.23 inches (input one-hr precipitation--see Sheet "Design Info")
III.Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =0.96
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.90
Overide 5-yr. Runoff Coefficient, C =(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land Heavy Tillage/Short Nearly Grassed Paved Areas &
Type Meadow Field Pasture/Bare Swales/Shallow Paved Swales
Lawns Ground Waterways (Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations:Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey-Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.5000 5 0.90 N/A 0.37 0.23
1
2
3
4
5
Sum 5 Computed Tc =0.23
Regional Tc =10.03
User-Entered Tc =5.00
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =9.46 inch/hr Peak Flowrate, Qp =0.011 cfs
Rainfall Intensity at Regional Tc, I =4.67 inch/hr Peak Flowrate, Qp =0.006 cfs
Rainfall Intensity at User-Defined Tc, I =6.33 inch/hr Peak Flowrate, Qp =0.008 cfs
1/16/18
100YR-PB7.xls Page 3
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:Thunderbowl
Catchment ID:PB:7
I.Catchment Hydrologic Data
Catchment ID =PB:7
Area =0.012 Acres
Percent Imperviousness =0.00 %
NRCS Soil Type =C A, B, C, or D
II.Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3
Design Storm Return Period, Tr =100 years (input return period for design storm)
C1 =88.80 (input the value of C1)
C2=10.00 (input the value of C2)
C3=1.052 (input the value of C3)
P1=1.23 inches (input one-hr precipitation--see Sheet "Design Info")
III.Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =0.50
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.15
Overide 5-yr. Runoff Coefficient, C =(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land Heavy Tillage/Short Nearly Grassed Paved Areas &
Type Meadow Field Pasture/Bare Swales/Shallow Paved Swales
Lawns Ground Waterways (Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations:Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey-Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.5000 5 0.15 N/A 0.08 1.05
1
2
3
4
5
Sum 5 Computed Tc =1.05
Regional Tc =10.03
User-Entered Tc =5.00
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =8.72 inch/hr Peak Flowrate, Qp =0.051 cfs
Rainfall Intensity at Regional Tc, I =4.67 inch/hr Peak Flowrate, Qp =0.027 cfs
Rainfall Intensity at User-Defined Tc, I =6.33 inch/hr Peak Flowrate, Qp =0.037 cfs
1/16/18
100YR-PB8.xls Page 3
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:Thunderbowl
Catchment ID:PB:8
I.Catchment Hydrologic Data
Catchment ID =PB:8
Area =0.004 Acres
Percent Imperviousness =100.00 %
NRCS Soil Type =C A, B, C, or D
II.Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3
Design Storm Return Period, Tr =100 years (input return period for design storm)
C1 =88.80 (input the value of C1)
C2=10.00 (input the value of C2)
C3=1.052 (input the value of C3)
P1=1.23 inches (input one-hr precipitation--see Sheet "Design Info")
III.Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =0.96
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.90
Overide 5-yr. Runoff Coefficient, C =(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land Heavy Tillage/Short Nearly Grassed Paved Areas &
Type Meadow Field Pasture/Bare Swales/Shallow Paved Swales
Lawns Ground Waterways (Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations:Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey-Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.5000 5 0.90 N/A 0.37 0.23
1
2
3
4
5
Sum 5 Computed Tc =0.23
Regional Tc =10.03
User-Entered Tc =5.00
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =9.46 inch/hr Peak Flowrate, Qp =0.032 cfs
Rainfall Intensity at Regional Tc, I =4.67 inch/hr Peak Flowrate, Qp =0.016 cfs
Rainfall Intensity at User-Defined Tc, I =6.33 inch/hr Peak Flowrate, Qp =0.021 cfs
1/16/18
100YR-PB9.xls Page 3
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:Thunderbowl
Catchment ID:PB:9
I.Catchment Hydrologic Data
Catchment ID =PB:9
Area =0.003 Acres
Percent Imperviousness =20.10 %
NRCS Soil Type =C A, B, C, or D
II.Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3
Design Storm Return Period, Tr =100 years (input return period for design storm)
C1 =88.80 (input the value of C1)
C2=10.00 (input the value of C2)
C3=1.052 (input the value of C3)
P1=1.23 inches (input one-hr precipitation--see Sheet "Design Info")
III.Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =0.55
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.26
Overide 5-yr. Runoff Coefficient, C =(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land Heavy Tillage/Short Nearly Grassed Paved Areas &
Type Meadow Field Pasture/Bare Swales/Shallow Paved Swales
Lawns Ground Waterways (Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations:Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey-Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.5000 5 0.26 N/A 0.09 0.93
1
2
3
4
5
Sum 5 Computed Tc =0.93
Regional Tc =10.03
User-Entered Tc =5.00
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =8.82 inch/hr Peak Flowrate, Qp =0.015 cfs
Rainfall Intensity at Regional Tc, I =4.67 inch/hr Peak Flowrate, Qp =0.008 cfs
Rainfall Intensity at User-Defined Tc, I =6.33 inch/hr Peak Flowrate, Qp =0.010 cfs
1/16/18
100YR-PB10.xls Page 3
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:Thunderbowl
Catchment ID:PB:10
I.Catchment Hydrologic Data
Catchment ID =PB:10
Area =0.007 Acres
Percent Imperviousness =100.00 %
NRCS Soil Type =C A, B, C, or D
II.Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3
Design Storm Return Period, Tr =100 years (input return period for design storm)
C1 =88.80 (input the value of C1)
C2=10.00 (input the value of C2)
C3=1.052 (input the value of C3)
P1=1.23 inches (input one-hr precipitation--see Sheet "Design Info")
III.Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =0.96
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.90
Overide 5-yr. Runoff Coefficient, C =(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land Heavy Tillage/Short Nearly Grassed Paved Areas &
Type Meadow Field Pasture/Bare Swales/Shallow Paved Swales
Lawns Ground Waterways (Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations:Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey-Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.5000 5 0.90 N/A 0.37 0.23
1
2
3
4
5
Sum 5 Computed Tc =0.23
Regional Tc =10.03
User-Entered Tc =5.00
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =9.46 inch/hr Peak Flowrate, Qp =0.063 cfs
Rainfall Intensity at Regional Tc, I =4.67 inch/hr Peak Flowrate, Qp =0.031 cfs
Rainfall Intensity at User-Defined Tc, I =6.33 inch/hr Peak Flowrate, Qp =0.042 cfs
1/16/18
100YR-PB11.xls Page 3
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:Thunderbowl
Catchment ID:PB:11
I.Catchment Hydrologic Data
Catchment ID =PB:11
Area =0.002 Acres
Percent Imperviousness =100.00 %
NRCS Soil Type =C A, B, C, or D
II.Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3
Design Storm Return Period, Tr =100 years (input return period for design storm)
C1 =88.80 (input the value of C1)
C2=10.00 (input the value of C2)
C3=1.052 (input the value of C3)
P1=1.23 inches (input one-hr precipitation--see Sheet "Design Info")
