HomeMy WebLinkAboutFile Documents.RACE ST.0084.2019 (2).ARBKGrading and Drainage Report
Prepared for
541 Race Project
541 Race Street, Aspen
P.O. Box 575
Woody Creek, Colorado 81656
970-309-7130
Prepared By
Josh Rice, P.E.
Revised February 12, 2019
Revised April 12, 2018
Revised October 4, 2017
March 21, 2017
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I hereby affirm that this report and the accompanying plans for the drainage improvements 541 Race Alley,
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.
1/11/20182/21/2018
4/01/2019
Reviewed by Engineering
05/15/2019 1:28:05 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 EX1 ...................................................................................................................................... 3
2.3.2 Historical Basin EX2 ...................................................................................................................................... 3
2.3.3 Basin A .......................................................................................................................................................... 3
2.3.4 Basin B .......................................................................................................................................................... 3
2.3.5 Basin C .......................................................................................................................................................... 3
2.3.6 Basin D.......................................................................................................................................................... 4
2.3.7 Basin E .......................................................................................................................................................... 4
2.3.8 Basin F .......................................................................................................................................................... 4
3. STORMWATER BMPS AND ROUTING ......................................................................... 4
3.1 General ..................................................................................................................................................... 5
3.1.1 Silva Cells ...................................................................................................................................................... 5
3.1.2 Pump Vault ................................................................................................................................................... 6
3.1.3 Inlets ............................................................................................................................................................. 6
3.1.4 Pipe Sizing .................................................................................................................................................... 7
3.1.5 Pipe A ........................................................................................................................................................... 8
3.1.6 Pipe B ........................................................................................................................................................... 8
3.1.7 Pipe C ........................................................................................................................................................... 8
3.1.8 Pipe D ........................................................................................................................................................... 8
3.1.9 Pipe E ............................................................................................................................................................ 8
3.1.10 Pipe F ....................................................................................................................................................... 9
3.1.11 Pipe G ....................................................................................................................................................... 9
3.1.12 Pipe H ....................................................................................................................................................... 9
3.1.13 Pipe I ........................................................................................................................................................ 9
3.1.14 Pipe J ........................................................................................................................................................ 9
3.1.15 Pipe K ....................................................................................................................................................... 9
3.2 Detention Calculation ............................................................................................................................... 9
3.3 Operation and Maintenance ................................................................................................................... 10
APPENDIX A--NRCS SOILS REPORT ............................................................................................... 11
APPENDIX B--FEMA FIRM MAP ....................................................................................................... 12
APPENDIX C--PLAN SET ..................................................................................................................... 13
APPENDIX D--HYDROLOGIC CALCULATIONS ............................................................................. 14
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APPENDIX E--HYDRAULIC CALCULATIONS ................................................................................ 15
APPENDIX F—DETENTION CALCULATIONS ............................................................................... 16
APPENDIX G—FOX CROSSING REPORT ....................................................................................... 17
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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 541
Race St, Aspen, Colorado, 81611 (the “Site”). The Site is located in an area with limited access to regional
detention facilities and therefore, facilities providing water quality capture volume and detention have been
designed to treat the majority of runoff for the site. These designs will be discussed in the following sec-
tions.
2. General Site Description
2.1 Existing Condition
The property, was platted as Lot 6 Fox Crossing Subdivision. Based on the topographical improvement
survey, the lot area is +/- 0.14 acres (approximately 6068.38 square feet).
The Site is located in the Fox Crossing area overlooking the Roaring Fork River to the south and Smuggler
Mountain to the east (see Figure 1). The Site generally slopes from east to west at approximately 6.7 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 historic single family
residence.
Figure 1. 541 Race Street, Aspen Vicinity Map
(Source: maps.google.com)
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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.)
Woody Creek Engineering, LLC has referred to the Fox Crossing Master Drainage Plan while developing
designs for this project.
2.2 Proposed Condition
Two historic single family homes will be moved to the lot and conjoined into a new single family home.
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. Water quality treatment is provided. Runoff is detained to meet expected
flow rates per the Fox Crossing Master Plan.
The Site is located on a generally flat area with a steep section of grade on the western edge. Drainage
basins are delineated on Plan Sheet C.1 (Appendix C, C.1). The basins are described in the following sec-
tions. The drainage issues and WQCV treatment BMPs are also described.
2.3 Drainage Basins
Basins A through F 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, below.
Historical peak flows for the 5-year and 100-year events were evaluated for the Site using a time of con-
centration based on the flow path length and slope.
Table 1. Basin Information
BASIN
NO.
TOTAL
BASIN
AREA
(ACRE
S)
IMPER
VIOUS
AREA
(ACRE
S)
%
IMPER
VIOUS
RUNO
FF
COEF.
5YR
RUNO
FF
COEF.
100YR
FLOW
PATH
LENGT
H (FT)
FLOW
PATH
SLOPE
(FT/FT)
PEAK
FLOW
5YR
(CFS)
PEAK
FLOW
100YR
(CFS)
EX1 0.082 0.000 0.0% 0.08 0.35 108.00 0.06 0.015 0.132
EX2 0.057 0.000 0.0% 0.08 0.35 98.00 0.06 0.010 0.093
A1 0.010 0.010 100.0% 0.90 0.96 14.00 0.50 0.029 0.060
A2 0.015 0.015 100.0% 0.90 0.96 14.00 0.50 0.044 0.091
A3 0.002 0.002 100.0% 0.90 0.96 14.00 0.50 0.006 0.012
A4 0.010 0.010 100.0% 0.90 0.96 14.00 0.50 0.029 0.060
A5 0.015 0.015 100.0% 0.90 0.96 14.00 0.50 0.044 0.091
A6 0.001 0.001 100.0% 0.90 0.96 14.00 0.50 0.003 0.006
A7 0.017 0.017 100.0% 0.90 0.96 14.00 0.50 0.050 0.103
C 0.016 0.006 33.9% 0.08 0.35 23.54 0.08 0.004 0.035
D 0.013 0.005 37.4% 0.08 0.35 33.41 0.10 0.003 0.029
E 0.015 0.000 0.8% 0.08 0.35 41.60 0.04 0.003 0.028
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F 0.006 0.000 0.0% 0.08 0.35 13.01 0.13 0.001 0.013
B1 0.014 0.000 0.8% 0.08 0.35 26.05 0.07 0.003 0.031
B2 0.004 0.000 5.8% 0.08 0.35 26.97 0.11 0.001 0.009
Figure 2. Basins
2.3.1 Historical Basin EX1
Historical Basin EX1 is located on the northern half of the lot as shown in Figure 2.
2.3.2 Historical Basin EX2
Historical Basin EX2 is located on the southern half of the lot as shown in Figure 2.
2.3.3 Basin A
Basin A is comprised of seven impervious roof basins: Basins A1, A2, A3, A4, A5, 6 and A7. Basin A1
drains into Basin B1 via drip edge. Basin A2 Drains into Basin C and B2 via drip edge. Basin A3 and A4
drain into Basin E via drip edge. A portion of Basin A5 drains to Basin D, while the rest Drains into Basin
F either directly or via Basin A6. Basin A6 drains into Basin F. Basin A7 drains directly into Pipe E via
downspout. Basin A WQCV and detention requirements are met by the “Silva Cells” described in Section
3.1.1, below. For additional information on the proportions of runoff exiting one basin and entering multiple
basins, such as the case with Basin A5, refer to the inlet description in Section 3.1.2.
