HomeMy WebLinkAboutDrainage ReportWA MART 5TORE #3093-00
795 W. Over/and Rd.
Meridian, ID
Drainage Report
January 13, 2011
Prepared by- Pa&ick Holm E.L T.
Reviewedby- Nick Taylor, P.E.
606 Columbia ST NW; Suite 106, Olympia, Washington 95501
(360)786-9500 FAX (360)786-5267 EMAIL: padandapac/androm
"I hereby certify that this Drainage Report for Proposed Walmart Store # 3093-00 at
the southeast corner of Overland Road and Stoddard Road has been prepared by
me or under my supervision and meets minimum standards of the City of Meridian,
Ada County Highway District and normal engineering practice. I understand that
the jurisdiction does not and will not assume liability for the sufficiency, suitability,
or performance of drainage facilities designed by me."
Nicholas D. Taylor, P.E.
Section
DrainageReport.......................................................................
1. Proposed Project Description ........................................
2. Existing Conditions........................................................
3. Infiltration Rates and Soils Report ..................................
4. Sub -Basin Description...................................................
5. Facility Sizing and Downstream Analysis .......................
Appendix A- Figures
Appendix B - Water Quality and Quantity Control Calculations
Appendix C- Geotechnical Report
2
2
4
4
6
6
Drainage Report Meridian, ID
Section 1 -Proposed Project Description.
Parcel Numbers: 87288000084, 87288000014, S1224120900, 51224120950
Total Site Area: 19.75 acres
Zoned: General Retail and Service Commercial Zone — C -G
Site Address: 795 W. Overland Rd
Meridian, ID 83642
Site Location:
The project is located at the southeast corner of W. Overland Road and S. Stoddard Road
in Meridian, ID(See Vicinity Map, Appendix A, Figure 1). Access is from W. Overland
Road and S. Stoddard Road.. Site boundaries include an W. Overland Road to the north,
an existing Lowe's and ICON Credit Union to the east, Bear Creek Residential Subdivision
to the south, and S. Stoddard Road to the west. A Site Plan and Frontage Improvement
Plan are enclosed in Appendix A, as Figures 2 and 3.
Project Overview:
This report accompanies the Site Civil Plans for the construction of a new retail
development. The development will be constructed in two phases and will include
appropriate erosion control measures, clearing, grading, underground utilities, paving, and
construction of a 165,507 SF single story retail sales facility for the first phase. The second
phase will be the development and construction of the outlets, which is not a part of this
project. The project site is approximately 19.75 acres with 0.46 acres of frontage
improvements along S. Stoddard Rd. The on-site improvements have been designed to the
Ada County Highway District (ACHD) Policy Manual, Change Number Two, February 14,
1996(1996 ACHD Manual) as adopted by the City of Meridian. The Stoddard Road
frontage improvements have been designed to the most current ACHD policy manual.
Storm Drainage Improvements:
The site is divided into four different basins for control of stormwater runoff. 17.78 acres
of the site will be impervious, which includes the roof of the proposed retail store. For the
purposes of this drainage report the outlouts have been considered as 100% impervious
surfaces to take a conservative approach regarding future development. Approximately
2.43 acres will be pervious landscaped areas. See Table 1 for post -developed basin area
summary. The runoff from the stormwater that falls on the site will be collected in a
system of catch basins that will convey the runoff in underground pipes to a seepage bed.
PACLAND job #30001053 Page 2
Drainage Report Meridian, ID
The seepage bed will use Stormtech chambers and drain rock to detain runoff. From the
seepage bed, the runoff will receive primary treatment by percolating through a sand filter.
17.78 acres of the site will be impervious, which includes the roof of the proposed retail
store. Approximately 2.43 acres will be pervious landscaped areas. See Table 1 for post -
developed basin area summary.
Table 1: Proposed Basin Areas
Basin
Impervious Surface;
CN 98
Pervious Area;
CN 74
Total Basin
Area
Basin A
6.89
0.91
7.80
Basin B
10.41
0.52
10.93
Basin C
0.48
0.26
0.74
Basin D
0.00
0.74
0.74
Total
17.78
2.43
20.21
Stormwater Treatment:
Stormwater treatment requirements are based on the 1996 ACHD Manual for on-site
treatment. The Stoddard Road frontage improvement stormwater treatment design is based
on the most current ACHD policy manual. The basins include the driveways, drive aisles,
parking areas, sidewalks, roof surface, and landscaped areas. Runoff from these areas will
sheet flow into catch basins that convey water to seepage beds below the pavement.
