HomeMy WebLinkAboutFile Documents.108 Maple Ln.0035.2017 (10).ARBK
Grading and Drainage Report
Prepared for
LESLIE CURLEY
108 Maple Lane, Aspen
P.O. Box 575
Woody Creek, Colorado 81656
970-309-7130
Prepared By
Josh Rice, P.E.
Revised August 30, 2017
Revised June 15, 2017
Revised May 31, 2017
February 02, 2017
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i
I hereby affirm that this report and the accompanying plans for the drainage improvements of Lot 108,
Smuggler Mobile Home Park Subdivision, Aspen 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.
8/30/2017
9/1/17
Reviewed by Engineering
09/14/2017 2:46:16 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.
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 A .......................................................................................................................................... 4
2.3.2 Historical Basin B .......................................................................................................................................... 4
2.3.3 Basin A .......................................................................................................................................................... 5
2.3.4 Basin B .......................................................................................................................................................... 5
2.3.5 Basin B-1 ....................................................................................................................................................... 5
2.3.6 Basin C .......................................................................................................................................................... 5
2.3.7 Basin D.......................................................................................................................................................... 5
2.3.8 Basin E .......................................................................................................................................................... 5
2.3.9 Basin F .......................................................................................................................................................... 5
2.3.10 Basin G ..................................................................................................................................................... 5
2.3.11 Basin H ..................................................................................................................................................... 5
3. STORMWATER BMPS AND ROUTING ......................................................................................... 6
3.1 General ..................................................................................................................................................... 7
3.1.1 Pervious Paver .............................................................................................................................................. 7
3.1.2 Gravel Drains ................................................................................................................................................ 8
3.1.3 24-hr Drain Time Calculation ....................................................................................................................... 9
3.1.4 Operation and maintenance ...................................................................................................................... 10
APPENDIX A--NRCS SOILS REPORT ................................................................................................. 1
APPENDIX B--FEMA FIRM MAP ......................................................................................................... 2
APPENDIX C--PLAN SET ....................................................................................................................... 3
APPENDIX D--HYDROLOGIC CALCULATIONS ............................................................................... 4
APPENDIX E—DETENTION ................................................................................................................. 5
APPENDIX F—MCLAUGHLIN REPORT ............................................................................................ 6
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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 the single family property known as 108
Maple Lane, Aspen, Colorado, 81611 (the “Site”). The Site is located in an area without a regional deten-
tion facility and therefore, facilities providing water quality capture volume and retention have been de-
signed in this report and the associated plan.
2. General Site Description
2.1 Existing Condition
The property, was platted as lot 108 Smuggler Park. Based on the topographical improvement survey, the
lot area is +/- 0.056 acres (approximately 2451 square feet).
The Site is located in the Smuggler Mobile Home Park and overlooks the Roaring Fork River to the west,
and Smuggler Mountain to the north east (see Figure 1). The Site generally slopes from northeast to south-
west at approximately two (2) percent. The soils are described by the NRCS as, “Uracca, moist-Mergel
complex, 6 to 12 percent slopes” (see Appendix A). The hydrologic soil group is “B.” The lot is currently
occupied by a manufactured home.
Figure 1. 108 Maple Lane, 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 of the Roaring Fork River. The Site is located within Zone X, as shown and described by FEMA (see
FIRM Map, Appendix B.)
The site and the surrounding drainage basin was the subject of a City of Aspen stormwater master plan
entitled “Smuggle/Hunter Surface Drainage Master Plan.”
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The only noteworthy adjacent basin is runoff traveling down Maple Lane. Runoff from Maple Lane is
carried in curb and gutter. McLaughlin Water Engineering wrote a drainage report in 2001 that concluded
that (see Appendix F) Maple Lane should adequately handle all storm events. Based on this report, WCE
did not route any offsite flows through the property.
2.2 Proposed Condition
A new single family home will be constructed on the lot.
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 generally flat area. 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
Basins A through H 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
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. Two basins were delineated: “Hist-A” and “Hist-B.”
Table 1. Basin Information
BASIN
NO.
TOTAL
BASIN
AREA
(ACRES)
IMPERV.
AREA
(ACRES)
%
IMPERV
RUNOFF
COEF.
5YR
RUNOFF
COEF.
100YR
FLOW
PATH
LENGT
H (FT)
FLOW
PATH
SLOPE
(FT/FT)
PEAK
FLOW
5YR
(CFS)
PEAK
FLOW
100YR
(CFS)
HIST-A 0.004 0.000 0.000 0.08 0.35 14.530 0.034 0.001 0.008
HIST-B 0.061 0.000 0.000 0.08 0.35 37.466 0.070 0.014 0.127
A-1 0.012 0.012 1.000 0.90 0.96 5.000 0.500 0.035 0.071
A-2 0.009 0.009 1.000 0.90 0.96 5.000 0.500 0.027 0.054
A-3 0.018 0.018 1.000 0.90 0.96 5.000 0.500 0.053 0.109
B 0.003 0.003 1.000 0.90 0.96 5.000 0.500 0.001 0.018
B-1 0.000 0.000 1.000 0.90 0.96 5.000 0.500 0.001 0.001
C 0.001 0.001 1.000 0.90 0.96 5.000 0.500 0.003 0.006
D 0.002 0.002 1.000 0.90 0.96 5.000 0.500 0.006 0.012
E 0.003 0.003 1.000 0.90 0.96 5.000 0.500 0.009 0.018
F 0.009 0.000 0.000 0.08 0.35 10.210 0.025 0.002 0.020
G 0.007 0.000 0.000 0.08 0.35 9.328 0.028 0.002 0.015
H 0.001 0.001 1.000 0.90 0.96 5.000 0.500 0.003 0.006
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Figure 2. Existing Basins
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Figure 3. Proposed Basins
2.3.1 Historical Basin A
Historical Basin A (“Hist-A”)is comprised of a small area on the northern end of the lot as shown in Fig-
ure 2.
2.3.2 Historical Basin B
Historical Basin B (“Hist-B”) comprises most of the lot area extending from the southern boundary of
Historical Basin A to the southern property boundary as shown in Figure 2.
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2.3.3 Basin A
Basin A is comprised of three impervious roof basins: Basins A-1, A-2 and A-3. Basin A-1 drains to the
east and is captured by a gutter and downspout and transferred to pervious pavers in Basin G near the north
west corner of the structure. Basin A-2 drains to a gutter and downspout system and discharges to the Pavers
in Basin F near the north edge of the sunken walkout. Basin A-3 drains to the west and is captured by a
gutter and downspout, where runoff is transferred to the pervious pavers in Basin F near the entrance.
WQCV and detention requirements are met by the “Pervious Pavers” described in Section 3.1.1, below.
2.3.4 Basin B
Basin B is a small 139 sf basin that consists of a landscape well, window well, and stairway that provides
access to the lower level of the house. Runoff not infiltrated in the planting area will be routed to a deck
drain where it can infiltrate into a gravel bed.
2.3.5 Basin B-1
Basin B-1 is a small 9.2 sf concrete basin that consists of a window well. Basin B-1 runoff is routed to a
deck drain where it can infiltrate in a gravel bed below the concrete.
2.3.6 Basin C
Basin C is a small 68.65 concrete basin that consists of a stairwell for the master bedroom and bathroom.
Basin C runoff is routed to a deck drain where it can infiltrate in a gravel bed below the concrete.
2.3.7 Basin D
Basin D is a 94 sf basin that consists of a landscape well with a planted area. The 94 sf planted area is
allowed to infiltrate into the soil via drainage grate and gravel bed.
2.3.8 Basin E
Basin E is an impervious roof basin that is captured by an gutter and downspout and transferred to pervious
pavers in Basin F. Basin E WQCV and detention requirements are met by the “Pervious Pavers” described
in Section 3.1.1, below.
