HomeMy WebLinkAbout01-VGC Drainage Report 8-21-15.pdf ii
A. INTRODUCTION……………………………………………………………………….1
B. METHODOLOGY………………………………………………………………………1
C. EXISTING HYDROLOGY……………………………………………………………..2
D. PROPOSED HYDROLOGY……………………………………………………………3
E. HYDROLOGICAL ANALYSIS AND CONCLUSION……………………………….3
APPENDICIES
APPENDIX A – FIGURES AND TABLES
APPENDIX B – HYDROLOGIC COMPUTATIONS AND SYSTEM ANALYSIS
APPENDIX C – STORM WATER QUALITY INFORMATION
APPENDIX D – REFERENCED SUPPORTING DOCUMENTS
1
A. INTRODUCTION
This Drainage Report has been prepared for the Town of Vail to evaluate the proposed hydrology
for the “Vail Golf and Nordic Clubhouse Remodel” (“project site”) located in Vail, Colorado as shown on
Appendix A Figure 1. The site address is 1775 Sunburst Drive, located in SUNBURST FILING 3 LOT:
3 and VAIL VILLAGE FILING 8 TRACT: A and B.
The intent of this report is to evaluate the anticipated post-development discharge rates from only
the “project site” remodel improvements which are depicted on the 100% Construction Plans dated
7/31/15. The 10, 25 and 100-year rainfall storm events, along with anticipated snowmelt run-offs will be
evaluated to determine if the proposed stormwater system and grass drainage swale can safely
accommodate these anticipated runoff rates, without causing damage to the surrounding infrastructure
according to the Town of Vail Code.
The scope of this report was limited to only analyze the drainage alternations for the “project site”
improvements shown on Figure 1 in Appendix A, since we feel there are only minor alterations from the
existing and proposed site configurations for the proposed remodel project. It is understood that the
proposed improvements are altering the “project site” minor drainage basin patterns, but ultimately the
overall major drainage basin’s runoff should be similar. It will be assumed that all other existing runoff
within the golf course and neighboring properties will follow historical patterns and will not be evaluated
in this report due to the drainage study scope limitations.
Limited off-site drainage information was provided from the “Golf Course Roads Project
Drainage Report for Town of Vail” dated January 1995 prepared by SGM, Inc., and visual site
observations. See Appendix D for report.
B. METHODOLOGY
Due to the urban nature and the small size of the individual sub-basins within the “project site”
study area, it was determined that the rainfall run-off would be analyzed using the Rational Method on the
provided Excel spreadsheets based upon the Urban Storm Discharge Criteria Manual. Modifications as
recommended in the Urban Storm Discharge Criteria Manual published by the Urban Drainage and
Flood Control District, Denver, Colorado in June 2001 have also been adopted. The stormwater
infrastructure and ditch hydrological capacities were analyzed using the Hydraflow Express Extension for
Autodesk AutoCAD Civil 3D software.
Hydrologic soil group information was based upon the previous soils report information and from
the Natural Resource Conservation Service (NRCS), which the soil classification is assumed to be
Hydraulic Type-B. Storm data information was based from the Town of Vail Code, Chapter 10, Section
K.
Curve number information obtained from the NRCS TR-55 Method was used to compute
composite curve numbers based on soil type and percentage of areas within the sub-basins. Runoff
coefficients used for calculations can be found in Appendix A Tables 1 & 2.
2
C. EXISTING HYDROLOGY
Drainage from the Southerly Mountainside and Off-Site Basin Area
The off-site drainage from the mountainside south of the “project site” has historically flooded
the southwesterly parking lot and the original 18th hole area for this site. The worst of this flooding has
historically occurred during the spring snowmelt runoff. This runoff comes down from the southerly
mountainside, converges in a roadside ditch, and then crosses underneath Sunburst Drive in three 18”
CMP culverts. The runoff is directed towards the golf course property down a large landscaped swale,
running between Lot 4 and Lot 5 southeast of the “project site”. It is understood that most of this runoff is
then diverted and conveyed by the golf course service gravel road towards the southwesterly portion of
the parking lot and original 18th hole area.
Based upon the “Golf Course Roads Project Drainage Report for Town of Vail” dated January
1995 prepared by SGM, Inc., potential 10, 25, and 100-year storm events and snowmelt from the
southerly mountainside basin were calculated at approximately 18 c.f.s., 27 c.f.s. and 64 c.f.s.
respectively. See Appendix D for report.