2.3.4 Basin B
Basin B is composed of two basins along the southern edge of the lot: Basin B1 and B2. Runoff from Basin
B1 is captured by Inlets C and D and routed to the Silva Cells via Pipe A. Basin B2 runoff is captured by
inlets E and FInlet C, where it is then transported to the Silva Cells via Pipe A.
2.3.5 Basin C
Basin C is composed of the courtwell in the southeast corner of the lot. Basin C runoff is captured by two
trench drains and is routed to the pump vault, where it is pumped into Pipe A and routed to the Silva Cells.
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2.3.6 Basin D
Basin D is composed of the front entrance, the driveway, and a lawn area along the south-eastern edge of
the lot. Runoff from the entrance portion of Basin D is captured by a trench drain and transported to the
pump vault in Basin CSilva Cells via Pipes D, E and K. Runoff from the driveway is captured by a trench
drain along the property line, which routes water to the Silva Cells via Pipe E. The lawn portion of Basin
D is captured by a trench drain in Basin C and Inlet G, where is transferred routed from the Pump Vault to
Pipes A J, K and E and finally routed to the Silva Cells.
2.3.7 Basin E
Basin E is located in the northwest corner of the lot and contains the Silva Cell system. Runoff from Basin
E is captured by Inlets D and A, where it is transferred to the Silva Cells via Pipe A.
2.3.8 Basin F
Basin F is located along the northern property line. Runoff from Basin F is captured by Inlets K and J,
where it is transferred to the Silva Cells via Pipe E and F.
3. Stormwater BMPs and Routing
Low impact design has been utilized where possible to provide WQCV and detention.
9 Principles
1. Consider stormwater quality needs early in the design process.
The architect and owner considered stormwater requirements early in the process.
2. Use the entire site when planning for stormwater quality treatment.
Where possible, overland conveyance was utilized to increase the time stromwater is in contact
with natural systems.
3. Avoid unnecessary impervious areas.
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 where possible.
5. Integrate stormwater quality management and flood control.
Through the use of onsite BMPs stormwater quality management and flood control are integrated
in the project.
6. Develop stormwater quality facilities that enhance the site, the community and the environment.
The site, community and the environment are enhanced by reducing the amount of sediment and
other river pollutants conveyed to the stream system. Hopefully, the use of these stormwater
BMPs on this property and throughout the community will improve the water quality of the Roar-
ing Fork River and its tributaries.
7. Use a treatment train approach.
Where possible a treatment train approach was utilized. For example, much of impervious areas
are conveyed over vegetated grassy areas prior to reaching stormwater BMPs. Theoretically,
more sediment will drop out of the runoff as it is convey through rough grassy areas.
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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.
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 Path 4 Path 5 Path 5 Final Basin
ID WQ BMP ID
A1 B1 Pipe A Silva Cell Outlet Outlet Silva Cell
A2 (1) B2 Pipe A Silva Cell Outlet Outlet Silva Cell
A2 (2) C Pump Vault Pipe AJ to
K to E Silva Cell Outlet Outlet Silva Cell
A3 E Pipe A Silva Cell Outlet Outlet Silva Cell
A4 E Pipe A Silva Cell Outlet Outlet Silva Cell
A5 (1) D Pipe D Pump
VaultPipe K Pipe AE Silva Cell Outlet Outlet Silva Cell
A5 (2) A6 F Pipe F Pipe E Silva Cell Outlet Outlet Silva Cell
A5 (3) F Pipe F Pipe E Silva Cell Outlet Outlet Silva Cell
A6 F Pipe F Pipe E Silva Cell Outlet Outlet Silva Cell
A7 Downspout Pipe E Silva Cell Outlet Outlet Silva Cell
C Pump Vault Pipe A Silva Cell Outlet Outlet Silva Cell
D (1) Pipe D Pump VaultPipe
K
Pipe APipe
E Silva Cell Outlet Outlet Outlet Silva Cell
D (2)
Pipe
APump
Vault
Silva CellPipe J OutletPipe
K Pipe E Silva Cell
Outlet Silva Cell
D (3) Pipe E Silva Cell Outlet Outlet Silva Cell
E Pipe A Silva Cell Outlet Outlet Silva Cell
F Pipe E Silva Cell Outlet Outlet Silva Cell
B1 Pipe A Silva Cell Outlet Outlet Silva Cell
B2 Pipe A Silva Cell Outlet Outlet Silva Cell
NOTE: (#) Denotes multiple flow paths for single basin.
3.1.1 Silva Cells
The Silva Cells treat the entire site. The Silva Cells collect runoff through Pipe A and E. Pipe A and E
discharge into the Silva Cells via 4” perforated PVC pipe. The Silva Cells then discharge via perforated
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PVC pipe serving as an underdrain. The underdrain discharges to the local storm sewer system at the pro-
posed unit rate of Basin Y2 as described in the Fox Crossing Master Drainage Plan and further described
below. Each collection system is described in detail below, followed by a discussion of the detention and
outlet works located in the Silva Cells.
3.1.2 Pump Vault
The pump vault receives flow from Pipe B, and C, and D, resulting in a total tributary flow of
0.126 0.121 cfs. The Vault will be 7 6 ft deep, including a 2 ft cone, a 2 ft solid section and a 2 ft
perforated section, and will be 5 4 ft in diameter. The vault will be equipped with two one Gould
GSP0511 1/2 Munro FS E 1/3 HP Sump Pumps. Each The pump can run at 0.080.121 cfs, result-
ing in a capacity of 0.160.121 cfs. As a result, the pumps are adequate to remove incoming flows
during the 100 year storm. Additional information can be found in Appendix C, sheet C3.1.
3.1.3 Inlets
Inlet flow calculations were conducted using Equation 5-10 from the URMP (Q=CoAo(2gHo)(1/2), where
Co=0.6).
• Each 6-in round grate inlet has a grate area of 9.1 in2 and a sump of 0.1 ft. As a result, each inlet
has a flow capacity of Q=0.09 cfs or 43.2 gpm (Q=0.6*0.06ft2*(2*32.2ft/s2*0.1ft)(1/2)). With a
factor of safety of 2 applied, the capacity is reduced to 21.6 gpm.
• Each 8-in round grate inlet has a grate area of 11.5 in2 and a sump of 0.1 ft. As a result, each inlet
has a flow capacity of Q=0.12 cfs or 54.57 gpm (Q=0.6*11.5/144*(2*32.2ft/s2*0.1ft)(1/2)). With a
factor of safety of 2 applied, the capacity is reduced to 27.3 gpm.
• Each 10-in round grate inlet has a grate area of 21.57 in2 and a sump of 0.1 ft. As a result, each
inlet has a flow capacity of Q=0.23 cfs or 102 gpm (Q=0.6*21.57/144*(2*32.2ft/s2*0.1ft)(1/2)).
With a factor of safety of 2 applied, the capacity is reduced to 51 gpm.
Basin A3 and A4 drain to Basin E via drip edge. Basins A3, A4, and E produce 44.9 gpm of runoff during
the 100-year storm ((0.012cfs+0.060cfs+0.028cfs)*448.8 gpm/cfs). This runoff is captured by Inlet A and
B, resulting in a required flow of 22.44 gpm for each inlet. With flow capacities of 43.227.3 gpm, inlet A
and B (8 in grates) are sufficient in draining the basins.