2.3.9 Basin F
Basin F is a pervious basin composed entirely of pervious pavers. Basin F WQCV and detention require-
ments are met by the “Pervious Pavers” described in Section 3.1.1, below.
2.3.10 Basin G
Basin G is a pervious basin composed entirely of pervious pavers. Basin G WQCV and detention require-
ments are met by the “Pervious Pavers” described in Section 3.1.1, below.
2.3.11 Basin H
Basin H is composed of a concrete patio, which will route runoff to the permeable pavers. Basin H WQCV
and detention requirements are met by the “Pervious Pavers” described in Section 3.1.1, below.
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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.
Due to the nature of the site, overland conveyance is limited.
3. Avoid unnecessary impervious areas.
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, including a sand filter, 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.
The site did not allow for a treatment train approach.
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 safely in mind. BMPs adja-
cent to vehicular traffic are protected by a curb. The stormwater BMPs have been designed with
public safely in mind.
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3.1 General
Low impact design has been utilized where possible to provide WQCV and detention.
Basin Routing is described in Table 2, below.
Table 2. Basin Routing
Sub-Basin ID Path 1 Path 2 Path 3 Final Basin ID WQ BMP ID
A-1 Gutter 1 DS 1 Inlet 1 G Pervious Paver
A-2 Gutter 2a DS 2 Inlet 2 F Pervious Paver
A-3 Gutter 3 DS 3 Inlet 3 F Pervious Paver
B Drainage Grate B Infiltration
C Drainage Grate C Infiltration
D Drainage Grate D Infiltration
E Gutter 2b DS 2 Inlet 2 F Pervious Paver
F Pervious F Pervious Paver
G Pervious G Pervious Paver
H Sheet Flow F F Pervious Paver
3.1.1 Pervious Paver
The Pervious Pavers provide WQCV and detention for the Basins A-1, A-2, A-3, H, and E. Both Basin F
and G shall be composed entirely Pervious Pavers. Runoff from Basins A-2, A-3, and E is directed to the
Pervious Pavers in Basin F via internal drain systems. Likewise, runoff from A-1 is transferred to the Per-
vious Pavers in Basin G via internal drain systems. Basin H drains directly to the pervious paver surface
via sheet flow. Details for the Pervious Pavers can be found on Plan Sheet C.3 (Appendix C, C.3).
Detention Calculation
Pervious Pavers provide water quality treatment and detain flows from Basins A-1, A-2, A-3, E, F, H, and
G. In order to calculated water quality and detention requirements, WCE calculated the total area, imper-
vious area, and time of concentration of the basins. Overall, the basins area tributary to and including the
pervious paver basins (A-1, A-2, A-3, E, F, H, and G) equals 0.058 acres, while the impervious area
equals 0.041 ac.
Based on an overall imperviousness of 70.69 percent, the WQCV in watershed inches is 0.145 in (see Ap-
pendix D). In terms of volume, the WQCV over the tributary area of 0.058 acres is 30.5 cf (0.058 ac X
43560 sf/ac X 0.145 in X 1 ft /12 in). During a 100-year storm, the total 1-hr rainfall depth is 1.23
inches. Therefore, the volume of the 100-yr event is 260 cf (1.23 in X 1ft/12in X 0.058 ac X 1ac/43560ft
= 258.96).
The Pervious Pavers detain water in the lower two layers of soil. These layers are composed of AASHTO
No. 57 and No. 2 stone, respectively. The dimensions listed in the Plan Sheet C.3 (Appendix C, C.3) pro-
vide 927.3 cf of No. 57 and No. 2 soil. With a void ratio of e = 0.30, the Pervious Paver system provides a
storage capacity of 278.2 cf (927.3 cf X 0.3). Therefore, the Pervious Paver system meets WQCV and 100
year detention requirements. Additional storage volume calculations can be found in Appendix E, Deten-
tion.
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3.1.2 Gravel Drains
Basin B Gravel Drain
The total area of Basin B is 139 sf of which up to 139 sf will be impervious. Therefore, a total detention
volume of 14.2 cf is required (1.23 in X 1ft/12in X 139sf). The total WQCV is 3 cf (0.255 in X 1ft/12in
X 139sf). The gravel has a void ratio of 30%. To provide adequate storage, a minimum of 47.3 cf of
gravel is required. The gravel will be placed in a 7 in lift over an 88 sf area yielding 51 cf of gravel.
Basin B-1 Gravel Drain
The total area of Basin B is 9.2 sf of which up to 9.2 sf will be impervious. Therefore, a total detention
volume of 0.94 cf is required (1.23 in X 1ft/12in X 9.2sf). The total WQCV is 0.20 cf (0.255 in X
1ft/12in X 9.2sf). The gravel has a void ratio of 30%. To provide adequate storage, a minimum of 3.1 cf
of gravel is required. The gravel will be placed in a 5 in lift over a 9 sf area yielding 3.75 cf of gravel.
Basin C Gravel Drain
The total area of Basin B is 68.65 sf of which up to 68.65 sf will be impervious. Therefore, a total deten-
tion volume of 7.04 cf is required (1.23 in X 1ft/12in X 68.65 sf). The total WQCV is 1.46 cf (0.255 in X
1ft/12in X 68.65 sf). The gravel has a void ratio of 30%. To provide adequate storage, a minimum of
23.5 cf of gravel is required. The gravel will be placed in a 6 in lift over a 50 sf area yielding 25 cf of
gravel.
Basin D Gravel Drain
The total area of Basin D is 94 sf of which up to 94 sf will be considered impervious. Therefore, a total
detention volume of 9.6 cf is required (1.23 in X 1ft/12in X 94sf). The total WQCV is 2 cf (0.255 in X
1ft/12in X 94sf). The gravel has a void ratio of 30%. To provide adequate storage, a minimum of 32 cf
of gravel is required. The gravel will be placed in a 11 in lift over a 35 sf area yielding 32 cf of gravel.
Table 3. Basin Parameters
BASI NO. TOTAL BASIN
AREA (ACRES)
IMPERVIOUS
AREA (ACRES)
% IMPERV-
IOUS
tc (min)
A-1 0.012 0.012 100 5
A-2 0.009 0.009 100 5
A-3 0.018 0.018 100 5
B 0.003 0.003 100 5
B-1 0.000 0.000 100 5
C 0.001 0.001 100 5
D 0.002 0.002 100 5
E 0.003 0.003 100 5
F 0.009 0.000 0.000 5
G 0.007 0.000 0.000 5
H 0.001 0.001 100 5
TOTAL 0.065 0.049 0.818 5
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3.1.3 24-hr Drain Time Calculation
Calculations were also performed to ensure that pervious areas can drain routed runoff within 24 hours.
These calculations can be found in Table 4, below.
Table 4. Percolation rates for pervious areas.
As shown, each area requires a lower percolation rate than 0.025-0.050 in/min as specified by the Ge-
otechnical Engineer. Therefore, the paver and gravel beds will drain within 24-hrs.
Basin Tributary Area (sf) Vol (cf) v/t (cf/min) Pervious Area (sf) Percolation Rate (in/min)
Pavers 2489.95 255.22 0.177 769.0 0.00277
Basin B 138.9 14.20 0.010 88.0 0.00134
Basin B1 9.2 0.94 0.001 9.0 0.00087
Basin C 68.65 4.30 0.003 33.6 0.00107
Basin D 94 9.60 0.007 35.0 0.00229
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3.1.4 Operation and maintenance
Operation and maintenance recommendations for the permeable pavers can be found in Table 4. These
standards were acquired from Table 8.8 in the URMP.