III.Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =0.96
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.90
Overide 5-yr. Runoff Coefficient, C =(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land Heavy Tillage/Short Nearly Grassed Paved Areas &
Type Meadow Field Pasture/Bare Swales/Shallow Paved Swales
Lawns Ground Waterways (Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations:Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey-Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.5000 5 0.90 N/A 0.37 0.23
1
2
3
4
5
Sum 5 Computed Tc =0.23
Regional Tc =10.03
User-Entered Tc =5.00
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =9.46 inch/hr Peak Flowrate, Qp =0.018 cfs
Rainfall Intensity at Regional Tc, I =4.67 inch/hr Peak Flowrate, Qp =0.009 cfs
Rainfall Intensity at User-Defined Tc, I =6.33 inch/hr Peak Flowrate, Qp =0.012 cfs
1/16/18
100YR-PB12.xls Page 3
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:Thunderbowl
Catchment ID:PB:12
I.Catchment Hydrologic Data
Catchment ID =PB:12
Area =0.080 Acres
Percent Imperviousness =81.60 %
NRCS Soil Type =C A, B, C, or D
II.Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3
Design Storm Return Period, Tr =100 years (input return period for design storm)
C1 =88.80 (input the value of C1)
C2=10.00 (input the value of C2)
C3=1.052 (input the value of C3)
P1=1.23 inches (input one-hr precipitation--see Sheet "Design Info")
III.Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =0.76
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.64
Overide 5-yr. Runoff Coefficient, C =(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land Heavy Tillage/Short Nearly Grassed Paved Areas &
Type Meadow Field Pasture/Bare Swales/Shallow Paved Swales
Lawns Ground Waterways (Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations:Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey-Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.5000 5 0.64 N/A 0.16 0.51
1
2
3
4
5
Sum 5 Computed Tc =0.51
Regional Tc =10.03
User-Entered Tc =5.00
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =9.20 inch/hr Peak Flowrate, Qp =0.556 cfs
Rainfall Intensity at Regional Tc, I =4.67 inch/hr Peak Flowrate, Qp =0.282 cfs
Rainfall Intensity at User-Defined Tc, I =6.33 inch/hr Peak Flowrate, Qp =0.383 cfs
1/16/18
100YR-PB13.xls Page 3
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:Thunderbowl
Catchment ID:PB:13
I.Catchment Hydrologic Data
Catchment ID =PB:13
Area =0.015 Acres
Percent Imperviousness =0.00 %
NRCS Soil Type =C A, B, C, or D
II.Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3
Design Storm Return Period, Tr =100 years (input return period for design storm)
C1 =88.80 (input the value of C1)
C2=10.00 (input the value of C2)
C3=1.052 (input the value of C3)
P1=1.23 inches (input one-hr precipitation--see Sheet "Design Info")
III.Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =0.50
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.15
Overide 5-yr. Runoff Coefficient, C =(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land Heavy Tillage/Short Nearly Grassed Paved Areas &
Type Meadow Field Pasture/Bare Swales/Shallow Paved Swales
Lawns Ground Waterways (Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations:Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey-Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.5000 5 0.15 N/A 0.08 1.05
1
2
3
4
5
Sum 5 Computed Tc =1.05
Regional Tc =10.03
User-Entered Tc =5.00
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =8.72 inch/hr Peak Flowrate, Qp =0.065 cfs
Rainfall Intensity at Regional Tc, I =4.67 inch/hr Peak Flowrate, Qp =0.035 cfs
Rainfall Intensity at User-Defined Tc, I =6.33 inch/hr Peak Flowrate, Qp =0.047 cfs
1/16/18
5YR-PB1.1.xls Page 3
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:Thunderbowl
Catchment ID:PB:1.1
I.Catchment Hydrologic Data
Catchment ID =PB:1.1
Area =0.087 Acres
Percent Imperviousness =3.20 %
NRCS Soil Type =C A, B, C, or D
II.Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3
Design Storm Return Period, Tr =5 years (input return period for design storm)
C1 =88.80 (input the value of C1)
C2=10.00 (input the value of C2)
C3=1.052 (input the value of C3)
P1=0.64 inches (input one-hr precipitation--see Sheet "Design Info")
III.Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =0.17
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.17
Overide 5-yr. Runoff Coefficient, C =(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land Heavy Tillage/Short Nearly Grassed Paved Areas &
Type Meadow Field Pasture/Bare Swales/Shallow Paved Swales
Lawns Ground Waterways (Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations:Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey-Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.1400 113 0.17 N/A 0.25 7.46
1
2
3
4
5
Sum 113 Computed Tc =7.46
Regional Tc =10.63
User-Entered Tc =7.46
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =2.81 inch/hr Peak Flowrate, Qp =0.042 cfs
Rainfall Intensity at Regional Tc, I =2.35 inch/hr Peak Flowrate, Qp =0.035 cfs
Rainfall Intensity at User-Defined Tc, I =2.81 inch/hr Peak Flowrate, Qp =0.042 cfs
1/16/18
5YR-PB1.2.xls Page 3
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:Thunderbowl
Catchment ID:PB:1.2
I.Catchment Hydrologic Data
Catchment ID =PB:1.2
Area =0.033 Acres
Percent Imperviousness =5.20 %
NRCS Soil Type =C A, B, C, or D
II.Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3
Design Storm Return Period, Tr =5 years (input return period for design storm)
C1 =88.80 (input the value of C1)
C2=10.00 (input the value of C2)
C3=1.052 (input the value of C3)
P1=0.64 inches (input one-hr precipitation--see Sheet "Design Info")
III.Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =0.18
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.18
Overide 5-yr. Runoff Coefficient, C =(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land Heavy Tillage/Short Nearly Grassed Paved Areas &
Type Meadow Field Pasture/Bare Swales/Shallow Paved Swales
Lawns Ground Waterways (Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations:Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey-Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.1600 63 0.18 N/A 0.20 5.26
1
2
3
4
5
Sum 63 Computed Tc =5.26
Regional Tc =10.35
User-Entered Tc =5.26
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =3.23 inch/hr Peak Flowrate, Qp =0.020 cfs
Rainfall Intensity at Regional Tc, I =2.39 inch/hr Peak Flowrate, Qp =0.014 cfs
Rainfall Intensity at User-Defined Tc, I =3.23 inch/hr Peak Flowrate, Qp =0.020 cfs
1/16/18
5YR-PB1.3.xls Page 3
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:Thunderbowl
Catchment ID:PB:1.3
I.Catchment Hydrologic Data
Catchment ID =PB:1.3
Area =0.009 Acres
Percent Imperviousness =0.00 %
NRCS Soil Type =C A, B, C, or D
II.Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3
Design Storm Return Period, Tr =5 years (input return period for design storm)
C1 =88.80 (input the value of C1)
C2=10.00 (input the value of C2)
C3=1.052 (input the value of C3)
P1=0.64 inches (input one-hr precipitation--see Sheet "Design Info")
III.Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =0.15