Runoff will then percolate through ASTM C-33 Filter Sand, which is approved by ACHD
for primary treatment. There is no pretreatment (sand and grease traps) for the seepage
beds on-site. Because there is no pretreatment, the seepage bed is sized 50% larger than
the required design value to account for potential sediment. Additionally, the seepage
beds will have an isolator row to trap suspended solids. Each seepage bed was designed
to detain and treat the 100 -year, 24-hour event. The seepage bed in the
Additional detailed drainage calculations for water quantity and quality will be shown in
Appendix B.
Stormwater Detention:
Due to well -draining soils discovered on-site, all runoff from the 100 -year, 24-hour storm
event will be infiltrated through the bottom of the seepage beds which have a combined
footprint of approximately 29,000 ft. Terracon performed a pilot infiltration test on
December 20, 2011, at each proposed bed location. The observed infiltration rate for
Seepage Bed Awas 9 inches/hour and Seepage Bed B was 15 inches/hour. PACLAND
applied a factor of safety of 3 to each of these infiltration rates and calculated a 3
inches/hour and 5 inches/hour rate, respectively. See Appendix C for the geotechnical
report. The SCS method was used to calculate the design volumes based on the design
infiltration rates. For Seepage Bed C, Terracon gave a preliminary infiltration rate based on
PACLAND Job #30001053 Page 3
Drainage Report Meridian, ID
the geotechnical data of 10 inches/hour. PAC LAND applied a factor of safety of 3 to this
rate resulting in a 3.3 inches/hour design infiltration rate. This rate will be verified by a
field test prior to construction. See Section 5 for detailed description and calculations.
Stormwater Conveyance:
Runoff will sheet flow across the parking and landscaped surfaces, collect in curb and
gutter, then will be conveyed to open grate catch basins in parking areas. Rooftop runoff
will be captured by roof drains and be conveyed directly to the seepage beds. All
captured runoff will be conveyed through Corrugated Polyethylene Pipe(CPEP) smooth
interior/annular exterior. All on-site conveyance grates, structures, pipes and associated
appurtenances are sized to convey the 25 -year, 24-hour event, as prescribed by the 1996
ACHD Policy Manual, as adopted by the City of Meridian. The Stoddard Road frontage
improvements conveyance grates, structures, pipes and associated appurtenances are sized
to convey the 100 -year, 24-hour event per the current ACHD Policy Manual. Conveyance
calculations are further described in detail in Section 5.
Section 2 - Existing conditions.
The project site is currently undeveloped consisting of low to medium coverage
vegetation. The site naturally slopes from the northeast to the southwest and on-site
elevations vary from 2637' to 2624' with the steepest existing slopes of 4:1. Due to curb
and gutter along Overland Road on the north boundary and the Lowe's site to the east
boundary, there is little to no stormwater runon from the north or east. Stoddard Road has
no curb and gutter along the property boundary so stormwater runon flows on to the site
from Stoddard Road along the west boundary. The southern boundary is down gradient of
the site so there is no runon along the southern boundary.
There were no creeks, lakes, ponds, wetlands, ravines, gullies, springs, or other
environmentally sensitive areas discovered onsite or within a quarter mile downstream of
the site.
On-site drainage is contained within the site with the exception of minimal sheet flow at
various locations directed off-site through vegetated groundcover.
Section 3 - Inf►ltration Rates and Soils Report.
A geotechnical report and infiltration tests have been completed by Terracon, and the
report and test data have been included in Appendix C.
Groundwater was not encountered in any of the on-site borings, the maximum bore depth
being 20 feet below ground surface. The geotechnical report by Terracon referenced the
Idaho Department of Water Resources well log lookup tool. Using this tool Terracon
found depths of groundwater ranging from 25-89 feet below the ground surface. Three
PACLAND Job #30001053 Page 4
Drainage Report Meridian, ID
feet of separation from the bottom of the seepage bed to the shallowest documented
groundwater elevation will be maintained at all seepage bed facilities.