Table 4. URMP Maintenance Recommendations for Modular Block Pervious Pavement
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Appendix A--NRCS Soils Report
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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
January 16, 2017
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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
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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.
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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
108—Uracca, moist-Mergel complex, 6 to 12 percent slopes, extremely...14
References............................................................................................................16
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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
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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 9/1/17
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 9/1/17
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 9/1/17
9
Custom Soil Resource Report
Soil Map
433960443396114339618433962543396324339639433964643396534339660433960443396114339618433962543396324339639433964643396534339660343438 343445 343452 343459 343466 343473 343480
343438 343445 343452 343459 343466 343473 343480
39° 11' 31'' N 106° 48' 46'' W39° 11' 31'' N106° 48' 44'' W39° 11' 29'' N
106° 48' 46'' W39° 11' 29'' N
106° 48' 44'' WN
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84
0 10 20 40 60
Feet
0 4 8 16 24
Meters
Map Scale: 1:292 if printed on A portrait (8.5" x 11") sheet.
Soil Map may not be valid at this scale.
9/1/17
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 9/1/17
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 9/1/17
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
108 Uracca, moist-Mergel complex,
6 to 12 percent slopes,
extremely
0.4 100.0%
Totals for Area of Interest 0.4 100.0%
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
development of resource plans. If intensive use of small areas is planned, however,
Custom Soil Resource Report
12 9/1/17
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 9/1/17
Aspen-Gypsum Area, Colorado, Parts of Eagle, Garfield, and Pitkin
Counties
108—Uracca, moist-Mergel complex, 6 to 12 percent slopes, extremely
Map Unit Setting
National map unit symbol: jq4h
Elevation: 6,800 to 8,400 feet
Mean annual precipitation: 16 to 19 inches
Mean annual air temperature: 40 to 43 degrees F
Frost-free period: 75 to 95 days
Farmland classification: Not prime farmland
Map Unit Composition
Uracca, moist, and similar soils: 50 percent
Mergel and similar soils: 40 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Uracca, Moist
Setting
Landform: Structural benches, valley sides, alluvial fans
Down-slope shape: Linear
Across-slope shape: Linear
Parent material: Mixed alluvium derived from igneous and metamorphic rock
Typical profile
H1 - 0 to 8 inches: cobbly sandy loam
H2 - 8 to 15 inches: very cobbly sandy clay loam
H3 - 15 to 60 inches: extremely cobbly loamy sand
Properties and qualities
Slope: 6 to 12 percent
Depth to restrictive feature: More than 80 inches
Natural drainage class: Well drained
Runoff class: Medium
Capacity of the most limiting layer to transmit water (Ksat): Moderately high to
high (0.20 to 2.00 in/hr)
Depth to water table: More than 80 inches
Frequency of flooding: None
Frequency of ponding: None
Calcium carbonate, maximum in profile: 10 percent
Available water storage in profile: Very low (about 2.6 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 6e
Hydrologic Soil Group: B
Ecological site: Stony Loam (R048AY237CO)
Other vegetative classification: Stony Loam (null_82)
Hydric soil rating: No
Custom Soil Resource Report
14 9/1/17
Description of Mergel
Setting
Landform: Valley sides, alluvial fans, structural benches
Down-slope shape: Linear
Across-slope shape: Linear
Parent material: Glacial outwash
Typical profile
H1 - 0 to 8 inches: cobbly loam
H2 - 8 to 20 inches: very cobbly sandy loam
H3 - 20 to 60 inches: extremely stony sandy loam
Properties and qualities
Slope: 6 to 12 percent
Depth to restrictive feature: More than 80 inches
Natural drainage class: Well drained
Runoff class: Low
Capacity of the most limiting layer to transmit water (Ksat): Moderately high to
high (0.60 to 6.00 in/hr)
Depth to water table: More than 80 inches
Frequency of flooding: None
Frequency of ponding: None
Calcium carbonate, maximum in profile: 10 percent
Available water storage in profile: Low (about 3.3 inches)
Interpretive groups
Land capability classification (irrigated): 4s
Land capability classification (nonirrigated): 4s
Hydrologic Soil Group: A
Ecological site: Stony Loam (R048AY237CO)
Other vegetative classification: Stony Loam (null_82)
Hydric soil rating: No
Custom Soil Resource Report
15 9/1/17
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
16 9/1/17
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
17 9/1/17
2
Appendix B--FEMA FIRM Map
9/1/17
9/1/17
3
Appendix C--Plan Set
9/1/17
N
08/30/17 DATE OF PUBLICATION
200'400'800'100'
1" = 200'C-0.0
COVER SHEETCURLEY RESIDENCE108 MAPLE AVE., ASPEN, CO01/26/17 PERMIT
CURLEY RESIDENCE
108 MAPLE AVE,
ASPEN CO
NOTES:
1.ALL MATERIALS, WORKMANSHIP, AND CONSTRUCTION OF PUBLIC
IMPROVEMENTS SHALL MEET OR EXCEED THE STANDARDS AND
SPECIFICATIONS SET FORTH IN THE CITY OF ASPEN ("COA") MUNICIPAL
CODE, COA TECHNICAL MANUALS, AND APPLICABLE
STATE AND FEDERAL REGULATIONS. WHERE THERE IS CONFLICT BETWEEN
THESE PLANS AND THE TECHNICAL MANUAL OR ANY APPLICABLE
STANDARDS, THE HIGHER QUALITY STANDARD SHALL APPLY. ALL UTILITY
WORK SHALL BE INSPECTED AND APPROVED BY THE UTILITY.
2.THE CONTRACTOR IS SPECIFICALLY CAUTIONED THAT THE LOCATION
AND/OR ELEVATION OF EXISTING UTILITIES AS SHOWN ON THESE PLANS IS
BASED ON RECORDS OF THE VARIOUS UTILITY COMPANIES AND, WHERE
POSSIBLE, MEASUREMENTS TAKEN IN THE FIELD. THE INFORMATION IS NOT
TO BE RELIED UPON AS BEING EXACT OR COMPLETE.
3.THE CONTRACTOR SHALL HAVE ONE (1) SIGNED COPY OF THE
APPROVED PLANS, ONE (1) COPY OF THE APPROPRIATE CRITERIA AND
SPECIFICATIONS, AND A COPY OF ANY PERMITS AND EXTENSION
AGREEMENTS NEEDED FOR THE JOB ONSITE AT ALL TIMES.
4.THE CONTRACTOR SHALL BE RESPONSIBLE FOR ALL ASPECTS OF
SAFETY INCLUDING, BUT NOT LIMITED TO, EXCAVATION, TRENCHING,
SHORING,TRAFFIC CONTROL, AND SECURITY.
5.IF DURING THE CONSTRUCTION PROCESS CONDITIONS ARE
ENCOUNTERED WHICH COULD INDICATE A SITUATION THAT IS NOT
IDENTIFIED IN THE PLANS OR SPECIFICATIONS, THE CONTRACTOR SHALL
CONTACT THE WOODY CREEK ENGINEERING, LLC IMMEDIATELY.
6.ALL REFERENCES TO ANY PUBLISHED STANDARDS SHALL REFER TO
THE LATEST REVISION OF SAID STANDARD UNLESS SPECIFICALLY STATED
OTHERWISE.
7.THE CONTRACTOR SHALL SUBMIT A TRAFFIC CONTROL PLAN IN
ACCORDANCE WITH MUTCD TO THE APPROPRIATE RIGHT-OF-WAY
AUTHORITY (TOWN, COUNTY OR STATE) FOR APPROVAL PRIOR TO ANY
CONSTRUCTION ACTIVITIES WITHIN OR AFFECTING THE RIGHT-OF-WAY.