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.15
Overide 5-yr. Runoff Coefficient, C =(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land Heavy Tillage/Short Nearly Grassed Paved Areas &
Type Meadow Field Pasture/Bare Swales/Shallow Paved Swales
Lawns Ground Waterways (Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations:Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey-Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.1900 31 0.15 N/A 0.14 3.61
1
2
3
4
5
Sum 31 Computed Tc =3.61
Regional Tc =10.17
User-Entered Tc =5.00
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =3.65 inch/hr Peak Flowrate, Qp =0.005 cfs
Rainfall Intensity at Regional Tc, I =2.41 inch/hr Peak Flowrate, Qp =0.003 cfs
Rainfall Intensity at User-Defined Tc, I =3.29 inch/hr Peak Flowrate, Qp =0.004 cfs
1/16/18
5YR-PB1.4.xls Page 3
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:Thunderbowl
Catchment ID:PB:1.4
I.Catchment Hydrologic Data
Catchment ID =PB:1.4
Area =0.017 Acres
Percent Imperviousness =2.10 %
NRCS Soil Type =C A, B, C, or D
II.Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3
Design Storm Return Period, Tr =5 years (input return period for design storm)
C1 =88.80 (input the value of C1)
C2=10.00 (input the value of C2)
C3=1.052 (input the value of C3)
P1=0.64 inches (input one-hr precipitation--see Sheet "Design Info")
III.Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =0.16
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.16
Overide 5-yr. Runoff Coefficient, C =(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land Heavy Tillage/Short Nearly Grassed Paved Areas &
Type Meadow Field Pasture/Bare Swales/Shallow Paved Swales
Lawns Ground Waterways (Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations:Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey-Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.2200 46 0.16 N/A 0.19 4.13
1
2
3
4
5
Sum 46 Computed Tc =4.13
Regional Tc =10.26
User-Entered Tc =5.00
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =3.50 inch/hr Peak Flowrate, Qp =0.010 cfs
Rainfall Intensity at Regional Tc, I =2.40 inch/hr Peak Flowrate, Qp =0.007 cfs
Rainfall Intensity at User-Defined Tc, I =3.29 inch/hr Peak Flowrate, Qp =0.009 cfs
1/16/18
5YR-PB1.5.xls Page 3
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:Thunderbowl
Catchment ID:PB:1.5
I.Catchment Hydrologic Data
Catchment ID =PB:1.5
Area =0.031 Acres
Percent Imperviousness =50.00 %
NRCS Soil Type =C A, B, C, or D
II.Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3
Design Storm Return Period, Tr =5 years (input return period for design storm)
C1 =88.80 (input the value of C1)
C2=10.00 (input the value of C2)
C3=1.052 (input the value of C3)
P1=0.64 inches (input one-hr precipitation--see Sheet "Design Info")
III.Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =0.40
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.40
Overide 5-yr. Runoff Coefficient, C =(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land Heavy Tillage/Short Nearly Grassed Paved Areas &
Type Meadow Field Pasture/Bare Swales/Shallow Paved Swales
Lawns Ground Waterways (Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations:Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey-Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.0100 39 0.40 N/A 0.08 7.92
1
2
3
4
5
Sum 39 Computed Tc =7.92
Regional Tc =10.22
User-Entered Tc =7.92
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =2.73 inch/hr Peak Flowrate, Qp =0.034 cfs
Rainfall Intensity at Regional Tc, I =2.40 inch/hr Peak Flowrate, Qp =0.030 cfs
Rainfall Intensity at User-Defined Tc, I =2.73 inch/hr Peak Flowrate, Qp =0.034 cfs
1/16/18
5YR-PB1.6.xls Page 3
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:Thunderbowl
Catchment ID:PB:1.6
I.Catchment Hydrologic Data
Catchment ID =PB:1.6
Area =0.046 Acres
Percent Imperviousness =100.00 %
NRCS Soil Type =C A, B, C, or D
II.Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3
Design Storm Return Period, Tr =5 years (input return period for design storm)
C1 =88.80 (input the value of C1)
C2=10.00 (input the value of C2)
C3=1.052 (input the value of C3)
P1=0.64 inches (input one-hr precipitation--see Sheet "Design Info")
III.Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =0.90
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.90
Overide 5-yr. Runoff Coefficient, C =(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land Heavy Tillage/Short Nearly Grassed Paved Areas &
Type Meadow Field Pasture/Bare Swales/Shallow Paved Swales
Lawns Ground Waterways (Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations:Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey-Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.0200 10 0.90 N/A 0.18 0.93
1
2
3
4
5
Sum 10 Computed Tc =0.93
Regional Tc =10.06
User-Entered Tc =5.00
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =4.59 inch/hr Peak Flowrate, Qp =0.189 cfs
Rainfall Intensity at Regional Tc, I =2.42 inch/hr Peak Flowrate, Qp =0.100 cfs
Rainfall Intensity at User-Defined Tc, I =3.29 inch/hr Peak Flowrate, Qp =0.136 cfs
1/16/18
5YR-PB1.7.xls Page 3
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:Thunderbowl
Catchment ID:PB:1.7
I.Catchment Hydrologic Data
Catchment ID =PB:1.7
Area =0.011 Acres
Percent Imperviousness =0.00 %
NRCS Soil Type =C A, B, C, or D
II.Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3
Design Storm Return Period, Tr =5 years (input return period for design storm)
C1 =88.80 (input the value of C1)
C2=10.00 (input the value of C2)
C3=1.052 (input the value of C3)
P1=0.64 inches (input one-hr precipitation--see Sheet "Design Info")
III.Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =0.15
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.15
Overide 5-yr. Runoff Coefficient, C =(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land Heavy Tillage/Short Nearly Grassed Paved Areas &
Type Meadow Field Pasture/Bare Swales/Shallow Paved Swales
Lawns Ground Waterways (Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations:Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey-Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.3600 25 0.15 N/A 0.16 2.63
1
2
3
4
5
Sum 25 Computed Tc =2.63
Regional Tc =10.14
User-Entered Tc =5.00
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =3.94 inch/hr Peak Flowrate, Qp =0.007 cfs
Rainfall Intensity at Regional Tc, I =2.41 inch/hr Peak Flowrate, Qp =0.004 cfs
Rainfall Intensity at User-Defined Tc, I =3.29 inch/hr Peak Flowrate, Qp =0.005 cfs
1/16/18
5YR-PB1.8.xls Page 3
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:Thunderbowl
Catchment ID:PB:1.8
I.Catchment Hydrologic Data
Catchment ID =PB:1.8
Area =0.016 Acres
Percent Imperviousness =100.00 %
NRCS Soil Type =C A, B, C, or D
II.Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3
Design Storm Return Period, Tr =5 years (input return period for design storm)
C1 =88.80 (input the value of C1)
C2=10.00 (input the value of C2)
C3=1.052 (input the value of C3)
P1=0.64 inches (input one-hr precipitation--see Sheet "Design Info")
III.Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =0.90
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.90