Basin A1 drains into Basin B1 via drip edge. Basin A1 and B1 produce 40.8 gpm of flow during the 100-
year storm ((0.060cfs+0.031cfs)*448.8 gpm/cfs). This runoff is captured by Inlet C and D, resulting in a
required flow of 20.4 gpm for each inlet. 33 percent of Basin A2 drains into Basin B2 via drip edge, while
the remaining 66 percent drains into the court well. B2 and 33% of Basin A2 produce 20 gpm of flow
during the 100-year storm ((0.091cfs*0.33*+0.009cfs)*448.8 gpm/cfs). This runoff is captured by Inlet
EC. Therefore, Inlet C will be required to convey 40.4 gpm (20.4 gpm + 20 gpm) and Inlet D will be re-
quired to convey 20.4 gpm). With flow capacities of 43.2 27.3 and 51 gpm, inlet C and D (8 in and 10 in
grates) are sufficient in draining the basins.
33 percent of Basin A2 drains into Basin B2 via drip edge, while the remaining 66 percent drains into the
court well. B2 and 33% of Basin A2 produce 20 gpm of flow during the 100-year storm
((0.091cfs*0.33*+0.009cfs)*448.8 gpm/cfs). This runoff is captured by Inlet E. With a flow capacity of
43.2 gpm, inlet E is sufficient in draining the basins.
Inlet E was deleted.
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31.1 percent of Basin D drains into Inlet F and G, while 50.6 % of Basin D drains into the courtwell via
the entry way trench drain and 18.3% is captured in the driveway trench drain. 31.1% of Basin D pro-
duces a flow of 4.0 gpm during the 100-year storm ((0.311*0.029)*448.8 gpm/cfs). With a flow capacity
of 43.2 gpm, inlets F and G are sufficient in draining the basin. The 6-in driveway trench drain extends
the full length of the driveway along the property line, and routes water into Pipe E. The entry way 4-in
trench drain runs north south along the low point of the walkway, and drains into Pipe D.
Basin A6 and 81.4% of Basin A5 drains into Basin F via drip edge. The remaining runoff from Basin A5
is captured by the trench drain in Basin D. These basins produce 41.8 gpm of runoff during the 100-year
storm ((0.013cfs+0.006cfs +(.814*.091cfs))*448.8 gpm/cfs). This runoff is captured by Inlet J and K, re-
sulting in a required flow of 20.9 gpm for each inlet. With flow capacities of 43.2 gpm, inlet J and K are
sufficient in draining the basins.
Basin A7 drains directly into Pipe E via a downspout.
The vault in the court well receives runoff from 66% of Basin A2, 18.6 % of Basin A5, 50.631.1% of Ba-
sin D, and all of Basin C. This results in 0.1230.121 cfs of runoff entering the vault
(0.091cfs*.66+0.091cfs*0.186+0.035cfs+0.029cfs*.5060.311). Basin C is drained by two one 4-in trench
drains. One running along the east side of the courtwell patio, the other through the court well lawn area.
The patio trench drain routes water to Pipe B, while t. Nuisance drainage is collected by inlets F & G
within the planted lawn area. The lawn area routes water to Pipe C.
The above calculations have been provided below in Table 3.
Table 3. Inlet Capacity
*Factor of safety of 2 reduced capacity by 50%/
3.1.4 Pipe Sizing
The pipes were sized using the 100-year flow for the entire property (Q=0.225cfs). A PVC pipe (n=0.011)
with a diameter of 4 inches (D=0.33ft), a minimum slope of 1.5%, will produce a flow of 0.262 cfs at
80% capacity. A PVC pipe (n=0.011) with a diameter of 6 inches (D=0.5ft), a minimum slope of 1.5%,
will produce a flow of 0.794 cfs at 80% capacity. Refer to Appendix E for more information.
The following pipe descriptions have been summarized in Table 4.
Inlet Name Required Flows
(gpm)
Capacity
(gpm)
Inlet A (8 in Round)22.44 27.3
Inlet B (8 in Round)22.44 27.3
Inlet C (8 in Round)40.4 27.3
Inlet D (10 in Round)20.4 51
Inlet E Deleted 20 43.2
Inlet F (4 in Round)Nuisance N/A
Inlet G (4 in Round)Nuisance N/A
Inlet J (6 in Round)20.9 21.6
Inlet K (6 in Round)20.9 21.6
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Table 4. Inlet Pipe Capacity
3.1.5 Pipe A
Pipe A transports much of the properties property’s runoff to the Silva Cells in the northwest corner. Pipe
A has 7 4 inlets: Inlet A, B, C, and D, E, F, and G. In addition, the pump vault in Basin C discharges to
Pipe A. At its terminus, Pipe A discharges into the Silva Cells via a 6” perforated PVC Pipe. The total
tributary runoff rate to Pipe A is 0.3500.230 cfs (including Basin A1, 33% of Basin A2, Basins A3 and
A4, Basins B1 and B2 and Basin E). and itThe pipe has a minimum slope of 1.50%. Therefore a 6-in PVC
pipe is adequate to convey the flow. A profile of Pipe A can be found in Appendix C (Appendix C-3.1).
3.1.6 Pipe B
Pipe B connects the trench drain in the patio portion of the court well to the pump vault. The total tribu-
tary runoff rate to Pipe B is 0.0670.121 cfs (including 66% of Basin A2, 18.6% of Basin A5, 31.1% of
Basin D and 100% of Basin C). and it The pipe has a minimum slope of 2.0%. Therefore a 4-in PVC pipe
is adequate to convey the flow. A profile of Pipe B can be found in Appendix C. (Appendix C-3.1
3.1.7 Pipe C
Pipe C connects the trench drain nuisance inlets (Inlets G & F) in the lawn portion of the court well to the
pump vault. The total tributary runoff rate to Pipe C is 0.028 cfs negligible. and it The pipe has a mini-
mum slope of 2.0%. Therefore a 4-in PVC pipe is adequate to convey the flow. A profile of Pipe C can
be found in Appendix C (Appendix C-3.1).
3.1.8 Pipe D
Pipe D connects the trench drain in Basin D to the pump vaultPipe K. The total tributary runoff rate to
Pipe D is 0.032 cfs (including 50.6% of Basin D and 18.6% of Basin A5). and it The pipe has a minimum
slope of 2.0%. Therefore a 4-in PVC pipe is adequate to convey the flow. A profile of Pipe D can be
found in Appendix C (Appendix C-3.1).
3.1.9 Pipe E
Pipe E transports runoff from the northern portion of the property to the Silva Cells. Pipe E has 2 inlets:
Inlet K and the trench drain located in the driveway. In addition, Pipe F and K discharges to Pipe E. At its
terminus, Pipe E discharges into the Silva Cells via a 6” perforated PVC Pipe. In addition, the pump vault
in Basin C discharges to Pipe A. The total tributary runoff rate to Pipe E is 0.2010.354 cfs (including
81.4% of Basin A5, Basins A6 and A7, 18.3% of Basin D, Basin F as well as Pipe D and Pipe J inflows).