Drainage from the Project Clubhouse and Parking Lot Area
The majority of the existing parking lot and surrounding basin area runoff drains towards the
2’x3’ inlet near the clubhouse building. This runoff then enters into the stormwater system, which it is
understood that it eventually discharges to a drywell manhole near the driving range area. There was no
formal drainage study information available at this time for the golf course clubhouse and parking lot
area. Potential 25-year storm event runoff estimates for this parking lot basin area based upon the
Rational Method formula is estimated and shown below.
Rainfall Runoff:
Q=CiA
Where:
Qr= Peak Runoff (c.f.s.)
C= Runoff coefficient
i= Avg. rainfall intensity for a duration equal to time of concentration (in/hr)
A= Watershed drainage area (ac.)
Q= (1.008 c.f.s/in-hr-ac.)(0.89)(6.44 in/hr)(1.386 ac.)
Q= 8.01c.f.s.
Snomelt Runoff:
Q = 0.067 c.f.s./ac. (1.386 ac.) = 0.093 c.f.s.
Q(total) = 8.103 c.f.s.
3
D. PROPOSED HYDROLOGY
Drainage from the Southerly Mountainside and Off-Site Basin Area
The “project site” improvements are intended to capture and divert the potential off-site runoff
and 18th hole area and convey it around the easterly side of the golf course clubhouse. The off-site runoff
from the southerly mountainside is proposed to drain across the gravel access road at a 30’ wide concrete
valley pan, which is intended to direct a majority of the runoff towards the proposed grass ditch system.
The runoff is proposed to be conveyed thru a 4.0’ flat bottom (5:1 side slopes) grass ditch system, with
twin 24” ADS-HP-Storm HDPE F.E.S. culverts at the path crossings, eventually discharging to Gore
Creek.
Drainage from the Project Parking Lot and Clubhouse Area
The parking lot and golf course clubhouse building area basin runoffs are proposed to be
collected into a storm sewer system and conveyed across the driving range, where is will be eventually
discharged into the northerly detention pond, as indicated on Figure-2 in Appendix A. The storm sewer
system will be comprised of a 3.0’ concrete valley pan, 2’x3’ inlet storm manholes, roof downspout
system, a Contech CDS3035-6-C Water Quality Manhole (runoff treatment), and 18” diameter ADS-HP-
Storm HDPE pipes.
The site parking lot area will be re-graded to allow for the runoff in Basin 1 to drain towards the
center of the parking lot. It will then flow down the proposed 3.0’ concrete valley pan, ranging from
0.9%-3.0%, and be collected into a 2’x3’ CDOT Type-16 valley inlet at the northerly landscaping island,
as depicted in Figure-2. Additionally, runoff from Basin 2 will be collected into the proposed mountable
curb storm inlet and also act as a safety overflow catchment from Basin 1 during major storm events. Two
other storm inlets are provided to collect runoff from the concrete plaza area in front of the clubhouse
building shown as Basins 3 & 4 in Figure-2. There is a proposed roof downspout system, minor area drain
system, and foundation drain system from the building that collects and conveys into this 18” storm sewer
system near the Water Quality Manhole.
All the anticipated runoff will pass thru a Contech CDS3035-6-C Water Quality Manhole for
treatment and then be conveyed thru the 18” storm pipe system to be discharged into the northerly
detention pond.
All other anticipated stormwater runoff south, east, and north of the golf course clubhouse
building is assumed to drain towards the proposed grass ditch system as shown in Figure-2.
E. HYDROLOGICAL ANALYSIS AND CONCLUSION
The stormsewer infrastructure and ditch system design was analyzed for 10, 25 and 100-year
storm events. Each depicted inlet was assumed to collect 100% of the rainfall and snowmelt runoff. The
storm sewer discharges at each design point can be found in Figure-2 of Appendix A.
After analyzing the proposed stormsewer infrastructure for the “Vail Golf and Nordic Clubhouse
Remodel”, it was determined that the proposed 18” stormsewer drainage system can safely convey the 10
& 25-year runoff events, but there can be possible inlet grate ponding backup and overflow due to inlet
grate capacity limitations for Design Point 1-A in the main parking lot area. This overflow in the parking
lot area would eventually be collected into the next downstream inlet shown at Design Point 2-A in
4
Figure-2. The 100-year runoff event is anticipated to cause inlet ponding and pipe surcharging. Refer to
Appendix B for calculations and pipe capacity.
The Contech CDS3035-6-C Water Quality Manhole will only be able to treat minor storm event
runoffs up to 3.8 c.f.s., but will be able to handle and by-pass major storm events up to 20 c.f.s.