Overide 5-yr. Runoff Coefficient, C =(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land Heavy Tillage/Short Nearly Grassed Paved Areas &
Type Meadow Field Pasture/Bare Swales/Shallow Paved Swales
Lawns Ground Waterways (Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations:Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey-Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.0800 42 0.90 N/A 0.58 1.20
1
2
3
4
5
Sum 42 Computed Tc =1.20
Regional Tc =10.23
User-Entered Tc =5.00
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =4.48 inch/hr Peak Flowrate, Qp =0.064 cfs
Rainfall Intensity at Regional Tc, I =2.40 inch/hr Peak Flowrate, Qp =0.034 cfs
Rainfall Intensity at User-Defined Tc, I =3.29 inch/hr Peak Flowrate, Qp =0.047 cfs
1/16/18
5YR-PB1.9.xls Page 3
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:Thunderbowl
Catchment ID:PB:1.8
I.Catchment Hydrologic Data
Catchment ID =PB:1.8
Area =0.105 Acres
Percent Imperviousness =6.50 %
NRCS Soil Type =C A, B, C, or D
II.Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3
Design Storm Return Period, Tr =5 years (input return period for design storm)
C1 =88.80 (input the value of C1)
C2=10.00 (input the value of C2)
C3=1.052 (input the value of C3)
P1=0.64 inches (input one-hr precipitation--see Sheet "Design Info")
III.Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =0.19
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.19
Overide 5-yr. Runoff Coefficient, C =(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land Heavy Tillage/Short Nearly Grassed Paved Areas &
Type Meadow Field Pasture/Bare Swales/Shallow Paved Swales
Lawns Ground Waterways (Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations:Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey-Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.0700 92 0.19 N/A 0.19 8.29
1
2
3
4
5
Sum 92 Computed Tc =8.29
Regional Tc =10.51
User-Entered Tc =8.29
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =2.67 inch/hr Peak Flowrate, Qp =0.053 cfs
Rainfall Intensity at Regional Tc, I =2.37 inch/hr Peak Flowrate, Qp =0.047 cfs
Rainfall Intensity at User-Defined Tc, I =2.67 inch/hr Peak Flowrate, Qp =0.053 cfs
1/16/18
100YR-PB1.1.xls Page 3
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:Thunderbowl
Catchment ID:PB:1.1
I.Catchment Hydrologic Data
Catchment ID =PB:1.1
Area =0.087 Acres
Percent Imperviousness =3.20 %
NRCS Soil Type =C A, B, C, or D
II.Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3
Design Storm Return Period, Tr =100 years (input return period for design storm)
C1 =88.80 (input the value of C1)
C2=10.00 (input the value of C2)
C3=1.052 (input the value of C3)
P1=1.23 inches (input one-hr precipitation--see Sheet "Design Info")
III.Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =0.51
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.17
Overide 5-yr. Runoff Coefficient, C =(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land Heavy Tillage/Short Nearly Grassed Paved Areas &
Type Meadow Field Pasture/Bare Swales/Shallow Paved Swales
Lawns Ground Waterways (Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations:Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey-Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.1400 113 0.17 N/A 0.25 7.46
1
2
3
4
5
Sum 113 Computed Tc =7.46
Regional Tc =10.63
User-Entered Tc =7.46
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =5.39 inch/hr Peak Flowrate, Qp =0.240 cfs
Rainfall Intensity at Regional Tc, I =4.52 inch/hr Peak Flowrate, Qp =0.201 cfs
Rainfall Intensity at User-Defined Tc, I =5.39 inch/hr Peak Flowrate, Qp =0.240 cfs
1/16/18
100YR-PB1.2.xls Page 3
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:Thunderbowl
Catchment ID:PB:1.2
I.Catchment Hydrologic Data
Catchment ID =PB:1.2
Area =0.033 Acres
Percent Imperviousness =5.20 %
NRCS Soil Type =C A, B, C, or D
II.Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3
Design Storm Return Period, Tr =100 years (input return period for design storm)
C1 =88.80 (input the value of C1)
C2=10.00 (input the value of C2)
C3=1.052 (input the value of C3)
P1=1.23 inches (input one-hr precipitation--see Sheet "Design Info")
III.Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =0.52
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.18
Overide 5-yr. Runoff Coefficient, C =(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land Heavy Tillage/Short Nearly Grassed Paved Areas &
Type Meadow Field Pasture/Bare Swales/Shallow Paved Swales
Lawns Ground Waterways (Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations:Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey-Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.1600 63 0.18 N/A 0.20 5.26
1
2
3
4
5
Sum 63 Computed Tc =5.26
Regional Tc =10.35
User-Entered Tc =5.26
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =6.21 inch/hr Peak Flowrate, Qp =0.106 cfs
Rainfall Intensity at Regional Tc, I =4.59 inch/hr Peak Flowrate, Qp =0.078 cfs
Rainfall Intensity at User-Defined Tc, I =6.21 inch/hr Peak Flowrate, Qp =0.106 cfs
1/16/18
100YR-PB1.3.xls Page 3
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:Thunderbowl
Catchment ID:PB:1.3
I.Catchment Hydrologic Data
Catchment ID =PB:1.3
Area =0.009 Acres
Percent Imperviousness =0.00 %
NRCS Soil Type =C A, B, C, or D
II.Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3
Design Storm Return Period, Tr =100 years (input return period for design storm)
C1 =88.80 (input the value of C1)
C2=10.00 (input the value of C2)
C3=1.052 (input the value of C3)
P1=1.23 inches (input one-hr precipitation--see Sheet "Design Info")
III.Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =0.50
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.15
Overide 5-yr. Runoff Coefficient, C =(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land Heavy Tillage/Short Nearly Grassed Paved Areas &
Type Meadow Field Pasture/Bare Swales/Shallow Paved Swales
Lawns Ground Waterways (Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations:Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey-Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.1900 31 0.15 N/A 0.14 3.61
1
2
3
4
5
Sum 31 Computed Tc =3.61
Regional Tc =10.17
User-Entered Tc =5.00
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =7.01 inch/hr Peak Flowrate, Qp =0.032 cfs
Rainfall Intensity at Regional Tc, I =4.63 inch/hr Peak Flowrate, Qp =0.021 cfs
Rainfall Intensity at User-Defined Tc, I =6.33 inch/hr Peak Flowrate, Qp =0.028 cfs
1/16/18
100YR-PB1.4.xls Page 3
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:Thunderbowl
Catchment ID:PB:1.4
I.Catchment Hydrologic Data
Catchment ID =PB:1.4
Area =0.017 Acres
Percent Imperviousness =2.10 %
NRCS Soil Type =C A, B, C, or D
II.Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3
Design Storm Return Period, Tr =100 years (input return period for design storm)
C1 =88.80 (input the value of C1)
C2=10.00 (input the value of C2)
C3=1.052 (input the value of C3)
P1=1.23 inches (input one-hr precipitation--see Sheet "Design Info")
III.Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =0.51
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.16
Overide 5-yr. Runoff Coefficient, C =(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land Heavy Tillage/Short Nearly Grassed Paved Areas &