THE CONTRACTOR SHALL BE RESPONSIBLE FOR PROVIDING ANY AND ALL
TRAFFIC CONTROL DEVICES AS MAY BE REQUIRED BY THE
CONSTRUCTION ACTIVITIES.
8.THE CONTRACTOR IS RESPONSIBLE FOR PROVIDING ALL LABOR AND
MATERIALS NECESSARY FOR THE COMPLETION OF THE INTENDED
IMPROVEMENTS SHOWN ON THESE DRAWINGS OR AS DESIGNATED TO BE
PROVIDED, INSTALLED, OR CONSTRUCTED UNLESS SPECIFICALLY
NOTED OTHERWISE.
9.THE CONTRACTOR SHALL BE RESPONSIBLE FOR KEEPING ROADWAYS
FREE AND CLEAR OF ALL CONSTRUCTION DEBRIS AND DIRT TRACKED FROM
THE SITE.
10.THE CONTRACTOR SHALL BE RESPONSIBLE FOR RECORDING AS-BUILT
INFORMATION ON A SET OF RECORD DRAWINGS KEPT ON THE
CONSTRUCTION SITE AND AVAILABLE AT ALL TIMES.
11.DIMENSIONS FOR LAYOUT AND CONSTRUCTION ARE NOT TO BE
SCALED FROM ANY DRAWING. IF PERTINENT DIMENSIONS ARE NOT SHOWN,
CONTACT WOODY CREEK ENGINEERING, LLC FOR CLARIFICATION AND
ANNOTATE THE DIMENSION ON THE AS-BUILT RECORD DRAWINGS.
15. THE CONTRACTOR SHALL COMPLY WITH ALL TERMS AND CONDITIONS OF
THE COLORADO PERMIT FOR STORM WATER DISCHARGE, THE STORM
WATER MANAGEMENT PLAN, AND THE EROSION CONTROL PLAN.
16.ALL STRUCTURAL EROSION CONTROL MEASURES SHALL BE
INSTALLED AT THE LIMITS OF CONSTRUCTION PRIOR TO ANY OTHER
EARTH-DISTURBING ACTIVITY. ALL EROSION CONTROL MEASURES SHALL BE
MAINTAINED IN GOOD REPAIR BY THE CONTRACTOR UNTIL SUCH TIME AS
THE ENTIRE DISTURBED AREA IS STABILIZED WITH HARD SURFACE OR
LANDSCAPING.
17.THE CONTRACTOR SHALL SEQUENCE INSTALLATION OF UTILITIES IN
SUCH A MANNER AS TO MINIMIZE POTENTIAL UTILITY CONFLICTS. IN
GENERAL, STORM SEWER AND SANITARY SEWER SHOULD BE
CONSTRUCTED PRIOR TO INSTALLATION OF THE WATER LINES AND DRY
UTILITIES.
18.HEAT TAPE ALL PIPES.
19.100'-0" = 7932.36'
VICINITY MAP
06/16/17 RESUBMITTAL
08/30/17 RESUBMITTAL
8/30/2017
9/1/17
LOT 108
2,451 SQ.
FT. +/-
CITY OF ASPEN
GPS #5
1767.
0
7'S64°4
8'
1
7
"
W
CITY OF ASPEN
GPS #41178.78'S13°15'49"WCOMMON
O
P
EN
S
P
A
CE MA
P
L
E
L
A
N
E
3
7
.
0
0
'
S
4
4
°
2
9
'
2
2
"
E
71.01'S32°43'27"W3
3
.
7
9
'
N
4
4
°
2
9
'
2
2
"W71.79'N30°13'30"E5'
S
E
T
B
A
C
K
BASIN
A-1
AREA=512
SF
BASIN
A-2
AREA=375
SF
BASIN
A-3
AREA=783
SF
BASIN
E
AREA=118
SF
BASIN
F
AREA=390 SF
BASIN
G
AREA=313
SF
BASIN B
AREA=138.9 SF
BASIN H
AREA=36 SF
BASIN C
AREA=68.65 SF
BASIN D
AREA=94 SF
7931
7932
7932
10' SETBACKBASIN B-1
AREA=9.24 SF
LOT 108
2,451 SQ.
FT. +/-
CITY OF ASPEN
GPS #5
1767.
0
7'S64°4
8'
1
7
"
W
CITY OF ASPEN
GPS #41178.78'S13°15'49"WCOMMON
O
P
EN
S
PAC
E MA
P
L
E
L
A
N
E
3
7
.
0
0
'
S
4
4
°
2
9
'
2
2
"
E
71.01'S32°43'27"W3
3
.
7
9
'N4
4
°
2
9
'
2
2
"W71.79'N30°13'30"E5'
S
E
T
B
A
C
K
BASIN
HIST-B
AREA=2677
SF
BASIN
HIST-A
AREA=165
SF
79327932
793179317932
10' SETBACKN
08/30/17 DATE OF PUBLICATION
10'20'40'5'
1" = 10'
C-1.0
BASINSCURLEY RESIDENCE108 MAPLE AVE., ASPEN, CO01/26/17 PERMIT
NOTES:
1.EXISTING DRAINAGE BASIN CONSISTS OF LOT
AND A PORTION OF THE ROW.
2.PROPOSED DRAINAGE BASINS ARE DETERMINED
BY TOPOGRAPHY AND STRUCTURE.
HISTORICAL DRAINAGE BASINS PROPOSED DRAINAGE BASINS
HISTORICAL DRAINAGE BASINS
PROPOSED DRAINAGE BASINS
NOTES:
1.DOWNSPOUT 1 DISCHARGES TO INLET 1. INLET 1
DISCHARGES TO BASIN G THROUGH PERFORATED
PIPE. SEE C-2.0.
2.DOWNSPOUT 2 DISCHARGES TO INLET 2. INLET 2
DISCHARGES TO BASIN F THROUGH PERFORATED
PIPE. SEE C-2.0.
3.DOWNSPOUT 3 DISCHARGES TO INLET 3. INLET 3
DISCHARGES TO BASIN F THROUGH PERFORATED
PIPE. SEE C-2.0.
PROPOSED CONTOUR
EXISTING CONTOUR
BASIN BOUNDARY
PROPERTY LINE
06/16/17 RESUBMITTAL
08/30/17 RESUBMITTAL
8/30/2017
9/1/17
LOT 108
2,451 SQ.
FT. +/-
14"/8'
1767.
0
7'S64°4
8'
1
7
"
WCOMMON O
P
EN
S
P
ACE MA
P
L
E
L
AN
E
3
7
.
0
0
'
S
4
4
°
2
9
'
2
2
"
E
71.01'S32°43'27"W3
3
.
7
9
'
N
4
4
°
2
9
'
2
2
"W71.79'N30°13'30"E5'
S
E
T
B
A
C
K
FOUNDATION
DRY WELL
SEE DETAIL C6.0-3
FOUNDATION DRAIN
SEE DETAIL C6.0-2
CONNECT
DOWNSPOUT 1 TO
PERFORATED PIPE 1
DOWNSPOUT 1
GUTTER 1
GUTTER 2B
GUTTER 2A
CONNECT
DOWNSPOUT 2 TO
PERFORATED
PIPE 2
DOWNSPOUT 2
GUTTER 3
CONNECT
DOWNSPOUT 3 TO
PERFORATED PIPE 3
DOWNSPOUT 3
PERFORATED PIPE 1
3" PVC
CAP END
PERFORATED PIPE 2
3" PVC
CAP END
PERFORATED PIPE
2 -- 3" PVC
CAP END
GAS METER
PERVIOUS PAVERS
SEE C-3.0 & C-4.0
B-B
A-A
D-D
C-C
ELECTRIC METER
PROVIDE MIN 30-IN
SEPARATION FROM
GAS TO ELECTRIC
SERVICES
PLANTER DRAINAGE GRATE
ZURN TRAP DRAIN
Z-742
(SEE C-4.0)
4" PVC PIPE
7931
7932
FOUNDATION
DRAIN
SEE DETAIL C6.0-2
FOUNDATION DRAIN
SEE DETAIL C6.0-1
STAIRWELL DRAINAGE GRATE
ZURN TRAP DRAIN
Z-742
(SEE C-4.0)
4" PVC PIPE
7932
79327932
793179317932
WINDOW WELL DRAINAGE GRATE
ZURN TRAP DRAIN
Z-742
(SEE C-4.0)LANDINGSTEPSDOWNCONCRETE WINDOW WELL DRAINAGE GRATE
ZURN TRAP DRAIN
Z-742
(SEE C-4.0)
4" PVC PIPE -4.2%-3.5%-2.8%-5.