Pilot infiltration tests(PITs), also known as large scale infiltration tests, were completed
December 20, 2012 by Terracon in two locations, the vicinity of the proposed north
seepage bed and the vicinity of the proposed south seepage bed. A PIT involves
excavating large pits and then performing a constant head test and a falling head test to
determine infiltration rates. The tests yielded an infiltration rate of 9 in and 15
inches/hour for the north and south respectively. Per Walmart's requirement for infiltration
facilities under parking lots, these infiltration rates were reduced using a factor of safety of
3,0, yielding rates of 3 inches/hour and 5 inches/hour respectively for the north and south
seepage beds.
An infiltration test in accordance with ACHD standards is scheduled for the proposed
seepage bed that will detain the new runoff created by the proposed curb and gutter along
Stoddard Road. For preliminary design, Terracon gave an infiltration rate of 10
inches/hour. PACLAND applied a factor of safety of 3 to this rate resulting in a 3.3
inches/hour design infiltration rate. This rate will be verified by a field test.
PACLAND Job #30001053 Page 5
Drainage Report Meridian, ID
Section 4 - Sub -Basin Description:
The site is divided into four basins (Basins A -D). See Figure 4 in Appendix A
Basin A includes the north portion of the site and approximately half of the building. Basin
B includes the south portion of the site and approximately half of the building. Basin C
includes the western frontage improvements and Stoddard Road. Basin D includes the
landscape strip that runs along the southern boundary line.
Each basin has been divided into smaller sub -basins based on local grading and drainage
capacity. See Table 2 for sub -basin area quantities.
Table 2: Proposed Sub -Basin Areas
Bain
, ,ea. SF>
< e fAc-
A-1
6,116
0.14
A-2
2,002
0.05
A-3
14,114
0.32
A-4
61,893
2.35*
A-5
16,824
0.39
A-6
18,511
0.42
A-7
18,352
0.42
A-8
56,349
1.29
A-9
45,319
1.04
A-10
22,397
0.51
A-11
35,908
0.82
A-12
9,786
0.22
A-13
--
2.56*
A-14
13,702
0.49*
B-1
90,669
2.08
B-2
130,978
3.01
B-3
72,708
1.67
B-4
11,914
0.27
B-5
61,893
1.42
B-6
0.09*
B-7
0.09*
B-8
1.19*
B-9
—
1.95*
B-10
11,576
0.27
B-11
7,729
0.18
B-12
6,905
0.21
B-13
13,824
0.32
-1
20,016
0.46
C-2
13,702
0.31
D-1
32,607
0.75
*Does not equal actual basin area. Roof drains are designed per Walmart standard to
convey a 5 inches/hour intensity storm through a siphonic system. These areas have been
adjusted by keeping the flow of the roof drains constant but adjusting the area based on
the 25 -year 24-hour 10 -min Tc intensity of 2.37 inches/hour.
Section 5 - Facility Sizing
Basin A:
Basin A is approximately 7.80 acres and is located in the north portion of the site. This
basin and the remaining three basins are shown in Figure 4 in Appendix A. There is
approximately 0.91 acres of pervious landscaping throughout the basin. The remaining
acreage is a combination of impervious paved and rooftop surfaces.
PACLAN D job #30001053 Page 6
Drainage Report Meridian, ID
The rooftop area will be conveyed through a siphonic manhole system to the underground
conveyance system. From there, it will be conveyed to the underground seepage bed.
The runoff from the impervious surfaces will be collected by manholes and conveyed
through CPEP to the underground seepage bed. Several small auxiliary vestibules drain
through regular roof drains to the underground conveyance system.
The outlot area of Basin A is assumed to be impervious to provide for the most
conservative calculation of future development.
Basin B is approximately 10.88 acres and is located in the south portion of the site. There
is approximately 0.50 acres of pervious landscaping throughout the basin. The remaining
acreage is a combination of impervious paved and rooftop surfaces.
The rooftop area will be conveyed through a siphonic manhole system to the underground
conveyance system. From there, it will be conveyed to the underground seepage bed.
The runoff from the impervious surfaces will be collected by manholes and conveyed
through CPEP to the underground seepage bed. Several small auxiliary vestibules drain
through regular roof drains to the underground conveyance system.
The outlot area of Basin B is assumed to be impervious to provide for the most
conservative calculation of future development.
Basin C:
Basin C is approximately 0.78 acres and is located in the west portion of the site. There is
approximately 0.28 acres of pervious landscaping throughout the basin. The remaining
acreage is impervious surface.
The runoff from the impervious surface will be collected in curb and gutter and conveyed
to an inlet catch basin. From there; it will be conveyed to a sand and grease trap followed
by a seepage bed.