Type Meadow Field Pasture/Bare Swales/Shallow Paved Swales
Lawns Ground Waterways (Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations:Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey-Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.2200 46 0.16 N/A 0.19 4.13
1
2
3
4
5
Sum 46 Computed Tc =4.13
Regional Tc =10.26
User-Entered Tc =5.00
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =6.74 inch/hr Peak Flowrate, Qp =0.058 cfs
Rainfall Intensity at Regional Tc, I =4.61 inch/hr Peak Flowrate, Qp =0.040 cfs
Rainfall Intensity at User-Defined Tc, I =6.33 inch/hr Peak Flowrate, Qp =0.055 cfs
1/16/18
100YR-PB1.5.xls Page 3
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:Thunderbowl
Catchment ID:PB:1.5
I.Catchment Hydrologic Data
Catchment ID =PB:1.5
Area =0.031 Acres
Percent Imperviousness =50.00 %
NRCS Soil Type =C A, B, C, or D
II.Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3
Design Storm Return Period, Tr =100 years (input return period for design storm)
C1 =88.80 (input the value of C1)
C2=10.00 (input the value of C2)
C3=1.052 (input the value of C3)
P1=1.23 inches (input one-hr precipitation--see Sheet "Design Info")
III.Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =0.60
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.40
Overide 5-yr. Runoff Coefficient, C =(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land Heavy Tillage/Short Nearly Grassed Paved Areas &
Type Meadow Field Pasture/Bare Swales/Shallow Paved Swales
Lawns Ground Waterways (Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations:Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey-Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.0100 39 0.40 N/A 0.08 7.92
1
2
3
4
5
Sum 39 Computed Tc =7.92
Regional Tc =10.22
User-Entered Tc =7.92
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =5.25 inch/hr Peak Flowrate, Qp =0.098 cfs
Rainfall Intensity at Regional Tc, I =4.62 inch/hr Peak Flowrate, Qp =0.086 cfs
Rainfall Intensity at User-Defined Tc, I =5.25 inch/hr Peak Flowrate, Qp =0.098 cfs
1/16/18
100YR-PB1.6.xls Page 3
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:Thunderbowl
Catchment ID:PB:1.6
I.Catchment Hydrologic Data
Catchment ID =PB:1.6
Area =0.046 Acres
Percent Imperviousness =100.00 %
NRCS Soil Type =C A, B, C, or D
II.Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3
Design Storm Return Period, Tr =100 years (input return period for design storm)
C1 =88.80 (input the value of C1)
C2=10.00 (input the value of C2)
C3=1.052 (input the value of C3)
P1=1.23 inches (input one-hr precipitation--see Sheet "Design Info")
III.Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =0.96
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.90
Overide 5-yr. Runoff Coefficient, C =(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land Heavy Tillage/Short Nearly Grassed Paved Areas &
Type Meadow Field Pasture/Bare Swales/Shallow Paved Swales
Lawns Ground Waterways (Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations:Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey-Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.0200 10 0.90 N/A 0.18 0.93
1
2
3
4
5
Sum 10 Computed Tc =0.93
Regional Tc =10.06
User-Entered Tc =5.00
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =8.82 inch/hr Peak Flowrate, Qp =0.388 cfs
Rainfall Intensity at Regional Tc, I =4.66 inch/hr Peak Flowrate, Qp =0.205 cfs
Rainfall Intensity at User-Defined Tc, I =6.33 inch/hr Peak Flowrate, Qp =0.278 cfs
1/16/18
100YR-PB1.7.xls Page 3
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:Thunderbowl
Catchment ID:PB:1.7
I.Catchment Hydrologic Data
Catchment ID =PB:1.7
Area =0.011 Acres
Percent Imperviousness =0.00 %
NRCS Soil Type =C A, B, C, or D
II.Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3
Design Storm Return Period, Tr =100 years (input return period for design storm)
C1 =88.80 (input the value of C1)
C2=10.00 (input the value of C2)
C3=1.052 (input the value of C3)
P1=1.23 inches (input one-hr precipitation--see Sheet "Design Info")
III.Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =0.50
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.15
Overide 5-yr. Runoff Coefficient, C =(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land Heavy Tillage/Short Nearly Grassed Paved Areas &
Type Meadow Field Pasture/Bare Swales/Shallow Paved Swales
Lawns Ground Waterways (Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations:Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey-Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.3600 25 0.15 N/A 0.16 2.63
1
2
3
4
5
Sum 25 Computed Tc =2.63
Regional Tc =10.14
User-Entered Tc =5.00
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =7.58 inch/hr Peak Flowrate, Qp =0.042 cfs
Rainfall Intensity at Regional Tc, I =4.64 inch/hr Peak Flowrate, Qp =0.026 cfs
Rainfall Intensity at User-Defined Tc, I =6.33 inch/hr Peak Flowrate, Qp =0.035 cfs
1/16/18
100YR-PB1.8.xls Page 3
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:Thunderbowl
Catchment ID:PB:1.8
I.Catchment Hydrologic Data
Catchment ID =PB:1.8
Area =0.016 Acres
Percent Imperviousness =100.00 %
NRCS Soil Type =C A, B, C, or D
II.Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3
Design Storm Return Period, Tr =100 years (input return period for design storm)
C1 =88.80 (input the value of C1)
C2=10.00 (input the value of C2)
C3=1.052 (input the value of C3)
P1=1.23 inches (input one-hr precipitation--see Sheet "Design Info")
III.Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =0.96
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.90
Overide 5-yr. Runoff Coefficient, C =(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land Heavy Tillage/Short Nearly Grassed Paved Areas &
Type Meadow Field Pasture/Bare Swales/Shallow Paved Swales
Lawns Ground Waterways (Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations:Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey-Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.0800 42 0.90 N/A 0.58 1.20
1
2
3
4
5
Sum 42 Computed Tc =1.20
Regional Tc =10.23
User-Entered Tc =5.00
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =8.60 inch/hr Peak Flowrate, Qp =0.132 cfs
Rainfall Intensity at Regional Tc, I =4.62 inch/hr Peak Flowrate, Qp =0.071 cfs
Rainfall Intensity at User-Defined Tc, I =6.33 inch/hr Peak Flowrate, Qp =0.097 cfs
1/16/18
100YR-PB1.9.xls Page 3
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:Thunderbowl
Catchment ID:PB:1.8
I.Catchment Hydrologic Data
Catchment ID =PB:1.8
Area =0.105 Acres
Percent Imperviousness =6.50 %
NRCS Soil Type =C A, B, C, or D
II.Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3
Design Storm Return Period, Tr =100 years (input return period for design storm)
C1 =88.80 (input the value of C1)
C2=10.00 (input the value of C2)
C3=1.052 (input the value of C3)
P1=1.23 inches (input one-hr precipitation--see Sheet "Design Info")
III.Analysis of Flow Time (Time of Concentration) for a Catchment
Runoff Coefficient, C =0.52
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.19
Overide 5-yr. Runoff Coefficient, C =(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.)