7
%-1.3%-2.
5
%
-3.
3
%-1.0%-2.
5
%
-2.
5
%
-2.
5
%
-7.
1
%
-4.
4
%
-4.
4
%
GR:7931.81
GR:7931.86
INSTALL 30 MIL
IMPERMEABLE LINER
WHERE PAVERS RUN
ALONG THE PROP. LINE
GRAVEL BED
88.0 SF BY 7" DEEP
TOP OF GRAVEL EL. =
BOTTOM OF SLAB
YIELDS 51CF GRAVEL
10' SETBACKGRAVEL BED
50 SF BY 6" DEEP
YIELDS 25 CF.
TOP OF GRAVEL EL. =
BOTTOM OF SLAB
GRAVEL BED
9 SF BY 5" DEEP
YIELDS 3.75 CF.
TOP OF GRAVEL EL. =
BOTTOM OF SLAB
RELOCATE WATER SHUT OFF TO NEW CONNECTION
GRAVEL BED
35 SF BY 11" DEEP
YIELDS 14.6 CF.
TOP OF GRAVEL EL. =
BOTTOM OF SLAB
FFE = 7932.36'
GR:7928.06
GR:7928.10
GR:7928.10
GR:7928.06
GR:7928.00
GR:7931.24
GR:7931.28
GR:7931.34
GR:7931.42
GR:7931.55
GR:7931.57
GR:7931.47
GR:7931.43
GR:7931.40
GR:7930.37
GR:7930.61
GR:7930.44
GR:7932.12
GR:7932.36
GR:7932.10
GR:7931.80
GR:7932.36
GR:7931.31
GR:7931.39
GR:7931.98
GR:7931.72
GR:7931.77
GR:7931.68
GR:7931.63
GR:7930.99
GR:7931.42
GR:7931.47
GR:7931.52
GR:7931.70
GR:7931.70
GR:7931.79
GR:7932.01
GR:7932.06
GR:7931.87
GR:7931.74
RELOCATE WATER SHUT OFF TO NEW CONNECTION
ON ADJACENT PROPERTY
N
5'10'20'2.5'
1" = 5'
C-2.0
GRADING &
DRAINAGECURLEY RESIDENCE108 MAPLE AVE., ASPEN, COEXISTING TREE REMOVED
EXISTING TREE KEPT
EXISTING CONTOUR
PROPOSED CONTOUR
NOTES:
1.ROOF AREA = 1788 SF, ENTRANCE CONCRETE AREAS= 327 SF
2.TOTAL IMPERVIOUS AREA=2115 SF.
3.PERVIOUS PAVER AREA = 722 SF
4.ROOF/PAVER RATIO=2.93 SUBMIT A VARIANCE
5.REPLACE CURB AND GUTTER IF DAMANGED DURING
CONSTRUCTION. REPLACE IN-KIND TYPE, FLOWLINE, TOP BACK OF
CURB AND LOCATION.
6.100'-0"=7932.36'
7.DOWNSPOUT 1 DISCHARGES TO INLET 1. INLET 1 DISCHARGES TO
BASIN G THROUGH PERFORATED PIPE.
8.DOWNSPOUT 2 DISCHARGES TO INLET 2. INLET 2 DISCHARGES TO
BASIN F THROUGH PERFORATED PIPE.
9.DOWNSPOUT 3 DISCHARGES TO INLET 3. INLET 3 DISCHARGES TO
BASIN F THROUGH PERFORATED PIPE.
10.EXISTING DRAINAGE BASIN CONSISTS OF LOT AND A PORTION OF
THE ROW.
11.PROPOSED DRAINAGE BASINS ARE DETERMINED BY TOPOGRAPHY
AND STRUCTURE.
7910
SPOT ELEVATION XXXX.XX
CONC. = CONCRETE
HP = HIGH POINT
TD = TRENCH DRAIN
08/30/17 DATE OF PUBLICATION
01/26/17 PERMIT
PROPERTY LINE
VEGETATED AREA
PERVIOUS PAVERS
INLET
UTILITIES
CONCRETE
06/16/17 RESUBMITTAL
08/30/17 RESUBMITTAL
8/30/2017
9/1/17
N
10'20'40'5'
1" = 10'C-3.0
PROFILES &
CROSS-SECTIONSCURLEY RESIDENCE108 MAPLE AVE., ASPEN, COVERTICAL SCALE
EXAGGERATED BY 10
SECTION D-D
SOUTH TO NORTH PROPERTY
LINES
SECTION A-A
FRONT DOOR PAVER SECTION
SECTION B-B
CURB TO ENTRANCESECTION C-C
FACE OF STRUCTURE PARALLEL
TO ROAD
NOTES:
1.INLETS AND INLET GRATES ARE NDS 9" CATCH
BASIN SERIES AND NDS 980-9" SQ. GRATES. SEE
DETAILS C-4.0.
08/30/17 DATE OF PUBLICATION
1/26/17 PERMIT
06/16/17 RESUBMITTAL
08/30/17 RESUBMITTAL
8/30/2017
9/1/17
C-4.0
DETAILSCURLEY RESIDENCE108 MAPLE AVE., ASPEN, COCATCH BASIN AND GRATE DETAIL
08/30/17 DATE OF PUBLICATION
01/26/17 PERMIT
DEPTH (SEE C.3)
DEPTH (SEE C.3)
PERVIOUS PAVER (TYP)
SEE 3.0 FOR SITE
SPECIFIC
CROSS-SECTION
ZURN Z742
DETAIL 1
TYPICAL EGRESS STAIR
AND WINDOW DRAIN
DETAIL 06/16/17 RESUBMITTAL
08/30/17 RESUBMITTAL
8/30/2017
9/1/17
S64°4
8'
1
7
"
WCOMMON O
P
EN
S
P
ACE MA
P
L
E
L
AN
E
3
7
.
0
0
'
S
4
4
°
2
9
'
2
2
"
E
71.01'S32°43'27"W3
3
.
7
9
'
N
4
4
°
2
9
'
2
2
"W71.79'N30°13'30"E5'
S
E
T
B
AC
K
GAS METER
ELECTRIC METER
PROVIDE MIN 30-IN
SEPARATION FROM
GAS TO ELECTRIC
SERVICES
10' SETBACKRELOCATE WATER SHUT OFF TO NEW CONNECTION
RELOCATE WATER SHUT OFF TO NEW CONNECTION
ON ADJACENT PROPERTY
N
5'10'20'2.5'
1" = 5'
C-5.0
UTILITIESCURLEY RESIDENCE108 MAPLE AVE., ASPEN, COEXISTING TREE REMOVED
EXISTING TREE KEPT
EXISTING CONTOUR
PROPOSED CONTOUR
NOTES:
1.CONNECT SANITARY TO EXISTING SERVICE.