Basin D:
Basin D is approximately 0.74 acres and is located along the south portion of the site.
Approximately the entire area is pervious landscaping. This area will be vegetated and
will not alter the existing drainage pattern or quantity.
PACLAN D Job #30001053 Page 7
Drainage Report Meridian, ID
Seepage Bed Facilities:
The proposed seepage beds for Basin A and B were sized using Stormshed 3G by
Engenious Sytems, Inc. using the SCS Unit Hydrograph Method. The seepage bed for
Basin C, along Stoddard Road, was sized per the current ACHD Policy Manual and
verified using Stormshed 3G.
Seepage Beds A and B:
Seepage Beds A and B were designed to accommodate the 100 -year 24-hour event. Based
on the Idaho Isopluvial map by National Oceanic and Atmospheric
Administration(NOAA), 2.7 inches/hour was identified as the 100 -year, 24-hour design
precipitation rate. The seepage bed design utilizes the Stormtech MC4500 chamber
system. The specifications and cross section of this system can be found in Appendix B.
The design infiltration rates for Seepage Bed A and B is 3 inches/hour and 5 inches/hour,
respectively, as previously noted in this report.
The storm event information and infiltration data was entered into Stormshed 3G to
determine the appropriate seepage bed volume and footprint. Once this volume was
determined for each seepage bed, Walmart requires that each seepage bed be sized 1500/,
of the design volume to account for sediment buildup and other unanticipated drainage
complications. Because these seepage beds are 150% the size of the required volume,
sand and grease pretreatment has been omitted as allowed by the ACHD policy manual.
Sediment capture will be further supplemented by isolator rows in each seepage bed,
which collect sediment using proprietary devices that can be cleaned. See Table 3 for the
seepage bed design and proposed volumes. Both Seepage Beds A and B will drain more
than 90% of the 100 -year, 24-hour event runoff volume within 24 hours as prescribed by
the ACHD policy manual. The porosity (Stormshed 3G Void Ratio) of the seepage beds
was determined by calculating the volume of storage and dividing it by the total volume.
The outputs from Stormshed 3G are included in Appendix B.
Table 3: On-site Seepage Bed Data
Seepage Bed Infiltration
Required
Proposed Volurrt:
eepage Bed
Rate (in/hr)
Volume (cf)
(cf)
Footprint (sf)
Seepage Bed A 3
32,785
50,140
12,000
Seepage Bed B 5
42,618
65,155
15,680
Seepage Bed C
Seepage Bed C was designed to accommodate the 100 -year, 24-hour event based on the
current ACHD policy manual, which uses the rational method. Terracon gave a
preliminary infiltration rate of 10 inches/hour for Seepage Bed C. A design factor of safety
of 3 has been applied to this preliminary infiltration rate to obtain 3.3 inches/hour. This
data can be seen in Table 4. This infiltration rate will be verified by a field test from
Terracon prior to construction. ACHD has a stormwater calculation sheet to determine the
PACLAND Job #30001053 Page 8
Drainage Report Meridian, ID
stormwater runoff and the subsequent sizing of sand and grease pretreatment and seepage
beds. These calculation sheets can be found in Appendix B.
Table 4: Frontage Improvement Seepage Bed C Data
Seepage Bed
filtration
Design Volume
Proposed V e Bed
12
(in/hr)
(cfl
(cfl ... rint (sfl
Seepage Bed C
3.3
3,915
4,100
1,350
The design of this seepage bed was verified using Stormshed 3G. This seepage bed will
drain more than 90% of the 100 -year, 24-hour event runoff volume within 24 hours as
prescribed by the ACHD policy manual. The porosity (Stormshed 3G Void Ratio) of the
seepage bed was determined by calculating the volume of storage and dividing it by the
total volume. This data is included in Appendix B.
Treatment Facilities:
The stormwater runoff is to be treated using an 18" ASTM C-33 Filter Sand strip below
each Seepage Bed. All facilities meet the infiltration requirements set forth by the previous
and current ACHD policy manuals. Seepage Beds A and B do not have pretreatment
facilities because they are sized 150% of the design volume and are supplemented with
sediment isolator rows. Seepage Bed C, which collects runoff from the Stoddard Road,
will have a 1000 gallon sand and grease trap for pretreatment, and thus does not require
oversizing. This sand and grease trap was sized using the ACHD stormwater calculation
spreadsheet and is included in Appendix B.