The grass ditch system was analyzed using Autodesk Civil3D 2015 Hydraflow Hydrographs
extension software. It is assumed the peak discharge from the lower basin areas within the “project site”
will be discharged before the arrival of the peak runoff from the off-site southerly mountainside basin
area. Therefore the grass ditch system and two 24” ADS-HP-Storm HDPE F.E.S. crossing culverts will be
analyzed using the provided 10, 25, and 100-year storm events and snowmelt of approximately 18 c.f.s.,
27 c.f.s. and 64 c.f.s. respectively. The hydrological capacity analysis of the ditch system is shown in
Appendix B.
5
REFERENCES
References all criteria, storm water data, and technical information used to support the drainage report.
1. Civil Engineering Reference Manual, Michael R. Lindeburg, PE, Professional Publications, Inc.,
Tenth Edition, 2006
2. Urban Drainage and Flood Control District Drainage Criteria Manual, Volume 1, 2001
http://www.udfcd.org/downloads/down_critmanual_volI.htm
3. Golf Course Roads Project Drainage Report for Town of Vail” dated January 1995 prepared by
SGM, Inc.
4. Town of Vail Code, Chapter 10, Section K
http://www.sterlingcodifiers.com/codebook/index.php?book_id=560
APPENDIX - A
MARCIN ENGINEERING LLCGRAPHIC SCALE(IN FEET)1 inch = 60 ft.1-A
MARCIN ENGINEERING, LLC
P.O. Box 1062, Avon Colorado 81620 (970) 748-0274
www.marcinengineering.com
Table 1
Sub Basin Data
Vail Golf and Nordic Clubhouse Remodel
SUB-BASIN NO. AREA (sqft) AREA (acres) IMPERV area (sqft) % IMP C25 C50 C100
1 51,495 1.1822 42,775 83.07% 0.70 0.72 0.74
2 5,685 0.1305 4,830 84.96% 0.78 0.77 0.79
3 4,785 0.1098 4,285 89.55% 0.83 0.85 0.86
4 2,055 0.0472 1,655 80.54% 0.86 0.88 0.89
5 5,752 0.1320 5,752 100.00% 0.94 0.95 0.96
6 8,510 0.1954 8,510 100.00% 0.94 0.95 0.96
7 5,735 0.1317 5,735 100.00% 0.94 0.95 0.96
Note: Basin area calculations were based from the proposed site plans.
Table 2
Runoff Coefficients, C (from Urban Drainage and Flood Control District Manual)
For Type B NRCS Hydrological Soils Only
%
IMPERVIOUS C25 C50 C100
0 0.25 0.30 0.35
5 0.28 0.33 0.38
10 0.31 0.36 0.40
15 0.33 0.38 0.42
20 0.35 0.40 0.44
25 0.37 0.41 0.46
30 0.39 0.43 0.47
35 0.41 0.44 0.48
40 0.42 0.46 0.50
45 0.44 0.48 0.51
50 0.46 0.49 0.52
55 0.48 0.51 0.54
60 0.51 0.54 0.56
65 0.54 0.57 0.59
70 0.58 0.60 0.62
75 0.62 0.64 0.66
80 0.66 0.68 0.70
85 0.72 0.73 0.75
90 0.78 0.80 0.81
95 0.85 0.87 0.88
100 0.94 0.95 0.96
Note: From UDFCD Vol.1, Ch.5, Pg. RO-11 Section 2.7
MARCIN ENGINEERING, LLC
P.O. Box 1062, Avon Colorado 81620 (970) 748-0274
www.marcinengineering.com
Table 3
Town of Vail 1-Hour Precipitation Values
Return Period (years) 10-Year 25-Year 50-Year 100-Year
Rainfall Depth (inches) 1.70 1.90 2.20 2.40
Note: Rainfall depth was from the Town of Vail Code CH13-10-9-6a.
Table 4
Precipitation and Snow Melt Rates
Vail Golf and Nordic Clubhouse Remodel
Frequency
(years)
Snow Melt
(cfs/acre) Total Acres Flow (cfs)
2 0.040 1.60 0.064
5 0.048 1.60 0.077
6 0.060 1.60 0.096
10 0.062 1.60 0.099
25 0.067 1.60 0.107
50 0.072 1.60 0.115
100 0.0800 1.60 0.128
Note: Snowmelt rates are based from the Town of Vail Code CH13-10-9-6a.