Pipe Name Required Flow (cfs)Capacity (cfs)
Pipe A (6"@ 1.5%)0.23 0.794
Pipe B (4" @ 2.0%)0.121 0.303
Pipe C (4" @ 2.0%)Nuisance Flows 0.303
Pipe D (4" @ 2.0%)0.032 0.303
Pipe E (4" @ 5.0%)0.354 0.478
Pipe F (4" @ 2.0%)0.08 0.303
Pipe G (4" @ 2.0%)Nuisance Flows 0.303
Pipe H (4" @ 2.0%)Nuisance Flows 0.303
Pipe I (6" @ 0.99%)0.568 0.645
Pipe J (2" FM)0.121 0.303
Pipe K (4" @ 2.0%)0.153 0.303
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and it The pipe has a minimum slope of 3.25%. Therefore a 4-in PVC pipe is adequate to convey the
flow. A profile of Pipe E can be found in Appendix C (Appendix C-3.3).
3.1.10 Pipe F
Pipe F connects Inlet J in Basin F to Pipe E. The total tributary runoff rate to Pipe F is 0.080 cfs (includ-
ing 81.4% of Basin A5 and Basin A6). and it The pipe has a minimum slope of 4.68%. Therefore a 4-in
PVC pipe is adequate to convey the flow. A profile of Pipe F can be found in Appendix C (Appendix C-
3.2).
3.1.11 Pipe G
Pipe G connects the deck drain (Integral Deck Dain One) in the northern deck to Pipe A. A profile of Pipe
G can be found in Appendix C (Appendix C-3.2). The deck drain only intercepts nuisance flows, and
therefore a 4-in PVC pipe will be adequate.
3.1.12 Pipe H
Pipe H connects the integral deck drain (Integral Deck Dain Two) in the southern deck to Pipe A. A pro-
file of Pipe H can be found in Appendix C (Appendix C-3.2). The deck drain only intercepts nuisance
flows, and therefore a 4-in PVC pipe will be adequate.
3.1.13 Pipe I
Pipe I serves as an underdrain for the Silva Cell system and discharges to the local storm sewer system.
An orifice plate will be placeds on the outlet of Pipe I, ensuring that discharge is no greater than the his-
torical rate. The total tributary runoff rate to Pipe I is 0.568 cfs and it has a minimum slope of 0.99%.
With a 6-in PVC pipe, this results in an 80% capacity flow rate of 0.645 cfs. Therefore a 6-in pipe will be
adequate. A profile of Pipe I can be found In Appendix C (Appendix C-3.3). For additional information
on the orifice, refer to Section 3.3. Calculations for Pipe I flows can be found in Appendix E.
3.1.14 Pipe J
Pipe J is a 2 in force main used to discharge pumped flows from the pump vault up to Pipe K. Pipe K dis-
charges to Pipe E and finally the Silva Cells. The pump has the capacity to discharge the total pump vault
inflow of 0.121 cfs.
3.1.15 Pipe K
Pipe K connects Pipe J and Pipe D to Pipe E. The total tributary inflow to the pipe is 0.153 cfs. The 4 in
pipe is laid at a minimum of 1.5%, which results in an 80% capacity flowrate of 0.262 cfs. Therefore, a 4
in pipe will be adequate. A profile of Pipe K can be found in Appendix C. Calculations for Pipe K flows
can be found in Appendix E.
3.2 Detention Calculation
The Silva Cells treat water quality and detains flows from all basins. In order to calculated water quality
and detention requirements, WCE calculated the total area of the basins, the impervious area of the basins
and an area time of concentration of the basins. Overall, the basins total area equals 0.139 acres. Values
are provided in Table 5, below.
Table 5. Basin Parameters
BASIN NO. TOTAL BASIN IMPERVIOUS % IMPERV- tc (min)
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AREA (ACRES) AREA (ACRES) IOUS
A1 0.010 0.010 1.00 5
A2 0.015 0.015 1.00 5
A3 0.002 0.002 1.00 5
A4 0.010 0.010 1.00 5
A5 0.015 0.015 1.00 5
A6 0.001 0.001 1.00 5
A7 0.017 0.017 1.00 5
C 0.016 0.006 0.34 5
D 0.013 0.005 0.37 5.04
E 0.015 0.000 0.01 7.43
F 0.006 0.000 0.00 5
B1 0.014 0.000 0.01 5.04
B2 0.004 0.000 0.06 5
TOTAL 0.139
0.082
0.587
Based on an overall imperviousness of 58.7 percent, the WQCV in watershed inches is 0.11 in (see Ap-
pendix D). In terms of volume, the WQCV over the tributary area of 0.139 acres is 55.5 cf (0.139 ac X
43560 sf/ac X 0.1 in X 1 ft / 12 in). Each 1X Silva Cell has a water storage capacity of 2.63 cf (See Ap-
pendix E). As a result, 25 Silva cells over a 204-sf area will be used to detain the WQCV (2.63 cf / 1 cell
* 25 cells = 65.75 cf). Additionally, 2.1 ft of No.2 gravel with a void ratio of 0.25 will be placed under the
Silva Cells, providing an additional 104 cf of storage (200sf * 2.1 ft *.25 = 105 cf). In total, 160cf of stor-
age volume is required (See Appendix E) based on an allowable release rate of 0.189 cfs (described be-
low). The total storage volume of 160.5 cf is greater than the required 160 cf.
The property historically discharges 1760 sf of runoff to the local storm sewer system. In the Fox Cross-
ing Drainage Report, it states that basin Y2 discharges 2.24 cfs during the 100 year storm (See Appendix
G). The Site makes up 1760 sf of basin Y2, therefore the allowable discharge rate is 0.189 cfs
(2.24cfs/.48ac * 1 ac / 43560sf *1760sf = 0.189 cfs). In order to ensure discharge is no greater than 0.189
cfs, the outlet of Pipe I will be fitted with a 1.56 inch orifice plate (0.189 cfs =
0.6*A*(2*32.2ft/s^2*8.579ft)^1/2, A=0.01338 sf, ((0.01338 sf / 3.14)^1/2)*2*12 in = 1.56 in).
The orifice plate is located at the end of Pipe I so that it can be accessed through the sewer vault. In addi-
tion, placing the orifice on the outlet provides additional head so that the flow rate will be closer to the
allowable when the Silva Cells begin to fill.
3.3 Operation and Maintenance
Operation and maintenance recommendations for the Silva Cells were acquired from Section 8.5.3.5
Modular Suspended Pavement System in the URMP.
“Any underdrains must be periodically cleaned by way of the pipe clean out. If it is observed that the sys-
tem is not draining and the soil remains wet for extended periods of time the system may need to be re-
placed. Excavate down to the existing bottom elevation and scrape the bottom layer to remove any fines
in the system.”
In addition, debris must be removed from inlet sumps on quarterly basis.
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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
541 Race
Natural
Resources
Conservation
Service
January 6, 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
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identified each as a specific map unit. Aerial photographs show trees, buildings,
fields, roads, and rivers, all of which help in locating boundaries accurately.
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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.
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9
Custom Soil Resource Report
Soil Map
4339750433977043397904339810433983043398504339870433989043397504339770433979043398104339830433985043398704339890343310 343330 343350 343370 343390 343410 343430 343450 343470 343490 343510 343530 343550
343310 343330 343350 343370 343390 343410 343430 343450 343470 343490 343510 343530 343550
39° 11' 39'' N 106° 48' 51'' W39° 11' 39'' N106° 48' 41'' W39° 11' 34'' N
106° 48' 51'' W39° 11' 34'' N
106° 48' 41'' WN
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84
0 50 100 200 300
Feet
0 15 30 60 90
Meters
Map Scale: 1:1,130 if printed on A landscape (11" x 8.5") sheet.