2.CONNECT WATER TO EXISTING SERVICE.
3.REROUTE GAS TO NEW METER. USE EXISTING
SERVICE TO NEW METER LOCATION.
4.REROUTE ELECTRIC. USE EXISTING SERVICE.
5.CONNECT TO EXISTING CABLE & PHONE
SERVICES.
7910
SPOT ELEVATION XXXX.XX
CONC. = CONCRETE
HP = HIGH POINT
TD = TRENCH DRAIN
08/30/17 DATE OF PUBLICATION
01/26/17 PERMIT
UTILITIES
06/16/17 RESUBMITTAL
08/30/17 RESUBMITTAL
8/30/2017
9/1/17
FOUNDATION
DRY WELL
SEE DETAIL C6.0-3
FOUNDATION DRAIN
SEE DETAIL C6.0-2
FOUNDATION
DRAIN
SEE DETAIL C6.0-2
FOUNDATION DRAIN
SEE DETAIL C6.0-1
N
5'10'20'2.5'
1" = 5'
C-6.0
FOUNDATION
PLAN & DETAILSCURLEY RESIDENCE108 MAPLE AVE., ASPEN, CO06/16/17 DATE OF PUBLICATION
01/26/17 PERMITFOUNDATION PLAN
DETAIL 3
DRY WELL
DETAIL 1
CIRCULAR FOUNDATION DRAIN
DETAIL 2
HYDRODUCT COIL 600
06/16/17 RESUBMITTAL
8/30/2017
9/1/17
S64°4
8'
1
7
"
W
COMMON
O
PEN
S
P
A
CE MA
P
L
E
L
AN
E
3
7
.
0
0
'
S
4
4
°
2
9
'
2
2
"
E
71.01'S32°43'27"W3
3
.
7
9
'
N
4
4
°
2
9
'
2
2
"W71.79'N30°13'30"E5'
S
E
T
B
A
C
K
EN
TR
ANC
E
10' SETBACKN
5'10'20'2.5'
1" = 5'
C-7.0
SEDIMENT AND
EROSION
CONTROLCURLEY RESIDENCE108 MAPLE AVE., ASPEN, COSEDIMENT FENCE
06/16/17 DATE OF PUBLICATION
01/26/17 PERMIT
ROCK SOCK DETAIL
SEDIMENT FENCE DETAIL
06/16/17 RESUBMITTAL
8/30/2017
9/1/17
4
Appendix D--Hydrologic Calculations
9/1/17
36543149.xls Page 1
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:108 Maple
Catchment ID:A-1
I.Catchment Hydrologic Data
Catchment ID =A-1
Area =0.012 Acres
Percent Imperviousness =100.00 %
NRCS Soil Type =B 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 =0.106 cfs
Rainfall Intensity at Regional Tc, I =4.67 inch/hr Peak Flowrate, Qp =0.052 cfs
Rainfall Intensity at User-Defined Tc, I =6.33 inch/hr Peak Flowrate, Qp =0.071 cfs
9/1/17
36563149.xls Page 1
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:108 Maple
Catchment ID:A-2
I.Catchment Hydrologic Data
Catchment ID =A-2
Area =0.009 Acres
Percent Imperviousness =100.00 %
NRCS Soil Type =B 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 =0.081 cfs
Rainfall Intensity at Regional Tc, I =4.67 inch/hr Peak Flowrate, Qp =0.040 cfs
Rainfall Intensity at User-Defined Tc, I =6.33 inch/hr Peak Flowrate, Qp =0.054 cfs
9/1/17
36583149.xls Page 1
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:108 Maple
Catchment ID:A-3
I.Catchment Hydrologic Data
Catchment ID =A-3
Area =0.018 Acres
Percent Imperviousness =100.00 %
NRCS Soil Type =B 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 =0.163 cfs
Rainfall Intensity at Regional Tc, I =4.67 inch/hr Peak Flowrate, Qp =0.080 cfs
Rainfall Intensity at User-Defined Tc, I =6.33 inch/hr Peak Flowrate, Qp =0.109 cfs
9/1/17
36603149.xls Page 1
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:108 Maple
Catchment ID:B-1
I.Catchment Hydrologic Data
Catchment ID =B-1
Area =0.000 Acres
Percent Imperviousness =100.00 %
NRCS Soil Type =B 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 =0.002 cfs
Rainfall Intensity at Regional Tc, I =4.67 inch/hr Peak Flowrate, Qp =0.001 cfs
Rainfall Intensity at User-Defined Tc, I =6.33 inch/hr Peak Flowrate, Qp =0.001 cfs
9/1/17
36623149.xls Page 1
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:108 Maple
Catchment ID:B
I.Catchment Hydrologic Data
Catchment ID =B
Area =0.003 Acres
Percent Imperviousness =100.00 %
NRCS Soil Type =B 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 =0.027 cfs
Rainfall Intensity at Regional Tc, I =4.67 inch/hr Peak Flowrate, Qp =0.013 cfs
Rainfall Intensity at User-Defined Tc, I =6.33 inch/hr Peak Flowrate, Qp =0.018 cfs
9/1/17
36643149.xls Page 1
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:108 Maple
Catchment ID:C
I.Catchment Hydrologic Data
Catchment ID =C
Area =0.001 Acres
Percent Imperviousness =100.00 %
NRCS Soil Type =B 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 =0.009 cfs
Rainfall Intensity at Regional Tc, I =4.67 inch/hr Peak Flowrate, Qp =0.004 cfs
Rainfall Intensity at User-Defined Tc, I =6.33 inch/hr Peak Flowrate, Qp =0.006 cfs
9/1/17
36663149.xls Page 1
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:108 Maple
Catchment ID:D
I.Catchment Hydrologic Data
Catchment ID =D
Area =0.002 Acres
Percent Imperviousness =100.00 %
NRCS Soil Type =B 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
9/1/17
36683149.xls Page 1
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:108 Maple
Catchment ID:E
I.Catchment Hydrologic Data
Catchment ID =E
Area =0.003 Acres
Percent Imperviousness =100.00 %
NRCS Soil Type =B 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 =0.027 cfs
Rainfall Intensity at Regional Tc, I =4.67 inch/hr Peak Flowrate, Qp =0.013 cfs
Rainfall Intensity at User-Defined Tc, I =6.33 inch/hr Peak Flowrate, Qp =0.018 cfs
9/1/17
36703149.xls Page 1
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:108 Maple
Catchment ID:F
I.Catchment Hydrologic Data
Catchment ID =F
Area =0.009 Acres
Percent Imperviousness =0.00 %
NRCS Soil Type =B 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 =0.35
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.08
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 0.0250 10 0.08 N/A 0.04 4.37
1
2
3
4
5
Sum 10 Computed Tc =4.37
Regional Tc =10.06
User-Entered Tc =5.00
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =6.62 inch/hr Peak Flowrate, Qp =0.021 cfs
Rainfall Intensity at Regional Tc, I =4.66 inch/hr Peak Flowrate, Qp =0.015 cfs
Rainfall Intensity at User-Defined Tc, I =6.33 inch/hr Peak Flowrate, Qp =0.020 cfs
9/1/17
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CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:108 Maple
Catchment ID:G
I.Catchment Hydrologic Data
Catchment ID =G
Area =0.007 Acres
Percent Imperviousness =0.00 %
NRCS Soil Type =B 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 =0.35
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.08
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 0.0280 9 0.08 N/A 0.04 4.02
1
2
3
4
5
Sum 9 Computed Tc =4.02
Regional Tc =10.05
User-Entered Tc =5.00
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =6.79 inch/hr Peak Flowrate, Qp =0.017 cfs
Rainfall Intensity at Regional Tc, I =4.66 inch/hr Peak Flowrate, Qp =0.011 cfs
Rainfall Intensity at User-Defined Tc, I =6.33 inch/hr Peak Flowrate, Qp =0.015 cfs
9/1/17
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CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:108 Maple
Catchment ID:H
I.Catchment Hydrologic Data
Catchment ID =H
Area =0.001 Acres
Percent Imperviousness =100.00 %
NRCS Soil Type =B 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 =0.009 cfs
Rainfall Intensity at Regional Tc, I =4.67 inch/hr Peak Flowrate, Qp =0.004 cfs
Rainfall Intensity at User-Defined Tc, I =6.33 inch/hr Peak Flowrate, Qp =0.006 cfs
9/1/17
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CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:108 Maple
Catchment ID:HIST-A
I.Catchment Hydrologic Data
Catchment ID =HIST-A
Area =0.004 Acres
Percent Imperviousness =0.00 %
NRCS Soil Type =B 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 =0.35
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.08
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 0.0342 15 0.08 N/A 0.05 4.70
1
2
3
4
5
Sum 15 Computed Tc =4.70
Regional Tc =10.08