APPENDIX - B
CALCULATED BYSTANDARD FORM SF-3 JOB NODATESTORM DRAINAGE SYSTEM DESIGN PROJECTCHECKED BY(RATIONAL METHOD PROCEDURE) DESIGN STORM1HR PT RAINFALL DEPTH (IN)DESIGN POINTAREA DESIGNAREA (ACRES)CTc (MINUTES)C*AI (IN/HR)Q (CFS)Tc (MINUTES)SUM (C*A)I (IN/HR)Q (CFS)MAX CAPACITY (CFS)Mannings No, nSLOPE (%)PIPE SIZE(IN.)LENGTH(FT)APX. VELOCITY(FPS)Tt (MINUTES)LENGTH (FT)SLOPE (%)CONVEYANCE COEFFAPX. VELOCITY (FPS)Tt (MINUTES)REMARKSOutput to Design Point1-A Basin 1 1.182 0.69 5.00 0.81 5.77 4.7610.18 0.012 0.80 18 37 6.0 0.10Flows thru 18" stormsewer system 2-A2-ABasin 20.1310.785.000.105.770.605.100.915.745.3110.180.0120.8018226.10.06Flows thru 18" stormsewer system3-A3-A Basin 3 0.110 0.83 5.00 0.09 5.77 0.54 5.16 1.00 5.72 5.82 10.22 0.012 0.81 18 51 6.3 0.13Flows thru 18" stormsewer system 4-A4-A Basin 4 0.047 0.86 5.00 0.04 5.77 0.24 5.30 1.04 5.68 6.01 10.22 0.012 0.81 18 43 6.6 0.11Flows thru 18" stormsewer system 5-A4-ABasin 50.1320.945.000.125.770.720.610.0121.006423.10.23Flows thru 18" stormsewer system5-ABasin 6 0.195 0.94 5.00 0.18 5.77 1.071.05 0.012 3.00 6 120 3.1 0.65Assumed to discharge to west drainage swale system 7-ABasin 7 0.132 0.94 5.00 0.12 5.77 0.72Assumed to discharge to landscaping N/A5-ABasins 1-55.411.175.656.688.080.0120.50183966.61.01Approx. Flow at Contech Water Quality MH6-A6-A6.411.175.376.36Approx. Q=6.36 c.f.s. at PondNote: Tc was assumed to be a minimum of 5 mins in accordance with the Urban Drainage and Flood Control District Criteria Manual (UDFCD Vol. 1, Ch. 5, Pg. RO-7, Section 2.4.4)output from AutoCAD Civil 3D SSA ProgramNote: Rainfall Intensity I (IN/HR) was based upon equation RA-3 from the Urban Drainage and Flood Control District Criteria Manual (UDFCD Vol.1, Ch. 4, Pg. RA-6, Section 4.0)Note: Direct runoff flows (Q-CFS) shown above also include anticipated snowmelt rates per Town of Vail Code CH13-10-9-6a. (See Table 4 in Appendix)Note: One Hour Rainfall depth (IN) was based from the Town of Vail Code CH13-10-9-6a. (See Table 3 in Appendix)1.7TRAVEL TIME TO NEXT DOWNSTREAM DES. PT.DIRECT RUNOFFTOTAL RUNOFF PIPE DITCH / ACROSS GROUNDMarcin Engineering120048/21/2015Vail Golf and Nordic Clubhouse RemodelMarcin Engineering10 YEAR
CALCULATED BYSTANDARD FORM SF-3 JOB NODATESTORM DRAINAGE SYSTEM DESIGN PROJECTCHECKED BY(RATIONAL METHOD PROCEDURE) DESIGN STORM1HR PT RAINFALL DEPTH (IN)DESIGN POINTAREA DESIGNAREA (ACRES)CTc (MINUTES)C*AI (IN/HR)Q (CFS)Tc (MINUTES)SUM (C*A)I (IN/HR)Q (CFS)MAX CAPACITY (CFS)Mannings No, nSLOPE (%)PIPE SIZE(IN.)LENGTH(FT)APX. VELOCITY(FPS)Tt (MINUTES)LENGTH (FT)SLOPE (%)CONVEYANCE COEFFAPX. VELOCITY (FPS)Tt (MINUTES)REMARKSOutput to Design Point1-A Basin 1 1.182 0.69 5.00 0.81 6.44 5.3110.18 0.012 0.80 18 37 6.0 0.10Flows thru 18" stormsewer system 2-A2-ABasin 20.1310.785.000.106.440.665.100.916.415.9310.180.0120.8018226.10.06Flows thru 18" stormsewer system3-A3-A Basin 3 0.110 0.83 5.00 