Soil Map may not be valid at this scale.
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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
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MAP LEGEND MAP INFORMATION
imagery displayed on these maps. As a result, some minor
shifting of map unit boundaries may be evident.
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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
5.7 100.0%
Totals for Area of Interest 5.7 100.0%
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,
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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.
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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
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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
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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
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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
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12
Appendix B--FEMA FIRM Map
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13
Appendix C--Plan Set
4/01/2019
N
10/04/17 DATE OF PUBLICATION
200'400'800'100'
1" = 200'C-0.0
COVER SHEET
03/21/17 PERMIT
541 RACE STREET
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" = 7935'-1.2"
VICINITY MAP 541 RACE541 RACE STREET, ASPEN, CO10/04/17 CHECK SET
10/14/2017
10/4/2017
4/01/2019
I
storm grates
N89°20'00"W 85.41'
N89°20'00"W 85.41'N00°40'00"E71.05'S00°40'00"W71.05'6068.38 sq.ft.+/-
LOT 6
RACE ALLEY20' RIGHT OF WAYB1
A1 A2
A3
A4 A5
A6 A7
C
D
E
F
B2
7933 79337
9
3
5
7934
7
9
3
5
7935
7936 7937
7934
storm grates
N89°20'00"W 85.41'
N89°20'00"W 85.41'N00°40'00"E71.05'S00°40'00"W71.05'6068.38 sq.ft.+/-
LOT 6
RACE ALLEY20' RIGHT OF WAY79337932
7934793679377936793779387937793
67935793479337932793579317932EX1
EX2 7938N
10'20'40'5'
1" = 10'
C-1.0
BASINS
NOTES:
1.EXISTING DRAINAGE BASIN CONSISTS OF LOT.
2.PROPOSED DRAINAGE BASINS ARE DETERMINED
BY TOPOGRAPHY AND STRUCTURE.
HISTORICAL DRAINAGE BASINS PROPOSED DRAINAGE BASINS
HISTORICAL DRAINAGE BASINS
PROPOSED DRAINAGE BASINS
541 RACE541 RACE STREET, ASPEN, CO10/04/17 DATE OF PUBLICATION
03/21/17 PERMIT
CHECK SET10/04/17
10/14/201710/4/2017
4/01/2019
7935
7937.75
storm grates
N89°20'00"W 85.41'
N89°20'00"W
N00°40'00"E71.05'S00°40'00"W71.05'6068.38 sq.ft.+/-
LOT 6
RACE ALLEY20' RIGHT OF WAY79337932
7934793679377936793779357934793379327935793
1
7932-2.0%
4" TRENCH
DRAIN
PIPE B
PIPE C
1X SILVA CELLS
COVER = 2 FT
AREA = 204 SF
PIPE D
PUMP VAULT
-2.0%
-2.1%
TW=7935
TW=7937.33
-12.5%-0.0%6" TRENCH DRAIN
-8.0%
-2.0%
2.0%
7933 79337
9
3
5
7934
7936 7937
7
9
3
5
7935
7934
7932-7
.
7%
-1
2
.
8
%
-13.7
%
FOUR RISERS
FF=7935.1 FT
FF=7937.6 FT
FF=7935 FT
FF=7935.1 FT
FOUR RISERS
FLOW LINE
TBC
INTEGRAL DECK
DRAIN ONE
4" PVC PIPE
IE:7935.01
INTEGRAL DECK
DRAIN TWO
4" PVC PIPE
IE:7935.01
CONNECT TO
TRENCH DRAIN
PIPE E
OUTLET
-1.9%
-2.7%
-2.4%
TW=7927.87GREEN ROOF: 7935
SLOPE > 2%
TW=7937.27
TW=7936
7935TW=7938 TW=7938
TW = 7928.91
PIPE F
PIPE G
PIPE H
6" PERF. PVC PIPE
TD=7937.19
TD=7924.56
TD=7934.85
TOW = 7934.0
PLANTER
-3.8%7933.16
7935.20
7935.48
7935.30
7934.89
7934.17
7933.39
7933.83 7934.70
7935.05
7935.10
7934.85
7934.96
7934.98
7934.85
7937.60
7934.89
7934.89
7935.10
7935.08
7934.98
WO: 7924.77
BW = 7924.55
WO: 7924.77
BW = 7924.55
TW = 7927.87
TW = 7927.87
BW = 7927.58
BW = 7927.87
BW = 7927.87
7934
7937.60
TBC = 7937.19
7937.75
FLOW LINE = 7937.42
7933.00
7935.20 7936.28
7937.60
7937.60 FLOW LINE = 7937.48
TD = 7927.58
7935.43
7935.72
BW = 7929.05
BW = 7929.05
BW = 7929.05
TW = 7927.87
BW = 7927.87
7932.81 7933.47
7934.98
DRAINAGE EASEMENT
(HATCHED)
TIE INTO EXISTING STRUCTURE
1.56 IN ORIFICE
INV = 7919.13 FT
EXISTING STRUCTURE
GR=7928.83 FT
INV IN=7926.45 FT (E)
INV IN = 7919.14 FT (N)
INV OUT = 7919.07 FT (W)
OUTLET
IE=7926.97 FT
7932.65 7932.99INLET
IE=7929.15 FT
TBC = 7937.14
TBC = 7937.37
-3.2%1.6%CURB
TOW:7935.5
TOW:7935.8
79387935.06
7935.06
7935.06
7935.06
-1.04%
-1.04%
7935.06
7935.06
7935.15
7935.26
7935.29
7935.48
7935.09
7933
DO NOT GRADE ON ADJACENT PROPERTY
OTHER SIDE OF SWALE SHOWN FOR REFERNCE
INSTALL TYPE A
CURB AND GUTTER
INSTALL TYPE A
CURB AND
GUTTER
INSTALL TYPE A
CURB AND
GUTTER
TOW = 7940.25
7936 7937
7937
7936
ERRANT VEHICLE
PROTECTION WALL
PROVIDE MINIMUM
2-FT DISTANCE
FROM FACE OF
CURB TO FACE OF
WALL
WIDTH=10-IN
SEE STRUCTURAL
PLANS (SDA-01)
FOR DETAIL
7938.5
7938.5
INLET G
4" ROUND
INLET F
4" ROUND
PIPE J
PIPE K
N
5'10'20'2.5'
1" = 5'
C-2.0
GRADING &
DRAINAGE541 RACEEXISTING TREE REMOVED
EXISTING TREE KEPT
EXISTING CONTOUR
PROPOSED CONTOUR
NOTES:
1.ROOF AREA = 3089 SF
2.TOTAL IMPERVIOUS AREA= 3873 SF.
3.UTILITY LOCATIONS UNKNOWN AND ASSUMED.
REPLACE CURB AND GUTTER IF DAMANGED
DURING CONSTRUCTION.