User-Entered Tc =5.00
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =6.46 inch/hr Peak Flowrate, Qp =0.009 cfs
Rainfall Intensity at Regional Tc, I =4.65 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
9/1/17
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CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:108 Maple
Catchment ID:HIST-B
I.Catchment Hydrologic Data
Catchment ID =HIST-B
Area =0.061 Acres
Percent Imperviousness =0.00 %
NRCS Soil Type =B 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 =0.35
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.08
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 37 0.08 N/A 0.10 5.96
1
2
3
4
5
Sum 37 Computed Tc =5.96
Regional Tc =10.21
User-Entered Tc =5.96
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =5.93 inch/hr Peak Flowrate, Qp =0.127 cfs
Rainfall Intensity at Regional Tc, I =4.62 inch/hr Peak Flowrate, Qp =0.099 cfs
Rainfall Intensity at User-Defined Tc, I =5.93 inch/hr Peak Flowrate, Qp =0.127 cfs
9/1/17
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CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:108 Maple
Catchment ID:A-1
I.Catchment Hydrologic Data
Catchment ID =A-1
Area =0.012 Acres
Percent Imperviousness =100.00 %
NRCS Soil Type =B 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 =0.052 cfs
Rainfall Intensity at Regional Tc, I =2.43 inch/hr Peak Flowrate, Qp =0.026 cfs
Rainfall Intensity at User-Defined Tc, I =3.29 inch/hr Peak Flowrate, Qp =0.035 cfs
9/1/17
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CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:108 Maple
Catchment ID:A-2
I.Catchment Hydrologic Data
Catchment ID =A-2
Area =0.009 Acres
Percent Imperviousness =100.00 %
NRCS Soil Type =B 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 =0.040 cfs
Rainfall Intensity at Regional Tc, I =2.43 inch/hr Peak Flowrate, Qp =0.020 cfs
Rainfall Intensity at User-Defined Tc, I =3.29 inch/hr Peak Flowrate, Qp =0.027 cfs
9/1/17
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CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:108 Maple
Catchment ID:A-3
I.Catchment Hydrologic Data
Catchment ID =A-3
Area =0.018 Acres
Percent Imperviousness =100.00 %
NRCS Soil Type =B 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 =0.079 cfs
Rainfall Intensity at Regional Tc, I =2.43 inch/hr Peak Flowrate, Qp =0.039 cfs
Rainfall Intensity at User-Defined Tc, I =3.29 inch/hr Peak Flowrate, Qp =0.053 cfs
9/1/17
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CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:108 Maple
Catchment ID:B-1
I.Catchment Hydrologic Data
Catchment ID =B-1
Area =0.000 Acres
Percent Imperviousness =100.00 %
NRCS Soil Type =B 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 =0.001 cfs
Rainfall Intensity at Regional Tc, I =2.43 inch/hr Peak Flowrate, Qp =0.000 cfs
Rainfall Intensity at User-Defined Tc, I =3.29 inch/hr Peak Flowrate, Qp =0.001 cfs
9/1/17
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CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:108 Maple
Catchment ID:B
I.Catchment Hydrologic Data
Catchment ID =B
Area =0.003 Acres
Percent Imperviousness =100.00 %
NRCS Soil Type =B 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 =0.013 cfs
Rainfall Intensity at Regional Tc, I =2.43 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
9/1/17
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CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:108 Maple
Catchment ID:C
I.Catchment Hydrologic Data
Catchment ID =C
Area =0.001 Acres
Percent Imperviousness =100.00 %
NRCS Soil Type =B 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
9/1/17
36923149.xls Page 1
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:108 Maple
Catchment ID:D
I.Catchment Hydrologic Data
Catchment ID =D
Area =0.002 Acres
Percent Imperviousness =100.00 %
NRCS Soil Type =B 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
9/1/17
36943149.xls Page 1
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:108 Maple
Catchment ID:E
I.Catchment Hydrologic Data
Catchment ID =E
Area =0.003 Acres
Percent Imperviousness =100.00 %
NRCS Soil Type =B 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 =0.013 cfs
Rainfall Intensity at Regional Tc, I =2.43 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
9/1/17
36963149.xls Page 1
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:108 Maple
Catchment ID:F
I.Catchment Hydrologic Data
Catchment ID =F
Area =0.009 Acres
Percent Imperviousness =0.00 %
NRCS Soil Type =B 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 =0.08
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.08
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 0.0250 10 0.08 N/A 0.04 4.37
1
2
3
4
5
Sum 10 Computed Tc =4.37
Regional Tc =10.06
User-Entered Tc =5.00
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =3.44 inch/hr Peak Flowrate, Qp =0.002 cfs
Rainfall Intensity at Regional Tc, I =2.42 inch/hr Peak Flowrate, Qp =0.002 cfs
Rainfall Intensity at User-Defined Tc, I =3.29 inch/hr Peak Flowrate, Qp =0.002 cfs
9/1/17
36983149.xls Page 1
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:108 Maple
Catchment ID:G
I.Catchment Hydrologic Data
Catchment ID =G
Area =0.007 Acres
Percent Imperviousness =0.00 %
NRCS Soil Type =B 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 =0.08
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.08
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 0.0280 9 0.08 N/A 0.04 4.02
1
2
3
4
5
Sum 9 Computed Tc =4.02
Regional Tc =10.05
User-Entered Tc =5.00
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =3.53 inch/hr Peak Flowrate, Qp =0.002 cfs
Rainfall Intensity at Regional Tc, I =2.43 inch/hr Peak Flowrate, Qp =0.001 cfs
Rainfall Intensity at User-Defined Tc, I =3.29 inch/hr Peak Flowrate, Qp =0.002 cfs
9/1/17
37003149.xls Page 1
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:108 Maple
Catchment ID:H
I.Catchment Hydrologic Data
Catchment ID =H
Area =0.001 Acres
Percent Imperviousness =100.00 %
NRCS Soil Type =B 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
9/1/17
37023149.xls Page 1
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:108 Maple
Catchment ID:HIST-A
I.Catchment Hydrologic Data
Catchment ID =HIST-A
Area =0.004 Acres
Percent Imperviousness =0.00 %
NRCS Soil Type =B 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 =0.08
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.08
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 0.0342 15 0.08 N/A 0.05 4.70
1
2
3
4
5
Sum 15 Computed Tc =4.70
Regional Tc =10.08
User-Entered Tc =5.00
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =3.36 inch/hr Peak Flowrate, Qp =0.001 cfs
Rainfall Intensity at Regional Tc, I =2.42 inch/hr Peak Flowrate, Qp =0.001 cfs
Rainfall Intensity at User-Defined Tc, I =3.29 inch/hr Peak Flowrate, Qp =0.001 cfs
9/1/17
37043149.xls Page 1
CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD
Project Title:108 Maple
Catchment ID:HIST-B
I.Catchment Hydrologic Data
Catchment ID =HIST-B
Area =0.061 Acres
Percent Imperviousness =0.00 %
NRCS Soil Type =B 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 =0.08
Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.)