Conveyance:
On -Site Conveyance:
Per the 1996 ACHD manual the on-site conveyance system was sized to accommodate the
25 -year 24-hour storm event. This event has a rainfall intensity of 2.37 inches/hour for a
Tc of 10 minutes. Maximum flows for 12", 18" and 24" pipes were calculated using the
Manning equation and the maximum contributing areas for each applicable pipe size was
calculated using these maximum flows and is shown in Table 5.
Table 5: Maximum Pipe Flows and Areas
Pipe Size
(in)
Max Flow, Q
(cfs)
i
es/ho ::
Maximum
0iijilififfillik,
12
2.52
0.95 2.37
1.12
18
7.42
0.95 2.37
3.30
24
15.99
0.95 2.37
7.11
Each basin was tabulated to account for the cumulative contributing sub -basins to that
basin's conveyance system. If the cumulative area exceeded the maximum area for a pipe
PACLAND Job #30001053 Page 9
Drainage Report Meridian, ID
size, that section of the conveyance system was increased to the next size. This tabulation
and pipe selection is shown in Table 6.
For the roof drains, the actual contributing areas were not used. Walmart requires that the
roof drain pipes be sized to accommodate a 5" inches/hour storm and provides flow rates
for these roof drains. The flows for these roof drains were used to calculate adjusted areas
using the 2.37 inches/hour intensity which creates adjusted areas slightly larger than the
actual area.
Table 6: Sub -basin Conveyance Data
Basin
Area(Ac)
CumulaiffWwPipe
Basin
Area(Ac)
Size
(in)
A-1
0.14
0.14
12
A-2
0.05
0.19
12
A-3
0.32
0.51
12
A-4
2.35*
2.86
18
A-5
0.39
3.25
18
A-6
0.42
3.68
24
A-7
0.42
4.59
24
A-8
1.29
5.88
24
A-9
1.04
3.60
24
A-10
0.51
1.56
18
A-11
0.82
1.05
12
A-12
0.22
0.22
12
A-13
2.56*
2.56
18
A-14
0.49*
0.49
12
FlWin
Area
(Ac)
Cumulative
Basin
Area(Ac)
Pipe
Size
(i n)
B-1
2.08
2.08
18
B-2
3.01
3.01
18
B-3
1.67
1.94
18
B-4
0.27
0.27
12
B-5
1.42
5.56
24
B-6
0.09*
0.09
12
B-7
0.09*
0.18
12
B-8
1.19*
1.19
18
B-9
1.95*
1.95
18
B-10
0.27
4.13
24
B-11
0.18
2.68
18
B-12
0.21
0.21
12
B-13
0.32
0.55
12
*Does not equal actual basin area. Roof drains are designed per Walmart standard to
convey a 5 inches/hour intensity storm. These areas have been adjusted by keeping the
flow of the roof drains constant but adjusting the area based on the 25 -year 24-hour 10 -
min Tc intensity of 2.37 inches/hour.
Frontage Conveyance (Stoddard Road):
The conveyance system for Basin C along Stoddard Road is designed per the current
ACHD Policy Manual - Section 8000 Drainage and Stormwater Management. Stoddard
Road is classified as a collector, so the depth of ponding requirements are no curb
overtopping and minimum of one 10 ft lane dry. The inlet spacing is 1,000 feet or based
on spread calculation. Both the spread and 1,000 feet criteria are met.
The 100 -year 24-hour peak flow in the proposed gutter is 2.14 cfs. The longitudinal cross
slope of Stoddard rode is 0.012 ft/ft. The pavement cross slope is 0.015 ft/ft. Atthe
PACLAND job #30001053 Page 10
Drainage Report Meridian, ID
proposed inlet, the maximum spread is 10'. Using the ACHD Stormwater calculator for
spread, these values were entered to calculate the maximum gutter flow of 2.72 cfs, which
is higher than the calculated peak flow of 2.14 cfs, so the gutter can accommodate the
increased runoff. This calculation is included in Appendix B.
The spread was verified at the inlet using the following equation:
T = [(Qn) / (K� S.1.67 SL .5)0.375
Ku = 0.56 in English units
n = Manning's coefficient
Q = Flow rate (ft3/s)
T = Width of flow (spread) (ft)
Sx = Cross slope (ft/ft)
SL = Longitudinal slope (ft/ft)
Using this equation, with an "n" value of 0.012 for troweled concrete, the spread was
calculated as 10'. This is the maximum for this location. The spread will be slightly less in
the actual condition because the inlet is near a driveway. The driveway will cause the
water to spread uninhibited in both directions, making the spread less obtrusive in the
roadway.