4.ALL INLETS ARE NDS 6" ROUND GRATES WITH
SPEE-D CATCH BASINS
7910
SPOT ELEVATION XXXX.XX
CONC. = CONCRETE
HP = HIGH POINT
TD = TRENCH DRAIN
UTILITY SERVICE
E=ELECTRIC
UG=UNDERGROUND GAS
SS=SANITARY SEWER
W=WATER
541 RACE STREET, ASPEN, CODATE OF PUBLICATION
03/21/17 PERMIT
STRUCTURE
IMPERVIOUS
PERMIT
2/21/2019
6/28/18
CHANGE ORDER 12/21/19
1/11/20182/21/2018
4/01/2019
PROPOSED SURFACE
7900.00
7910.00
7920.00
7930.00
7940.00
7950.00
7960.00
0+00.00
0+25.00 0+50.00
0+75.00
7915.00
7920.00
7930.00
7940.00
0+00.00
0+25.00
0+29.90
PIPE B
4"PVC
2% SLOPE
TRENCH DRAIN
PIPE C
4"PVC
2% SLOPE
STA:0+10.57
ELEV:7924.56
STA:0+22.42
ELEV:7927.58
STA:0+09.79
ELEV:7935.06
STA:0+07.93
ELEV:7921.92
2 MUNRO FS E 1
3
HP SUMP PUMPS
FLOAT
SWITCHES AT
7922.04
STA:0+07.94
ELEV:7918.08
STA:0+07.94
ELEV:7920.99
STA:0+03.94
ELEV:7918.08
PIPE J
2" FORCE MAIN
CONNECT INLETS F AND G
MINIMUM CONNECTING PIPES
SHALL BE SLOPED A MINIMUM
OF 2%
C-3.1
PROFILES &
CROSS-SECTIONS
COURTWELL PROFILE AND PUMP
VAULT INCLUDING PIPE B,C,D
PIPE A PROFILE
NOTES:
1.TRENCH DRAIN IS ZURN Z-706 WITH HEAVY DUTY
DUCTILE IRON SLOTTED GRATE - TRAFFIC RATED
SEE DETAILS C-4.0.
2.INLETS AND INLET GRATES ARE NDS 9" CATCH
BASIN SERIES AND NDS 980-9" SQ. GRATES. SEE
DETAILS C-4.0.
DATE OF PUBLICATION
03/21/17 PERMIT541 RACE541 RACE STREET, ASPEN, COCHECK SET
2/21/19
10/04/17
2/21/19 CHANGE ORDER 1
1/11/20182/21/2018
4/01/2019
7910.00
7920.00
7930.00
7940.00
7950.00
7960.00
0+00.00 0+15.00
7900.00
7910.00
7920.00
7930.00
7940.00
7950.00
7960.00
0+00.00 0+21.00
7900.00
7910.00
7920.00
7930.00
7940.00
7950.00
7960.00
0+00.00 0+21.00
7930.00
7940.00
0+00.00
0+25.00
0+40.00
C-3.2
PROFILES &
CROSS-SECTIONS
PIPE F PROFILE PIPE H PROFILE
PIPE G PROFILE
DATE OF PUBLICATION
03/21/17 PERMIT541 RACE541 RACE STREET, ASPEN, COCHECK SET
2/21/19
10/04/17
PIPE K PROFILE
CHANGE ORDER 12/21/19
1/11/20182/21/2018
4/01/2019
7900.00
7910.00
7920.00
7930.00
7940.00
7950.00
7960.00
0+00.00
0+25.00 0+50.00 0+75.00
0+76.69
PROPOSED SURFACE
7915.00
7920.00
7930.00
0+00.00
0+25.00 0+50.00
0+60.00
STA:0+17.03
ELEV:7926.76
STA:0+00.00
ELEV:7926.97
STA:0+00.00
ELEV:7928.83
STA:0+00.00
ELEV:7930.22
STA:0+58.72
ELEV:7919.13
STA:0+00.00
ELEV:7926.76
C-3.3
PROFILES &
CROSS-SECTIONS
PIPE E PROFILE NOTES:
1.TRENCH DRAIN IS ZURN Z-706 WITH HEAVY DUTY
DUCTILE IRON SLOTTED GRATE - TRAFFIC RATED
SEE DETAILS C-4.0.
2.INLETS AND INLET GRATES ARE NDS 9" CATCH
BASIN SERIES AND NDS 980-9" SQ. GRATES. SEE
DETAILS C-4.0.
PIPE I PROFILE
DATE OF PUBLICATION
03/21/17 PERMIT541 RACE541 RACE STREET, ASPEN, COCHECK SET
2/21/19
10/04/17
2/21/19 CHANGE ORDER 1
1/11/20182/21/2018
4/01/2019
7935
7935.50
TW =
7928.91
7935
TW = 7928.91
7935.06
7935.06
7935.06
7935.06
-1.04%
-1.04%
7935.06
7935.06
N
5'10'20'2.5'
1" = 5'
C-4.0
UTILITIES
DATE OF PUBLICATION
03/21/17 PERMIT541 RACE541 RACE STREET, ASPEN, COPERMIT
10/04/17
4/12/18
1/11/20182/21/2018
4/01/2019
TRENCH DRAIN DETAIL CATCH BASIN AND GRATE DETAIL
DECK DRAIN SILVA CELL DETAIL
C-5.1
DETAILS
DATE OF PUBLICATION
03/21/17 PERMIT541 RACE541 RACE STREET, ASPEN, CO2'4'8'1'
SCALE: 1" = 2'
CURB AND GUTTER DETAIL
CHECK SET
10/04/17
10/04/17
10/14/201710/4/2017
4/01/2019
C-5.2
DETAILS
SEDIMENT FENCE DETAIL
TRACK PAD DETAIL
DATE OF PUBLICATION
03/21/17 PERMIT541 RACE541 RACE STREET, ASPEN, COORIFICE PLATE DETAIL
PUMP DETAIL
PERMIT
10/04/17
4/12/18
2/21/19 CHANGE ORDER 1
CURB AND GUTTER DETAIL
GRATE DETAIL
1/11/20182/21/2018
4/01/2019
I
RACE ALLEY20' RIGHT OF WAYTRACK PAD18' X 5'N
5'10'20'2.5'
1" = 5'
C-6.0
SEDIMENT AND
EROSION
CONTROL
DATE OF PUBLICATION
03/21/17 PERMIT541 RACE541 RACE STREET, ASPEN, COCHECK SET
10/04/17
10/04/17
10/14/201710/4/2017
4/01/2019
14
Appendix D--Hydrologic Calculations
4/01/2019
City of Aspen Urban Runoff Management Plan
Chapter 8 – Water Quality 8-30 Rev 11/2014
Figure 8.13 Aspen Water Quality Capture Volume
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100WQCV (watershed-inches) Effective Imperviousness of Tributary Area to BMP (percent)
WQCV
SF
4/01/2019
15
Appendix E--Hydraulic Calculations
4/01/2019
Channel Report
Hydraflow Express Extension for Autodesk® AutoCAD® Civil 3D® by Autodesk, Inc.Friday, Mar 1 2019
4in @ 2%
Circular
Diameter (ft) = 0.33
Invert Elev (ft) = 100.00
Slope (%) = 2.00
N-Value = 0.011
Calculations
Compute by: Q vs Depth
No. Increments = 10
Highlighted
Depth (ft) = 0.26
Q (cfs) = 0.303
Area (sqft) = 0.07
Velocity (ft/s) = 4.12
Wetted Perim (ft) = 0.73
Crit Depth, Yc (ft) = 0.30
Top Width (ft) = 0.26
EGL (ft) = 0.53
0 1
Elev (ft)Section
99.75
100.00
100.25
100.50
100.75
101.00
Reach (ft)
4/01/2019
Channel Report
Hydraflow Express Extension for Autodesk® AutoCAD® Civil 3D® by Autodesk, Inc.Friday, Mar 1 2019
4 in @ 5 percent
Circular
Diameter (ft) = 0.33