Illustration
NRCS Land Heavy Tillage/Short Nearly Grassed Paved Areas &
Type Meadow Field Pasture/Bare Swales/Shallow Paved Swales
Lawns Ground Waterways (Sheet Flow)
Conveyance 2.5 5 7 10 15 20
Calculations:Reach Slope Length 5-yr NRCS Flow Flow
ID S L Runoff Convey-Velocity Time
Coeff ance V Tf
ft/ft ft C-5 fps minutes
input input output input output output
Overland 0.0700 92 0.19 N/A 0.19 8.29
1
2
3
4
5
Sum 92 Computed Tc =8.29
Regional Tc =10.51
User-Entered Tc =8.29
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =5.13 inch/hr Peak Flowrate, Qp =0.281 cfs
Rainfall Intensity at Regional Tc, I =4.55 inch/hr Peak Flowrate, Qp =0.249 cfs
Rainfall Intensity at User-Defined Tc, I =5.13 inch/hr Peak Flowrate, Qp =0.281 cfs
1/16/18
5
Appendix E--Hydraulic Calculations
1/16/18
Weir Report
Hydraflow Express Extension for Autodesk® AutoCAD® Civil 3D® by Autodesk, Inc.Thursday, Jan 11 2018
<Name>
Rectangular Weir
Crest = Sharp
Bottom Length (ft) = 1.06
Total Depth (ft) = 0.57
Calculations
Weir Coeff. Cw = 3.33
Compute by: Known Q
Known Q (cfs) = 1.48
Highlighted
Depth (ft) = 0.56
Q (cfs) = 1.480
Area (sqft) = 0.59
Velocity (ft/s) = 2.49
Top Width (ft) = 1.06
0 .5 1 1.5 2 2.5
Depth (ft)Depth (ft)<Name>
-0.50 -0.50
0.00 0.00
0.50 0.50
1.00 1.00
Length (ft)Weir W.S.
1/16/18
Channel Report
Hydraflow Express Extension for Autodesk® AutoCAD® Civil 3D® by Autodesk, Inc.Wednesday, Jan 10 2018
Pipe A - 6 in @ 0.76%
Circular
Diameter (ft) = 0.50
Invert Elev (ft) = 100.00
Slope (%) = 0.76
N-Value = 0.012
Calculations
Compute by: Q vs Depth
No. Increments = 10
Highlighted
Depth (ft) = 0.40
Q (cfs) = 0.518
Area (sqft) = 0.17
Velocity (ft/s) = 3.07
Wetted Perim (ft) = 1.11
Crit Depth, Yc (ft) = 0.37
Top Width (ft) = 0.40
EGL (ft) = 0.55
0 1
Elev (ft)Section
99.75
100.00
100.25
100.50
100.75
101.00
Reach (ft)
1/16/18
Channel Report
Hydraflow Express Extension for Autodesk® AutoCAD® Civil 3D® by Autodesk, Inc.Thursday, Jan 11 2018
6-in @ 4%
Circular
Diameter (ft) = 0.50
Invert Elev (ft) = 100.00
Slope (%) = 4.00
N-Value = 0.012
Calculations
Compute by: Q vs Depth
No. Increments = 10
Highlighted
Depth (ft) = 0.40
Q (cfs) = 1.188
Area (sqft) = 0.17
Velocity (ft/s) = 7.05
Wetted Perim (ft) = 1.11
Crit Depth, Yc (ft) = 0.49
Top Width (ft) = 0.40
EGL (ft) = 1.17
0 1
Elev (ft)Section
99.75
100.00
100.25
100.50
100.75
101.00
Reach (ft)
1/16/18
Channel Report
Hydraflow Express Extension for Autodesk® AutoCAD® Civil 3D® by Autodesk, Inc.Wednesday, Jan 10 2018
Pipe A - 10 in @ 0.76%
Circular
Diameter (ft) = 0.83
Invert Elev (ft) = 100.00
Slope (%) = 0.76
N-Value = 0.012
Calculations
Compute by: Q vs Depth
No. Increments = 10
Highlighted
Depth (ft) = 0.66
Q (cfs) = 2.001
Area (sqft) = 0.46
Velocity (ft/s) = 4.31
Wetted Perim (ft) = 1.84
Crit Depth, Yc (ft) = 0.64
Top Width (ft) = 0.66
EGL (ft) = 0.95
0 1
Elev (ft)Section
99.75
100.00
100.25
100.50
100.75
101.00
Reach (ft)
1/16/18
Channel Report
Hydraflow Express Extension for Autodesk® AutoCAD® Civil 3D® by Autodesk, Inc.Wednesday, Jan 10 2018
Pipe A - Peak Discharge
Circular
Diameter (ft) = 0.50
Invert Elev (ft) = 100.00
Slope (%) = 0.76
N-Value = 0.012
Calculations
Compute by: Known Q
Known Q (cfs) = 0.19
Highlighted
Depth (ft) = 0.21
Q (cfs) = 0.194
Area (sqft) = 0.08
Velocity (ft/s) = 2.46
Wetted Perim (ft) = 0.71
Crit Depth, Yc (ft) = 0.22
Top Width (ft) = 0.49
EGL (ft) = 0.30
0 1
Elev (ft)Section
99.75
100.00
100.25
100.50
100.75
101.00
Reach (ft)
1/16/18
Channel Report
Hydraflow Express Extension for Autodesk® AutoCAD® Civil 3D® by Autodesk, Inc.Wednesday, Jan 10 2018
Pipe B - 10 in @ 0.49%
Circular
Diameter (ft) = 0.83
Invert Elev (ft) = 100.00
Slope (%) = 0.50
N-Value = 0.012
Calculations
Compute by: Q vs Depth
No. Increments = 10
Highlighted
Depth (ft) = 0.66
Q (cfs) = 1.623
Area (sqft) = 0.46
Velocity (ft/s) = 3.50
Wetted Perim (ft) = 1.84
Crit Depth, Yc (ft) = 0.58
Top Width (ft) = 0.66
EGL (ft) = 0.85
0 1
Elev (ft)Section
99.75
100.00
100.25
100.50
100.75
101.00
Reach (ft)
1/16/18
Channel Report
Hydraflow Express Extension for Autodesk® AutoCAD® Civil 3D® by Autodesk, Inc.Wednesday, Jan 10 2018