PACLAND Job #30001053 Page 11
Drainage Report Meridian, ID
Appendix A
Appendix A Figures
Figure 1: Vicinity Map
Figure 2: Grading and Drainage Plan
Figure 3: Frontage Improvement Plan
Figure 4: Basin Map
Drainage Report Meridian, ID
Figure 1 —Vicinity Map
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Drainage Report Meridian, ID
Figure 3 - Frontage Improvement Plan
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Drainage Report Meridian, ID
Figure 4 — Basin Map
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Drainage Report Meridian, ID
Appendix B
Water Quality and Quantity Design Calculations
Drainage Report
Appended on: Monday, January 30, 2012 8:12:13 AM
LPOOLCOMPUTE [A-001] SUMMARY using Puls, 24 hr Storm Event
Start of live storage:0 ft
Meridian, ID
Event
Match Q PCfs)Q MaxDepthVol (cf)
(ac
Time (hrEmpty
year
20.4937
0.8333
4.4641
32784.4679
0.7526
5.0575
Summary Report of all Detention Pond Data
Project Precips
Event Precip (in)
other 0.50
2 yr 24 h—rF 1.20
100 year F 2.70
BASLIST2
[Basin A] Using [TYPE2.RAC] As [100 year] [24.0]
[Basin A] Using [TYPE2.RAC] As [100 year] [24.0]
LSTEND
Peak Peak T Peak Vol (ac- Area
BasinlD Event (cfs)� (hrs) 0 (re) Method/Loss Raintype
Basin AYO� 20.4937 12:03 1.4759 7.80 AC
SCS TYPE2.R
Basin A Y�� 204937 12.03 1.4759 7.80 SCS TYPE2.RAC
BASLIST
[Basin A]
LSTE N D
Record Id: Basin A
Design Method F SCS IRainfall type I TYPE2.RAC
Hyd Intv
10.00 min lPeaking Factor 484.00
Storm Duration
24.00 hrs Abstraction Coeff 0.20
Pervious Area 0.91 ac [DCIA 6.89 ac
Pervious CN
74.00
IDC CN
98.00
Drainage Report Meridian, ID
Pervious TC F 10.00 min IDC TC
1 10.00 min
Pervious CN Calc
Length 100.00 ft Width 120.00 ft
Description SubArea F Sub cn
Landscape 0.91 ac F 74.00
Pervious Composited CN (AMC 2)
74.00
Pervious TC Calc
Type Description Length Slope Coeff
Misc TT
Sheet 0.00 ft 0.0% 10.0
0.00 in 10.00 min
Pervious TC
10.00 min
DCI - CN Calc
Description
FSubArea Sub cn
Impervious surfaces (pavements, roofs, etc)
F6.89 ac 98.00
DC Composited CN (AMC 2)
F98.00
DCI - TC Calc
Type Description Length Slope Coeff
Misc TT
Sheet 0.00 ft 0.0% 10.0
0.00 in 10.00 min
Pervious TC
10.00 min
HYDLIST SUMMARY
[100 year out]
LSTE N D
HydID IPeak Q (cfs) (Peak T (hrs) (Peak Vol (ac -ft) ICont Area (ac)
100 year out Fo.8333 1 o -72F 1.4743 F 7.8
STORLIST
[Basin A Seepage Bed]
LSTE N D
Record Id: Basin A Seepage Bed
Descrip: Prototype Record Increment 10.10 ft
Start EI. 0.00 ft Max EI. 6.75 ft
Void Ratio 61.20 F -F-
Length 100.00 ft Width 120.00 ft
F--F-Consider
Bottom Only
Drainage Report Meridian, ID
VauItType Node
DISCHLIST
[Basin A Discharge]
LSTEN D
Record Id: Basin A Discharge
Infiltration
Descrip: lPrototype Structure Increment 0.10 ft
Start EI. 0.00 ft IMax EI. F6.75 ft