Invert Elev (ft) = 100.00
Slope (%) = 5.00
N-Value = 0.011
Calculations
Compute by: Q vs Depth
No. Increments = 10
Highlighted
Depth (ft) = 0.26
Q (cfs) = 0.478
Area (sqft) = 0.07
Velocity (ft/s) = 6.52
Wetted Perim (ft) = 0.73
Crit Depth, Yc (ft) = 0.33
Top Width (ft) = 0.26
EGL (ft) = 0.92
0 1
Elev (ft)Section
99.75
100.00
100.25
100.50
100.75
101.00
Reach (ft)
4/01/2019
Channel Report
Hydraflow Express Extension for Autodesk® AutoCAD® Civil 3D® by Autodesk, Inc.Friday, Mar 1 2019
6in @ 0.99%
Circular
Diameter (ft) = 0.50
Invert Elev (ft) = 100.00
Slope (%) = 0.99
N-Value = 0.011
Calculations
Compute by: Q vs Depth
No. Increments = 10
Highlighted
Depth (ft) = 0.40
Q (cfs) = 0.645
Area (sqft) = 0.17
Velocity (ft/s) = 3.83
Wetted Perim (ft) = 1.11
Crit Depth, Yc (ft) = 0.41
Top Width (ft) = 0.40
EGL (ft) = 0.63
0 1
Elev (ft)Section
99.75
100.00
100.25
100.50
100.75
101.00
Reach (ft)
4/01/2019
Channel Report
Hydraflow Express Extension for Autodesk® AutoCAD® Civil 3D® by Autodesk, Inc.Friday, Mar 1 2019
6in @ 1.5%
Circular
Diameter (ft) = 0.50
Invert Elev (ft) = 100.00
Slope (%) = 1.50
N-Value = 0.011
Calculations
Compute by: Q vs Depth
No. Increments = 10
Highlighted
Depth (ft) = 0.40
Q (cfs) = 0.794
Area (sqft) = 0.17
Velocity (ft/s) = 4.71
Wetted Perim (ft) = 1.11
Crit Depth, Yc (ft) = 0.45
Top Width (ft) = 0.40
EGL (ft) = 0.75
0 1
Elev (ft)Section
99.75
100.00
100.25
100.50
100.75
101.00
Reach (ft)
4/01/2019
Silva Cell Volumes from manufacturer
4/01/2019
16
Appendix F—Detention Calculations
4/01/2019
Project:
Basin ID:
Design Information (Input):Design Information (Input):
Catchment Drainage Imperviousness Ia = 58.70 percent Catchment Drainage Imperviousness Ia = 58.70 percent
Catchment Drainage Area A = 0.140 acres Catchment Drainage Area A = 0.140 acres
Predevelopment NRCS Soil Group Type = B A, B, C, or D Predevelopment NRCS Soil Group Type = B A, B, C, or D
Return Period for Detention Control T = 5 years (2, 5, 10, 25, 50, or 100) Return Period for Detention Control T = 100 years (2, 5, 10, 25, 50, or 100)
Time of Concentration of Watershed Tc = 5.00 minutes Time of Concentration of Watershed Tc = 5.00 minutes
Allowable Unit Release Rate q = 1.214 cfs/acre Allowable Unit Release Rate q = 1.214 cfs/acre
One-hour Precipitation P1 = 0.64 inches One-hour Precipitation P1 = 1.23 inches
Design Rainfall IDF Formula i = C1* P1/(C2+Tc)^C3 Design Rainfall IDF Formula i = C1* P1/(C2+Tc)^C3
Coefficient One C1 = 88.80 Coefficient One C1 = 88.80
Coefficient Two C2 = 10 Coefficient Two C2 = 10
Coefficient Three C3 = 1.052 Coefficient Three C3 = 1.052
Determination of Average Outflow from the Basin (Calculated):Determination of Average Outflow from the Basin (Calculated):
Runoff Coefficient C = 0.40 Runoff Coefficient C = 0.56
Inflow Peak Runoff Qp-in = 0.184 cfs Inflow Peak Runoff Qp-in = 0.50 cfs
Allowable Peak Outflow Rate Qp-out =0.170 cfs Allowable Peak Outflow Rate Qp-out =0.170 cfs
Mod. FAA Minor Storage Volume = 8 cubic feet Mod. FAA Major Storage Volume = 160 cubic feet
Mod. FAA Minor Storage Volume = 0.000 acre-ft Mod. FAA Major Storage Volume = 0.004 acre-ft
1 <- Enter Rainfall Duration Incremental Increase Value Here (e.g. 5 for 5-Minutes)
Rainfall Rainfall Inflow Adjustment Average Outflow Storage Rainfall Rainfall Inflow Adjustment Average Outflow Storage
Duration Intensity Volume Factor Outflow Volume Volume Duration Intensity Volume Factor Outflow Volume Volume
minutes inches / hr acre-feet "m" cfs acre-feet acre-feet minutes inches / hr acre-feet "m" cfs acre-feet acre-feet
(input)(output) (output) (output) (output) (output) (output) (input) (output) (output) (output) (output) (output) (output)
0 0.00 0.000 0.00 0.00 0.000 0.000 0 0.00 0.000 0.00 0.00 0.000 0.000
1 4.56 0.000 1.00 0.17 0.000 0.000 1 8.77 0.001 1.00 0.17 0.000 0.001
2 4.16 0.001 1.00 0.17 0.000 0.000 2 8.00 0.002 1.00 0.17 0.000 0.001
3 3.83 0.001 1.00 0.17 0.001 0.000 3 7.35 0.002 1.00 0.17 0.001 0.002
4 3.54 0.001 1.00 0.17 0.001 0.000 4 6.80 0.003 1.00 0.17 0.001 0.002
5 3.29 0.001 1.00 0.17 0.001 0.000 5 6.33 0.003 1.00 0.17 0.001 0.002
6 3.08 0.001 0.92 0.16 0.001 0.000 6 5.91 0.004 0.92 0.16 0.001 0.003
7 2.89 0.002 0.86 0.15 0.001 0.000 7 5.54 0.004 0.86 0.15 0.001 0.003
8 2.72 0.002 0.81 0.14 0.002 0.000 8 5.22 0.005 0.81 0.14 0.002 0.003
9 2.57 0.002 0.78 0.13 0.002 0.000 9 4.93 0.005 0.78 0.13 0.002 0.003
10 2.43 0.002 0.75 0.13 0.002 0.000 10 4.67 0.005 0.75 0.13 0.002 0.003
11 2.31 0.002 0.73 0.12 0.002 0.000 11 4.44 0.005 0.73 0.12 0.002 0.003
12 2.20 0.002 0.71 0.12 0.002 0.000 12 4.23 0.005 0.71 0.12 0.002 0.003
13 2.10 0.002 0.69 0.12 0.002 0.000 13 4.03 0.006 0.69 0.12 0.002 0.004
14 2.01 0.002 0.68 0.12 0.002 0.000 14 3.86 0.006 0.68 0.12 0.002 0.004