Pipe B - Peak Discharge
Circular
Diameter (ft) = 0.83
Invert Elev (ft) = 100.00
Slope (%) = 0.49
N-Value = 0.012
Calculations
Compute by: Known Q
Known Q (cfs) = 1.44
Highlighted
Depth (ft) = 0.61
Q (cfs) = 1.440
Area (sqft) = 0.43
Velocity (ft/s) = 3.38
Wetted Perim (ft) = 1.71
Crit Depth, Yc (ft) = 0.54
Top Width (ft) = 0.73
EGL (ft) = 0.79
0 1
Elev (ft)Section
99.75
100.00
100.25
100.50
100.75
101.00
Reach (ft)
1/16/18
6
Appendix F—Detention Calculations
1/16/18
Project:
Basin ID:
Design Information (Input):Design Information (Input):
Catchment Drainage Imperviousness Ia =26.83 percent Catchment Drainage Imperviousness Ia =26.83 percent
Catchment Drainage Area A =0.693 acres Catchment Drainage Area A =0.693 acres
Predevelopment NRCS Soil Group Type =C A, B, C, or D Predevelopment NRCS Soil Group Type =C A, B, C, or D
Return Period for Detention Control T =5 years (2, 5, 10, 25, 50, or 100)Return Period for Detention Control T =100 years (2, 5, 10, 25, 50, or 100)
Time of Concentration of Watershed Tc =5.00 minutes Time of Concentration of Watershed Tc =5.00 minutes
Allowable Unit Release Rate q =0.335 cfs/acre Allowable Unit Release Rate q =2.141 cfs/acre
One-hour Precipitation P1 =0.64 inches One-hour Precipitation P1 =1.23 inches
Design Rainfall IDF Formula i = C1* P1/(C2+Tc)^C3 Design Rainfall IDF Formula i = C1* P1/(C2+Tc)^C3
Coefficient One C1 =88.80 Coefficient One C1 =88.80
Coefficient Two C2 =10 Coefficient Two C2 =10
Coefficient Three C3 =1.052 Coefficient Three C3 =1.052
Determination of Average Outflow from the Basin (Calculated):Determination of Average Outflow from the Basin (Calculated):
Runoff Coefficient C =0.29 Runoff Coefficient C =0.56
Inflow Peak Runoff Qp-in =0.661 cfs Inflow Peak Runoff Qp-in =2.45 cfs
Allowable Peak Outflow Rate Qp-out =0.232 cfs Allowable Peak Outflow Rate Qp-out =1.484 cfs
Mod. FAA Minor Storage Volume = 210 cubic feet Mod. FAA Major Storage Volume = 425 cubic feet
Mod. FAA Minor Storage Volume = 0.005 acre-ft Mod. FAA Major Storage Volume = 0.010 acre-ft
1 <- Enter Rainfall Duration Incremental Increase Value Here (e.g. 5 for 5-Minutes)
Rainfall Rainfall Inflow Adjustment Average Outflow Storage Rainfall Rainfall Inflow Adjustment Average Outflow Storage
Duration Intensity Volume Factor Outflow Volume Volume Duration Intensity Volume Factor Outflow Volume Volume
minutes inches / hr acre-feet "m"cfs acre-feet acre-feet minutes inches / hr acre-feet "m"cfs acre-feet acre-feet
(input)(output)(output)(output)(output)(output)(output)(input)(output)(output)(output)(output)(output)(output)
0 0.00 0.000 0.00 0.00 0.000 0.000 0 0.00 0.000 0.00 0.00 0.000 0.000
1 4.56 0.001 1.00 0.23 0.000 0.001 1 8.77 0.005 1.00 1.48 0.002 0.003
2 4.16 0.002 1.00 0.23 0.001 0.002 2 8.00 0.009 1.00 1.48 0.004 0.004
3 3.83 0.003 1.00 0.23 0.001 0.002 3 7.35 0.012 1.00 1.48 0.006 0.006
4 3.54 0.004 1.00 0.23 0.001 0.003 4 6.80 0.015 1.00 1.48 0.008 0.006
5 3.29 0.005 1.00 0.23 0.002 0.003 5 6.33 0.017 1.00 1.48 0.010 0.007
6 3.08 0.005 0.92 0.21 0.002 0.003 6 5.91 0.019 0.92 1.36 0.011 0.008
7 2.89 0.006 0.86 0.20 0.002 0.004 7 5.54 0.021 0.86 1.27 0.012 0.008
8 2.72 0.006 0.81 0.19 0.002 0.004 8 5.22 0.022 0.81 1.21 0.013 0.009
9 2.57 0.006 0.78 0.18 0.002 0.004 9 4.93 0.024 0.78 1.15 0.014 0.009
10 2.43 0.007 0.75 0.17 0.002 0.004 10 4.67 0.025 0.75 1.11 0.015 0.010
11 2.31 0.007 0.73 0.17 0.003 0.004 11 4.44 0.026 0.73 1.08 0.016 0.010
12 2.20 0.007 0.71 0.16 0.003 0.005 12 4.23 0.027 0.71 1.05 0.017 0.010
13 2.10 0.008 0.69 0.16 0.003 0.005 13 4.03 0.028 0.69 1.03 0.018 0.010
14 2.01 0.008 0.68 0.16 0.003 0.005 14 3.86 0.029 0.68 1.01 0.019 0.009
15 1.92 0.008 0.67 0.15 0.003 0.005 15 3.70 0.030 0.67 0.99 0.020 0.009
16 1.85 0.008 0.66 0.15 0.003 0.005 16 3.55 0.030 0.66 0.97 0.021 0.009
17 1.77 0.008 0.65 0.15 0.004 0.005 17 3.41 0.031 0.65 0.96 0.022 0.008
18 1.71 0.009 0.64 0.15 0.004 0.005 18 3.28 0.032 0.64 0.95 0.024 0.008
19 1.64 0.009 0.63 0.15 0.004 0.005 19 3.16 0.032 0.63 0.94 0.025 0.008
20 1.59 0.009 0.63 0.14 0.004 0.005 20 3.05 0.033 0.63 0.93 0.026 0.007