Infiltration rate 3.00 in/hr IWP Multiplier F 1.00
Drainage Report
Appended on: Monday, January 30, 2012 8:12:51 AM
LPOOLCOMPUTE [B-001] SUMMARY using Puls, 24 hr Storm Event
Start of live storage:0 ft
Meridian, ID
Match Peak Max Depth Vol Time to Em
Event (cfs) Q (cfs)Q (ft) p Vol (cfl (volt (hr) p�
100 30.1634 1.8056 4.4639 42617.8966 0.9784 0.0118
year
Summary Report of all Detention Pond Data
Project Precips
Event Precip (in)
other 0.50
2 yr 24 hr F 1.20
100 year 2.70
BASLIST2
[Basin B] Using [TYPE2.RAC] As [100 year] [24.0]
[Basin B] Using [TYPE2.RAC] As [100 year] [24.0]
LSTEND
Peak Q Peak T �Peak Vol (ac- Area
BasinlD Event (cfs) (hrs) 1 co (ac) Method/Loss Raintype
Basin B 10� 30.1634 1-F2.1782 10.93 SCS TYPE2.RAC
Basin B 100 30.1634 12.03 2.1782 10.93 SCS TYPE2.RAC
year
BASLIST
[Basin B]
LSTE N D
Record Id: Basin B
Design Method F SCS Rainfall type
I TYPE2.RAC
Hyd Intv 10.00 min lPeaking Factor
484.00
Storm Duration 24.00 hrs lAbstraction Coeff
0.20
Pervious Area 0.52 ac DCIA
10.40 ac
Pervious CN
F 74.00
IDC CN
98.00
Drainage Report Meridian, ID
Pervious TC F 10.00 min IDC TC
1 10.00 min
Pervious CN Calc
Length 100.00 ft Width 156.00 ft
Description SubArea F Sub cn
Landscape 0.52 ac 74.00
Pervious Composited CN (AMC 2)
74.00
Pervious TC Calc
Type I Description Length Slope Coeff
Misc TT
Sheet 0.00 ft 0.0% 10.0
0.00 in F 10.00 min
Pervious TC
10.00 m i n
DCI - CN Calc
Description
F SubArea Sub cn
Impervious surfaces (pavements, roofs, etc)
Fl0.41 ac F98.00
DC Composited CN (AMC 2)
F98.00
DCI - TC Calc
Type I Description F Length FSIope FCoeff
F Misc F TT
Sheet 0.00 ft 0.0%F10.0
0.00 in 10.00 min
Pervious TC
10.00 min
HYDLIST SUMMARY
[100 year out]
LSTE N D
HydlD Peak Q (cfs) Peak T (hrs) Peak Vol (ac -ft) Cont Area (ac)
100 year out 1.8056 11.11 2.178 F 10.93
STORLIST
[Basin B Seepage Bed]
LSTE N D
Record Id: Basin B Seepage Bed
Descrip:Prototype Record Increment 0.10 ft
Start EI. 0.00 ft Max EI. 6.75 ft
Void Ratio 61.20
Length 100.00 ft Width 156.00 ft
E -F
-Consider
Bottom Only
Drainage Report Meridian, ID
Vault Type Node
DISCHLIST
[Basin B Discharge]
LSTEND
Record Id: Basin B Discharge
Infiltration
Descrip: lPrototype Structure Increment 0.10 ft
Start EI. 0.00 ft
IMax EI. 6.75 ft
Infiltration rate 5.00 in/hr
JWP Multiplier
F 1.00
5
MC -4500 CHAMBER
NOMINAL 314 .2 INCH [19 mm - 51 mml
CLEAN, CRUSHED, ANGULAR STONE
AASHTO M268 CLASS 2
NON -WOVEN GEOTEXTILE ALL
AROUND ANGULAR STONE T
,_atnn Fmnr-,
THE INSTALLED CHAMBER SYSTEM SHALL PROVIDE THE
LOAD FACTORS SPECIFIED IN THE AASFITO LRFO BRIDGE
DESIGN SPECIFICATIONS SECTION 12.12. FOR EARTH AND
LIVE LOADS, WITH CONSIDERATION FOR IMPACT AND
MULTIPLE VEHICLE PRESENCES.
GRADED SOIUAGGREGATE MIXTURES, <35%
IN 12" [305 mm] LIFTS TO 95% PROCTOR
DENSITY.