15 1.92 0.002 0.67 0.11 0.002 0.000 15 3.70 0.006 0.67 0.11 0.002 0.004
16 1.85 0.002 0.66 0.11 0.002 0.000 16 3.55 0.006 0.66 0.11 0.002 0.004
17 1.77 0.002 0.65 0.11 0.003 0.000 17 3.41 0.006 0.65 0.11 0.003 0.004
18 1.71 0.002 0.64 0.11 0.003 0.000 18 3.28 0.006 0.64 0.11 0.003 0.004
19 1.64 0.002 0.63 0.11 0.003 0.000 19 3.16 0.006 0.63 0.11 0.003 0.004
20 1.59 0.002 0.63 0.11 0.003 0.000 20 3.05 0.007 0.63 0.11 0.003 0.004
21 1.53 0.002 0.62 0.11 0.003 -0.001 21 2.95 0.007 0.62 0.11 0.003 0.004
22 1.48 0.003 0.61 0.10 0.003 -0.001 22 2.85 0.007 0.61 0.10 0.003 0.004
23 1.44 0.003 0.61 0.10 0.003 -0.001 23 2.76 0.007 0.61 0.10 0.003 0.004
24 1.39 0.003 0.60 0.10 0.003 -0.001 24 2.67 0.007 0.60 0.10 0.003 0.004
25 1.35 0.003 0.60 0.10 0.004 -0.001 25 2.59 0.007 0.60 0.10 0.004 0.003
26 1.31 0.003 0.60 0.10 0.004 -0.001 26 2.52 0.007 0.60 0.10 0.004 0.003
27 1.27 0.003 0.59 0.10 0.004 -0.001 27 2.45 0.007 0.59 0.10 0.004 0.003
28 1.24 0.003 0.59 0.10 0.004 -0.001 28 2.38 0.007 0.59 0.10 0.004 0.003
29 1.20 0.003 0.59 0.10 0.004 -0.001 29 2.31 0.007 0.59 0.10 0.004 0.003
30 1.17 0.003 0.58 0.10 0.004 -0.001 30 2.25 0.007 0.58 0.10 0.004 0.003
31 1.14 0.003 0.58 0.10 0.004 -0.001 31 2.20 0.007 0.58 0.10 0.004 0.003
32 1.11 0.003 0.58 0.10 0.004 -0.002 32 2.14 0.007 0.58 0.10 0.004 0.003
33 1.09 0.003 0.58 0.10 0.004 -0.002 33 2.09 0.007 0.58 0.10 0.004 0.003
34 1.06 0.003 0.57 0.10 0.005 -0.002 34 2.04 0.007 0.57 0.10 0.005 0.003
35 1.04 0.003 0.57 0.10 0.005 -0.002 35 1.99 0.008 0.57 0.10 0.005 0.003
36 1.01 0.003 0.57 0.10 0.005 -0.002 36 1.95 0.008 0.57 0.10 0.005 0.003
37 0.99 0.003 0.57 0.10 0.005 -0.002 37 1.90 0.008 0.57 0.10 0.005 0.003
38 0.97 0.003 0.57 0.10 0.005 -0.002 38 1.86 0.008 0.57 0.10 0.005 0.003
39 0.95 0.003 0.56 0.10 0.005 -0.002 39 1.82 0.008 0.56 0.10 0.005 0.003
40 0.93 0.003 0.56 0.10 0.005 -0.002 40 1.78 0.008 0.56 0.10 0.005 0.002
41 0.91 0.003 0.56 0.10 0.005 -0.003 41 1.75 0.008 0.56 0.10 0.005 0.002
42 0.89 0.003 0.56 0.10 0.006 -0.003 42 1.71 0.008 0.56 0.10 0.006 0.002
43 0.87 0.003 0.56 0.09 0.006 -0.003 43 1.68 0.008 0.56 0.09 0.006 0.002
44 0.86 0.003 0.56 0.09 0.006 -0.003 44 1.64 0.008 0.56 0.09 0.006 0.002
45 0.84 0.003 0.56 0.09 0.006 -0.003 45 1.61 0.008 0.56 0.09 0.006 0.002
46 0.82 0.003 0.55 0.09 0.006 -0.003 46 1.58 0.008 0.55 0.09 0.006 0.002
47 0.81 0.003 0.55 0.09 0.006 -0.003 47 1.55 0.008 0.55 0.09 0.006 0.002
48 0.79 0.003 0.55 0.09 0.006 -0.003 48 1.52 0.008 0.55 0.09 0.006 0.002
49 0.78 0.003 0.55 0.09 0.006 -0.003 49 1.50 0.008 0.55 0.09 0.006 0.002
50 0.77 0.003 0.55 0.09 0.006 -0.003 50 1.47 0.008 0.55 0.09 0.006 0.002
51 0.75 0.003 0.55 0.09 0.007 -0.004 51 1.45 0.008 0.55 0.09 0.007 0.001
52 0.74 0.003 0.55 0.09 0.007 -0.004 52 1.42 0.008 0.55 0.09 0.007 0.001
53 0.73 0.003 0.55 0.09 0.007 -0.004 53 1.40 0.008 0.55 0.09 0.007 0.001
54 0.72 0.003 0.55 0.09 0.007 -0.004 54 1.37 0.008 0.55 0.09 0.007 0.001
55 0.70 0.003 0.55 0.09 0.007 -0.004 55 1.35 0.008 0.55 0.09 0.007 0.001
56 0.69 0.003 0.54 0.09 0.007 -0.004 56 1.33 0.008 0.54 0.09 0.007 0.001
57 0.68 0.003 0.54 0.09 0.007 -0.004 57 1.31 0.008 0.54 0.09 0.007 0.001
58 0.67 0.003 0.54 0.09 0.007 -0.004 58 1.29 0.008 0.54 0.09 0.007 0.001
59 0.66 0.003 0.54 0.09 0.007 -0.004 59 1.27 0.008 0.54 0.09 0.007 0.001
60 0.65 0.003 0.54 0.09 0.008 -0.005 60 1.25 0.008 0.54 0.09 0.008 0.000
Mod. FAA Minor Storage Volume (cubic ft.) = 8 Mod. FAA Major Storage Volume (cubic ft.) = 160
Mod. FAA Minor Storage Volume (acre-ft.) = 0.0002 Mod. FAA Major Storage Volume (acre-ft.) = 0.0037
Determination of MAJOR Detention Volume Using Modified FAA Method
(For catchments less than 160 acres only. For larger catchments, use hydrograph routing method)
(NOTE: for catchments larger than 90 acres, CUHP hydrograph and routing are recommended)
UDFCD DETENTION BASIN VOLUME ESTIMATING WORKBOOK Version 2.34, Released November 2013
Determination of MINOR Detention Volume Using Modified FAA Method
DETENTION VOLUME BY THE MODIFIED FAA METHOD
541 RACE
SILVA CELL
SILVA CELL, Modified FAA 3/2/2017, 10:42 AM
4/01/2019
Project:
Basin ID:
UDFCD DETENTION BASIN VOLUME ESTIMATING WORKBOOK Version 2.34, Released November 2013
DETENTION VOLUME BY THE MODIFIED FAA METHOD
541 RACE
SILVA CELL
0
0.001
0.002
0.003
0.004
0.005
0.006
0.007
0.008
0.009
0 10 20 30 40 50 60 70Volume (acre-feet)Duration (Minutes)
Inflow and Outflow Volumes vs. Rainfall Duration
Minor Storm Inflow Volume Minor Storm Outflow Volume Minor Storm Storage Volume Major Storm Inflow Volume Major Storm Outflow Volume Major Storm Storage Volume
SILVA CELL, Modified FAA 3/2/2017, 10:42 AM
4/01/2019
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Appendix G—Fox Crossing Report
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