0.09 6.44 0.60 5.16 1.00 6.39 6.50 10.22 0.012 0.81 18 51 6.3 0.13Flows thru 18" stormsewer system 4-A4-A Basin 4 0.047 0.86 5.00 0.04 6.44 0.26 5.30 1.04 6.35 6.71 10.22 0.012 0.81 18 43 6.6 0.11Flows thru 18" stormsewer system 5-A4-ABasin 50.1320.945.000.126.440.810.610.0121.006423.10.23Flows thru 18" stormsewer system5-ABasin 6 0.195 0.94 5.00 0.18 6.44 1.201.05 0.012 3.00 6 120 3.1 0.65Assumed to discharge to west drainage swale system 7-ABasin 7 0.132 0.94 5.00 0.12 6.44 0.81Assumed to discharge to landscaping N/A5-ABasins 1-55.411.176.317.468.080.0120.50183966.61.01Approx. Flow at Contech Water Quality MH6-A6-A6.411.176.007.10Approx. Q=7.10 c.f.s. at PondNote: Tc was assumed to be a minimum of 5 mins in accordance with the Urban Drainage and Flood Control District Criteria Manual (UDFCD Vol. 1, Ch. 5, Pg. RO-7, Section 2.4.4)output from AutoCAD Civil 3D SSA ProgramNote: Rainfall Intensity I (IN/HR) was based upon equation RA-3 from the Urban Drainage and Flood Control District Criteria Manual (UDFCD Vol.1, Ch. 4, Pg. RA-6, Section 4.0)Note: Direct runoff flows (Q-CFS) shown above also include anticipated snowmelt rates per Town of Vail Code CH13-10-9-6a. (See Table 4 in Appendix)Note: One Hour Rainfall depth (IN) was based from the Town of Vail Code CH13-10-9-6a. (See Table 3 in Appendix)1.9DITCH / ACROSS GROUNDMarcin Engineering8/21/2015Marcin Engineering12004Vail Golf and Nordic Clubhouse Remodel25 YEARTRAVEL TIME TO NEXT DOWNSTREAM DES. PT.DIRECT RUNOFFTOTAL RUNOFF PIPE
CALCULATED BYSTANDARD FORM SF-3 JOB NODATESTORM DRAINAGE SYSTEM DESIGN PROJECTCHECKED BY(RATIONAL METHOD PROCEDURE) DESIGN STORM1HR PT RAINFALL DEPTH (IN)DESIGN POINTAREA DESIGNAREA (ACRES)CTc (MINUTES)C*AI (IN/HR)Q (CFS)Tc (MINUTES)SUM (C*A)I (IN/HR)Q (CFS)MAX CAPACITY (CFS)Mannings No, nSLOPE (%)PIPE SIZE(IN.)LENGTH(FT)APX. VELOCITY(FPS)Tt (MINUTES)LENGTH (FT)SLOPE (%)CONVEYANCE COEFFAPX. VELOCITY (FPS)Tt (MINUTES)REMARKSOutput to Design Point1-A Basin 1 1.182 0.73 5.00 0.86 8.14 7.0810.18 0.012 0.80 18 37 6.0 0.10Flows thru 18" stormsewer system 2-A2-ABasin 20.1310.795.000.108.140.855.100.968.107.8610.180.0120.8018226.10.06Flows thru 18" stormsewer system3-A3-A Basin 3 0.110 0.86 5.00 0.09 8.14 0.78 5.16 1.06 8.07 8.61 10.22 0.012 0.81 18 51 6.3 0.13Flows thru 18" stormsewer system 4-A4-A Basin 4 0.047 0.89 5.00 0.04 8.14 0.34 5.30 1.10 8.02 8.88 10.22 0.012 0.81 18 43 6.6 0.11Flows thru 18" stormsewer system 5-A4-ABasin 50.1320.965.000.138.141.040.610.0121.006423.10.23Flows thru 18" stormsewer system5-ABasin 6 0.195 0.94 5.00 0.18 8.14 1.511.05 0.012 3.00 6 120 3.1 0.65Assumed to discharge to west drainage swale system 7-ABasin 7 0.132 0.94 5.00 0.12 8.14 1.02Assumed to discharge to landscaping N/A5-ABasins 1-55.411.237.979.848.080.0120.50183966.61.01Approx. Flow at Contech Water Quality MH6-A6-A6.411.237.589.37Approx. Q=9.37 c.f.s. at PondNote: Tc was assumed to be a minimum of 5 