5-yr. Runoff Coefficient, C-5 =0.08
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 37 0.08 N/A 0.10 5.96
1
2
3
4
5
Sum 37 Computed Tc =5.96
Regional Tc =10.21
User-Entered Tc =5.96
IV.Peak Runoff Prediction
Rainfall Intensity at Computed Tc, I =3.08 inch/hr Peak Flowrate, Qp =0.014 cfs
Rainfall Intensity at Regional Tc, I =2.41 inch/hr Peak Flowrate, Qp =0.011 cfs
Rainfall Intensity at User-Defined Tc, I =3.08 inch/hr Peak Flowrate, Qp =0.014 cfs
9/1/17
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
9/1/17
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
9/1/17
5
Appendix E—Detention
9/1/17
Bottom Slope =0.02ft/ftBottom Slope =0.02ft/ftBottom W =4ftBottom W =4ftDepth =1.33ftDepth =1.33ftHorizontal L =37.24ftHorizontal L =71.78ftArea =5.48ft^2Area =5.48ft^2Volume =204.0752ft^3Volume =393.3544ft^3Bottom Slope =0.05ft/ftBottom Slope =0.05ft/ftBottom W =4.74ftBottom W =6ftDepth =1.33ftDepth =1.33ftHorizontal L =37.24ftHorizontal L =19.02ftArea =5.74251ft^2Area =7.08ft^2Volume =213.8511ft^3Volume =134.6616ft^3Void Ratio ( e ) =0.3Total Volume = 945.9423Storage Volume =283.7827Pervious Paver CalculatorArea Two Area ThreeHorizontal L = Length pavers run across surfaceArea FourHorizontal L = Length pavers run across surfaceArea OneDepthBottom WDepthBottom WArea One (V calculation above)DepthBottom WDepthBottom WArea Three (V calculation above)9/1/17
6
Appendix F—McLaughlin Report
9/1/17
September 15, 2001
Smuggler Park Home Owners Association
Mark Hesselschwerdt, President
310 Oak Lane
Aspen, Colorado 81611
RE: Smuggler Park Drainage Review – A1-008.01
Dear Mark:
This letter is a summary of our review of the existing drainage system within Smuggler
Park.
Smuggler Park is an 85-unit mobile home park inside the City of Aspen. The park was
installed in the 1960’s and sits on a total of 9.77 acres. The park is about 90% developed
with homes, driveways, roads, sidewalks, and other surfaces. In 1983 Centennial
Engineering designed and the Homeowners installed a road and drainage system for the
Park. Concrete roads were installed along with curb and gutter and a series of inlets,
collection piping, manholes, and other drainage facilities to collect and remove storm
water from the site. I have attached a copy of the original road and drainage design
drawings for your reference and information.
The City of Aspen has little or no information on the existing drainage system and
currently is requiring all homes applying for permits to remodel or replace homes to
install separate storm collection and disposal systems. This is the impetus of this report.
If the existing drainage system meets current Interim Design Standards for Storm Water
Collection, then individual homeowners would not be required to install their own
facilities. MWE was asked to verify that the existing collection system does exist and
verify if the capacity of the system meets the current design standards.
The first task performed by MWE was to verify that the existing system did indeed exist
and verify the size of the lines and locations of the inlets. The attached drawing shows the
asbuilt conditions of the system. Only one inlet does not exist and two additional inlets
have been added to collect flows from the area East of Smuggler Park that was added in
the mid 1980. This area included an additional 16 mobile homes to the drainage system
and approximately1.61 acres. This area is not part of the Smuggler Park Home Owners
9/1/17
Association, but was added to the drainage system since the storms flows from the area
drain into the Smuggler Park roads.
The pipe sizes do match the original design drawing of 15” and 18” RCP lines at slopes
of 0.5% to 2.77%. All of the roads include curb and gutter to collect and direct the storm
water to the inlets. The curb, gutter, and inlets meet current City of Aspen Standards
Interim Design Standards. A site inspection of the system during a recent storm event
showed the system working very well to collect, direct, and handle the flows generated
on site. The inlets, manholes, and piping are free of debris and show little accumulation
of silts or sands. The storm flows keeps the inlets boxes clean during each storm event.
The flows generated from the Smuggler Park site exit the Park at Gibson Avenue. In
Gibson Avenue, MWE followed a series inlets and collection boxes consisting of 18”
RCP and larger piping down Gibson Avenue to Neale Avenue and then to No Problem
Bridge Park where it discharged into the detention basin at the Park before the storm
flows entered the Roaring Fork River. Our review and report does not include the Gibson
Avenue drainage system nor the sizing of the detention pond. Since this system was
added to the Smuggler Park system at a later date by the City of Aspen, we assume it has
been designed it to meet the City of Aspen drainage standards.
MWE next verified the flows generated from Smuggler Park and compared the flows to
the existing drainage system’s capacity to handle those flows. The Park was separated
into tributary areas that drained into each inlet and in turn, to a series of collection piping
that connects the inlets. MWE used the City of Aspen’s Interim Design Standards for
calculation of the flows generated. The Rational Method was used for all calculations
based upon the following:
• No drainage swales or streams exist within the site
• All roadways use curb and gutter to collect and direct the flows into inlets
• 90% developed area (ie C value for runoff coefficient = 0.9)
• 5 year frequency storm event
• Wright McLaughlin 1973 Time Intensity Frequency Curves
• Time of Concentration Initial = L/180 + 10 minutes
• Time of Concentration for each additional basin adds Pipe Flow Time
• Using Chezy-Manning Equation to calculate capacity of existing lines based upon
size, material, slope of pipe.
• Basin 9A flows off site
An attached summary of the pipe collection system is attached showing the piping
segment number, size, slope, capacity, the tributary area, time of concentration, intensity,
calculated or generated flows from the site, and status of pipe. The status of the pipe
compares the design capacity to the actual calculated flow. If the capacity is greater than
then actual generated flow, then that pipe segment meets the City of Aspen Storm Drain
Design Requirements.
9/1/17
Conclusion: In all cases the capacity of the existing pipe segement exceeded the actual
flow generated from the site. Thus, the drainage system as installed in 1983 by the Home
Owners meets and exceeds the City of Aspen’s Interim Design Standards for Storm
Runoff Design. Smuggler Park’s curb and gutter system is adequate to collect and direct
the storm flows to associated inlets, where the piping system is adequately sized to
collect and transfer the storm water throughout the Park for discharge into the Gibson
Avenue drainage system. The City of Aspen may wish to review the Gibson Avenue
drainage system for compliance to the Interim Design Standards and to assure Smuggler
Park that their system will not block or impede the flows from the Park.
Based upon this report and study, the Home Owners within Smuggler Park should not be
required to design and install additional drainage collection systems and/or associated
drywells for handling storage of Storm Runoff from their individual sites. The existing
system is capable of handling all flows from a 5 year event. Although we did not
perform calculations for flows above a 5 year event, flows greater than a 5 year event
look as if they will be safely routed along the surface following the streets with in the
Park.
Please review and comment. If you need additional information, please feel free to
contact me at any time.
Very Truly Yours,
G. Dean Derosier, P. E.
Attachments – dwgs/tables
Cc: Nick Adeh – City of Aspen
MWE - Denver
A1-008-01/drainagereport/gdd
9/1/17