21 1.53 0.009 0.62 0.14 0.004 0.005 21 2.95 0.033 0.62 0.92 0.027 0.007
22 1.48 0.009 0.61 0.14 0.004 0.005 22 2.85 0.034 0.61 0.91 0.028 0.006
23 1.44 0.009 0.61 0.14 0.004 0.005 23 2.76 0.034 0.61 0.90 0.029 0.005
24 1.39 0.009 0.60 0.14 0.005 0.005 24 2.67 0.034 0.60 0.90 0.030 0.005
25 1.35 0.009 0.60 0.14 0.005 0.005 25 2.59 0.035 0.60 0.89 0.031 0.004
26 1.31 0.009 0.60 0.14 0.005 0.004 26 2.52 0.035 0.60 0.88 0.032 0.003
27 1.27 0.010 0.59 0.14 0.005 0.004 27 2.45 0.035 0.59 0.88 0.033 0.003
28 1.24 0.010 0.59 0.14 0.005 0.004 28 2.38 0.036 0.59 0.87 0.034 0.002
29 1.20 0.010 0.59 0.14 0.005 0.004 29 2.31 0.036 0.59 0.87 0.035 0.001
30 1.17 0.010 0.58 0.14 0.006 0.004 30 2.25 0.036 0.58 0.87 0.036 0.000
31 1.14 0.010 0.58 0.13 0.006 0.004 31 2.20 0.036 0.58 0.86 0.037 0.000
32 1.11 0.010 0.58 0.13 0.006 0.004 32 2.14 0.037 0.58 0.86 0.038 -0.001
33 1.09 0.010 0.58 0.13 0.006 0.004 33 2.09 0.037 0.58 0.85 0.039 -0.002
34 1.06 0.010 0.57 0.13 0.006 0.004 34 2.04 0.037 0.57 0.85 0.040 -0.003
35 1.04 0.010 0.57 0.13 0.006 0.004 35 1.99 0.037 0.57 0.85 0.041 -0.004
36 1.01 0.010 0.57 0.13 0.007 0.004 36 1.95 0.037 0.57 0.85 0.042 -0.004
37 0.99 0.010 0.57 0.13 0.007 0.003 37 1.90 0.038 0.57 0.84 0.043 -0.005
38 0.97 0.010 0.57 0.13 0.007 0.003 38 1.86 0.038 0.57 0.84 0.044 -0.006
39 0.95 0.010 0.56 0.13 0.007 0.003 39 1.82 0.038 0.56 0.84 0.045 -0.007
40 0.93 0.010 0.56 0.13 0.007 0.003 40 1.78 0.038 0.56 0.83 0.046 -0.008
41 0.91 0.010 0.56 0.13 0.007 0.003 41 1.75 0.038 0.56 0.83 0.047 -0.009
42 0.89 0.010 0.56 0.13 0.008 0.003 42 1.71 0.038 0.56 0.83 0.048 -0.010
43 0.87 0.010 0.56 0.13 0.008 0.003 43 1.68 0.039 0.56 0.83 0.049 -0.011
44 0.86 0.010 0.56 0.13 0.008 0.003 44 1.64 0.039 0.56 0.83 0.050 -0.011
45 0.84 0.010 0.56 0.13 0.008 0.002 45 1.61 0.039 0.56 0.82 0.051 -0.012
46 0.82 0.010 0.55 0.13 0.008 0.002 46 1.58 0.039 0.55 0.82 0.052 -0.013
47 0.81 0.011 0.55 0.13 0.008 0.002 47 1.55 0.039 0.55 0.82 0.053 -0.014
48 0.79 0.011 0.55 0.13 0.008 0.002 48 1.52 0.039 0.55 0.82 0.054 -0.015
49 0.78 0.011 0.55 0.13 0.009 0.002 49 1.50 0.039 0.55 0.82 0.055 -0.016
50 0.77 0.011 0.55 0.13 0.009 0.002 50 1.47 0.039 0.55 0.82 0.056 -0.017
51 0.75 0.011 0.55 0.13 0.009 0.002 51 1.45 0.039 0.55 0.81 0.057 -0.018
52 0.74 0.011 0.55 0.13 0.009 0.002 52 1.42 0.040 0.55 0.81 0.058 -0.019
53 0.73 0.011 0.55 0.13 0.009 0.001 53 1.40 0.040 0.55 0.81 0.059 -0.020
54 0.72 0.011 0.55 0.13 0.009 0.001 54 1.37 0.040 0.55 0.81 0.060 -0.021
55 0.70 0.011 0.55 0.13 0.010 0.001 55 1.35 0.040 0.55 0.81 0.061 -0.022
56 0.69 0.011 0.54 0.13 0.010 0.001 56 1.33 0.040 0.54 0.81 0.062 -0.023
57 0.68 0.011 0.54 0.13 0.010 0.001 57 1.31 0.040 0.54 0.81 0.063 -0.023
58 0.67 0.011 0.54 0.13 0.010 0.001 58 1.29 0.040 0.54 0.81 0.064 -0.024
59 0.66 0.011 0.54 0.13 0.010 0.001 59 1.27 0.040 0.54 0.80 0.065 -0.025
60 0.65 0.011 0.54 0.13 0.010 0.000 60 1.25 0.040 0.54 0.80 0.066 -0.026
Mod. FAA Minor Storage Volume (cubic ft.) =210 Mod. FAA Major Storage Volume (cubic ft.) =425
Mod. FAA Minor Storage Volume (acre-ft.) =0.0048 Mod. FAA Major Storage Volume (acre-ft.) =0.0098
Determination of MAJOR Detention Volume Using Modified FAA Method
(For catchments less than 160 acres only. For larger catchments, use hydrograph routing method)
(NOTE: for catchments larger than 90 acres, CUHP hydrograph and routing are recommended)
UDFCD DETENTION BASIN VOLUME ESTIMATING WORKBOOK Version 2.34, Released November 2013
Determination of MINOR Detention Volume Using Modified FAA Method
DETENTION VOLUME BY THE MODIFIED FAA METHOD
Thunderbowl
Site
FAA.xls, Modified FAA 1/11/2018, 9:05 PM
1/16/18
Project:
Basin ID:
UDFCD DETENTION BASIN VOLUME ESTIMATING WORKBOOK Version 2.34, Released November 2013
DETENTION VOLUME BY THE MODIFIED FAA METHOD
Thunderbowl
Site
0
0.01
0.02
0.03
0.04
0.05
0.06
0.07
0 10 20 30 40 50 60 70Volume (acre-feet)Duration (Minutes)
Inflow and Outflow Volumes vs. Rainfall Duration
Minor Storm Inflow Volume Minor Storm Outflow Volume Minor Storm Storage Volume Major Storm Inflow Volume Major Storm Outflow Volume Major Storm Storage Volume
FAA.xls, Modified FAA 1/11/2018, 9:05 PM
1/16/18