mins in accordance with the Urban Drainage and Flood Control District Criteria Manual (UDFCD Vol. 1, Ch. 5, Pg. RO-7, Section 2.4.4) output from AutoCAD Civil 3D SSA ProgramNote: Rainfall Intensity I (IN/HR) was based upon equation RA-3 from the Urban Drainage and Flood Control District Criteria Manual (UDFCD Vol.1, Ch. 4, Pg. RA-6, Section 4.0)Note: Direct runoff flows (Q-CFS) shown above also include anticipated snowmelt rates per Town of Vail Code CH13-10-9-6a. (See Table 4 in Appendix)Note: One Hour Rainfall depth (IN) was based from the Town of Vail Code CH13-10-9-6a. (See Table 3 in Appendix)2.4TRAVEL TIME TO NEXT DOWNSTREAM DES. PT.DIRECT RUNOFFTOTAL RUNOFF PIPE DITCH / ACROSS GROUNDMarcin Engineering120048/21/2015Vail Golf and Nordic Clubhouse RemodelMarcin Engineering100 YEAR
Channel Report
Hydraflow Express Extension for Autodesk® AutoCAD® Civil 3D® by Autodesk, Inc.Thursday, Aug 20 2015
VGC-Proposed Drainage Swale-10 YR
Trapezoidal
Bottom Width (ft) = 4.00
Side Slopes (z:1) = 5.00, 5.00
Total Depth (ft) = 2.00
Invert Elev (ft) = 8235.00
Slope (%) = 1.85
N-Value = 0.030
Calculations
Compute by: Known Q
Known Q (cfs) = 18.00
Highlighted
Depth (ft) = 0.65
Q (cfs) = 18.00
Area (sqft) = 4.71
Velocity (ft/s) = 3.82
Wetted Perim (ft) = 10.63
Crit Depth, Yc (ft) = 0.66
Top Width (ft) = 10.50
EGL (ft) = 0.88
0 5 10 15 20 25 30 35
Elev (ft)Depth (ft)Section
8234.50 -0.50
8235.00 0.00
8235.50 0.50
8236.00 1.00
8236.50 1.50
8237.00 2.00
8237.50 2.50
8238.00 3.00
Reach (ft)
Channel Report
Hydraflow Express Extension for Autodesk® AutoCAD® Civil 3D® by Autodesk, Inc.Thursday, Aug 20 2015
VGC-Proposed Drainage Swale-25 YR
Trapezoidal
Bottom Width (ft) = 4.00
Side Slopes (z:1) = 5.00, 5.00
Total Depth (ft) = 2.00
Invert Elev (ft) = 8235.00
Slope (%) = 1.85
N-Value = 0.030
Calculations
Compute by: Known Q
Known Q (cfs) = 27.00
Highlighted
Depth (ft) = 0.79
Q (cfs) = 27.00
Area (sqft) = 6.28
Velocity (ft/s) = 4.30
Wetted Perim (ft) = 12.06
Crit Depth, Yc (ft) = 0.81
Top Width (ft) = 11.90
EGL (ft) = 1.08
0 5 10 15 20 25 30 35
Elev (ft)Depth (ft)Section
8234.50 -0.50
8235.00 0.00
8235.50 0.50
8236.00 1.00
8236.50 1.50
8237.00 2.00
8237.50 2.50
8238.00 3.00
Reach (ft)
Channel Report
Hydraflow Express Extension for Autodesk® AutoCAD® Civil 3D® by Autodesk, Inc.Thursday, Aug 20 2015
VGC-Proposed Drainage Swale-100 YR
Trapezoidal
Bottom Width (ft) = 4.00
Side Slopes (z:1) = 5.00, 5.00
Total Depth (ft) = 2.00
Invert Elev (ft) = 8235.00
Slope (%) = 1.85
N-Value = 0.030
Calculations
Compute by: Known Q
Known Q (cfs) = 64.00
Highlighted
Depth (ft) = 1.19
Q (cfs) = 64.00
Area (sqft) = 11.84
Velocity (ft/s) = 5.41
Wetted Perim (ft) = 16.14
Crit Depth, Yc (ft) = 1.25
Top Width (ft) = 15.90
EGL (ft) = 1.64
0 5 10 15 20 25 30 35
Elev (ft)Depth (ft)Section
8234.50 -0.50
8235.00 0.00
8235.50 0.50
8236.00 1.00
8236.50 1.50
8237.00 2.00
8237.50 2.50
8238.00 3.00
Reach (ft)
Channel Report
Hydraflow Express Extension for Autodesk® AutoCAD® Civil 3D® by Autodesk, Inc.Thursday, Aug 20 2015
VGC-Proposed 18-inch HDPE Culvert at Design Point 5-A - 10 YR
Circular
Diameter (ft) = 1.50
Invert Elev (ft) = 8229.50
Slope (%) = 0.81
N-Value = 0.012
Calculations
Compute by: Known Q
Known Q (cfs) = 6.68
Highlighted
Depth (ft) = 0.88
Q (cfs) = 6.680
Area (sqft) = 1.08
Velocity (ft/s) = 6.17
Wetted Perim (ft) = 2.62
Crit Depth, Yc (ft) = 1.00
Top Width (ft) = 1.48
EGL (ft) = 1.47
0 1 2 3 4
Elev (ft)Depth (ft)Section
8229.00 -0.50
8229.50 0.00
8230.00 0.50
8230.50 1.00
8231.00 1.50
8231.50 2.00
8232.00 2.50
Reach (ft)
Channel Report
Hydraflow Express Extension for Autodesk® AutoCAD® Civil 3D® by Autodesk, Inc.Thursday, Aug 20 2015
VGC-Proposed 18-inch HDPE Culvert at Design Point 5-A - 25 YR
Circular
Diameter (ft) = 1.50
Invert Elev (ft) = 8229.50
Slope (%) = 0.81
N-Value = 0.012
Calculations
Compute by: Known Q
Known Q (cfs) = 7.46
Highlighted
Depth (ft) = 0.95
Q (cfs) = 7.460
Area (sqft) = 1.18
Velocity (ft/s) = 6.30
Wetted Perim (ft) = 2.77
Crit Depth, Yc (ft) = 1.06
Top Width (ft) = 1.44
EGL (ft) = 1.57
0 1 2 3 4
Elev (ft)Depth (ft)Section
8229.00 -0.50
8229.50 0.00
8230.00 0.50
8230.50 1.00
8231.00 1.50
8231.50 2.00
8232.00 2.50
Reach (ft)
Channel Report
Hydraflow Express Extension for Autodesk® AutoCAD® Civil 3D® by Autodesk, Inc.Thursday, Aug 20 2015
VGC-Proposed 18-inch HDPE Culvert at Design Point 5-A - 100 YR
Circular
Diameter (ft) = 1.50
Invert Elev (ft) = 8229.50
Slope (%) = 0.81
N-Value = 0.012
Calculations
Compute by: Known Q
Known Q (cfs) = 9.84
Highlighted
Depth (ft) = 1.18
Q (cfs) = 9.840
Area (sqft) = 1.49
Velocity (ft/s) = 6.59
Wetted Perim (ft) = 3.28
Crit Depth, Yc (ft) = 1.21
Top Width (ft) = 1.23
EGL (ft) = 1.85
0 1 2 3 4
Elev (ft)Depth (ft)Section
8229.00 -0.50
8229.50 0.00
8230.00 0.50
8230.50 1.00
8231.00 1.50
8231.50 2.00
8232.00 2.50
Reach (ft)
Inlet Report
Hydraflow Express Extension for Autodesk® AutoCAD® Civil 3D® by Autodesk, Inc.Friday, Aug 21 2015
VGC-Inlet 1-A
Grate Inlet
Location = Sag
Curb Length (ft) = -0-
Throat Height (in) = -0-
Grate Area (sqft) = 2.57
Grate Width (ft) = 1.88
Grate Length (ft) = 3.27
Gutter
Slope, Sw (ft/ft) = 0.020
Slope, Sx (ft/ft) = 0.020
Local Depr (in) = -0-
Gutter Width (ft) = 2.00
Gutter Slope (%) = -0-
Gutter n-value = -0-
Calculations
Compute by: Q vs Depth
Max Depth (in) = 6
Highlighted
Q Total (cfs) = 7.00
Q Capt (cfs) = 7.00
Q Bypass (cfs) = -0-
Depth at Inlet (in) = 5.98
Efficiency (%) = 100
Gutter Spread (ft) = 24.90
Gutter Vel (ft/s) = -0-
Bypass Spread (ft) = -0-
Bypass Depth (in) = -0-
APPENDIX - C
TABLE 1
Storm Water Treatment Device
Hydraulic and Storage Capacities
CDS Model
Treatment
Capacity
(cfs)/(L/s)
Minimum Sump
Storage
Capacity
(yd3)/(m3)
Minimum Oil
Storage Capacity
(gal)/(L)
CDS2015-G 0.7 (19.8) 0.5 (0.4) 70 (265)
CDS2015-4 0.7 (19.8) 0.5 (1.4) 70 (265)
CDS2015 0.7(19.8) 1.3 (1.0) 92 (348)
CDS2020 1.1 (31.2) 1.3 (1.0) 131 (496)
CDS2025 1.6 (45.3) 1.3 (1.0) 143 (541)
CDS3020 2.0 (56.6) 2.1 (1.6) 146 (552)
CDS3030 3.0 (85.0) 2.1 (1.6) 205 (776)
CDS3035 3.8 (106.2) 2.1 (1.6) 234 (885)
CDS4030 4.5 (127.4) 5.6 (4.3) 407 (1540)
CDS4040 6.0 (169.9) 5.6 (4.3) 492 (1862)
CDS4045 7.5 (212.4) 5.6 (4.3) 534 (2012)
CDS2020-D 1.1 (31.2) 1.3 (1.0) 131 (495)
CDS3020-D 2.0 (56.6) 2.1 (1.6) 146 (552)
CDS3030-D 3.0 (85.0) 2.1 (1.6) 205 (776)
CDS3035-D 3.8 (106.2) 2.1 (1.6) 234 (885)
CDS4030-D 4.5 (127.4) 4.3 (3.3) 328 (1241)
CDS4040-D 6.0 (169.9) 4.3 (3.3) 396 (1499)
CDS4045-D 7.5 (212.4) 4.3 (3.3) 430 (1627)
CDS5640-D 9.0 (254.9) 5.6 (4.3) 490 (1854)
CDS5653-D 14.0 (396.5) 5.6 (4.3) 599 (2267)
CDS5668-D 19.0 (538.1) 5.6 (4.3) 733 (2774)
CDS5678-D 25.0 (708.0) 5.6 (4.3) 814 (3081)
CDS3030-DV 3.0 (85.0) 2.1 (1.6) 205 (776)
CDS5042-DV 9.0 (254.9) 1.9 (1.5) 294 (1112)
CDS5050-DV 11.0 (311.5) 1.9 (1.5) 367 (1389)
CDS7070-DV 26.0 (736.3) 3.3 (2.5) 914 (3459)
CDS10060-DV 30.0 (849.6) 5.0 (3.8) 792 (2997)
CDS10080-DV 50.0 (1416.0) 5.0 (3.8) 1057 (4000)
CDS100100-DV 64.0 (1812.5) 5.0 (3.8) 1320 (4996)
Area 1.6 acres 31
Weighted C 0.89 (select from Rainfall Data column D)
Tc 5 minutes Particle size 125 microns
CDS Model 3035 (select from pulldown) 3.8 cfs
Diameter CDS Hydraulic Capacity 20.0 cfs
Rainfall
Intensity1
(in/hr)
Percent
Rainfall
Volume1
Cumulative
Rainfall
Volume
Total
Flowrate
(cfs)
Treated
Flowrate
(cfs)
Operating
Rate (%)
Removal
Efficiency
(%)
Incremental
Removal (%)
0.04 28.3% 28.3% 0.06 0.06 1.50 100.0 28.3
0.08 33.1% 61.4% 0.11 0.11 3.00 100.0 33.1
0.12 13.2% 74.6% 0.17 0.17 4.50 100.0 13.2
0.16 8.1% 82.7% 0.23 0.23 6.00 100.0 8.1
0.20 5.2% 87.9% 0.28 0.28 7.49 99.9 5.2
0.24 2.5% 90.4% 0.34 0.34 8.99 99.6 2.5
0.28 1.5% 91.9% 0.40 0.40 10.49 99.3 1.5
0.32 1.1% 93.0% 0.46 0.46 11.99 99.0 1.1
0.36 0.7% 93.7% 0.51 0.51 13.49 98.7 0.7
0.40 0.5% 94.2% 0.57 0.57 14.99 98.4 0.5
0.44 0.7% 94.9% 0.63 0.63 16.49 98.1 0.7
0.48 0.8% 95.7% 0.68 0.68 17.99 97.8 0.7
0.52 0.8% 96.5% 0.74 0.74 19.49 97.5 0.8
0.56 0.2% 96.7% 0.80 0.80 20.99 97.2 0.2
0.60 0.2% 96.9% 0.85 0.85 22.48 96.9 0.2
0.64 0.2% 97.1% 0.91 0.91 23.98 96.6 0.2
0.68 0.2% 97.3% 0.97 0.97 25.48 96.3 0.2
0.72 0.2% 97.6% 1.03 1.03 26.98 96.0 0.2
0.76 0.5% 98.0% 1.08 1.08 28.48 95.7 0.5
0.80 0.5% 98.6% 1.14 1.14 29.98 95.4 0.5
98.4
0.0%
98.6%
98.4%
1 - Based on 10 years of 15-minute rainfall data from NCDC Station 2454 at Eagle FAA Airport, Eagle Co., CO
2 - Reduction due to use of 60-minute data for a site that has a time of concentration less than 30-minutes.
Predicted Net Annual Load Removal Efficiency =
BASED ON AN AVERAGE PARTICLE SIZE OF 125 MICRONS
CDS ESTIMATED NET ANNUAL SOLIDS LOAD REDUCTION
Vail Golf and Nordic Center
Vail, CO
Rainfall Station #
CDS Treatment Capacity
Removal Efficiency Adjustment2 =
Predicted % Annual Rainfall Treated =
BASED ON THE RATIONAL RAINFALL METHOD
APPENDIX - D