PAVEMENT DESIGN (PER [1.96 m]
ENGINEER'S DRAWINGS)
_iIt'ii-C `_poTa�l�y°p�blooyn\ 12"
'0'��_il Uo �'` jIi"liio rcll•(=IIS [305 mm[
e� fo o\ -A 60"[1524 mm]
nj
- " [22 457 mm] N
18"_
ASTMmm]
ASTM C33 Filter SaM
9" [229 mm] MIN.7[21'1'1!mj —12" [305 mm] MIN.
SEEPAGE BED A AND B
NTS
Drainage Report
Appended on: Monday, January 30, 2012 8:14:52 AM
Meridian, ID
LPOOLCOMPUTE [C-0011 SUMMARY using Puls, 24 hr Storm Event
Start of live storage:0 ft
Event I Match Q Peak Q Max Depth Vol (et) V0' Time to Empty
(cfs) (cfs) (ft) F(Vol
(hr)
X00 1,6118 0.1041 2.6149 2187.6217 0:0502 0:0118
Summary Report of all Detention Pond Data
Event jPrecip (in)
other F o.50
2 yr 24 hr f 1.20
100 year F 2.70
BASLIST2
[Basin Cl Using [TYPE2.RAC] As [100 year] [24.0]
[Basin Q Using [TYPE2.RAC] As [100 year] [24.0]
LSTEN D
Peak Peak T Peak Vol (ac- Area
BasinlD Event (cfs)Q (hrs) cf) (ac) Method/Loss Raintype
Basin C '00 1.6118 12.03 0.1147 0.74 SCS TYPE2.RAC
Basin C 100
year
BASLIST
[Basin C]
LSTE N D
Record Id: Basin C
1.6118 12.03 0.1147 0.74 SCS TYPE2.RAC
Design Method SCS Rainfall type
I TYPE2.RAC
Hyd Intv 10.00 min I Peaking Factor
484.00
Storm Duration F 24.00 hrs lAbstraction Coeff
0.20
Pervious Area 0.26 ac DCIA
0.48 ac
Pervious CN 74.00 IDC CN
98.00
Drainage Report
Meridian, ID
Pervious TC 10.00 min
IDC TC 10.00 min
Pervious CN Calc
Description SubArea F Sub cn
Pervious 0.26 ac 74.00
Pervious Composited CN (AMC 2)
74.00
-Consider
Bottom Only
Pervious TC Calc
Type I Description FLength Fslope Coeff F Misc 7 TT
Sheet 0.00 ft 0.0°!° 10.0 0.00 in 10.00 min
Pervious TC 710.00 min
DCI - CN Calc
Description SubArea Sub cn
Impervious surfaces (pavements, roofs, etc) FO.48 ac F98.00
DC Composited CN (AMC 2) F98.00
DCI - TC Calc
Type Description Length Slope Fcoeff F Misc 7 TT
Sheet 0.00 ft 0.0% 10.0 0.00 in 10.00 min
Pervious TC
10.00 min
HYDLIST SUMMARY
[100 year out]
LSTEN D
Hydl D Peak Q (cfs) Peak T (hrs) Peak Vol (ac -ft) Cont Area (ac)
100 year out 0.1041 11.46 0.1147 0.74
STORLIST
[Basin C Seepage Bed]
LSTE N D
Record Id: Basin C Seepage Bed
Descrip: Prototype Record Increment 0.10 ft
Start EI. 0.00 ft Max EI. 5.50 ft
Void Ratio 61.97
F��
Length 27.00 ft Width 50.00 ft
F -F
-Consider
Bottom Only
Drainage Report Meridian, ID
Type Node
DISCHLIST
[Basin C Discharge]
LSTEN D
Record Id: Basin C Discharge
Infiltration
Descrip: Prototype Structure Increment 0.10 ft
Start EI. 1 0.00 ft IMax EI. F5.50 ft
Infiltration rate F 3.33 in/hr IWP Multiplier 1.00
E
[152
MC -3500 CHAMBER
NOMINAL 3/4 - 2INCH [19 mm - 51
CLEAN, CRUSHED, ANGULAR ST
AASHTO M288 CLASS 2
NON -WOVEN GEOTEXTILE ALL
AROUND ANGULAR STONE -
,.. C-3500 ENDCAP
THE INSTALLED CHAMBER SYSTEM SHALL PROVIDE THE
LOAD FACTORS SPECIFIED IN THE AASH HD LRFD BRIDGE
DESIGN SPECIFICATIONS SECTION 12.12 FOR EARTH AND
LIVE LOADS, WITH CONSIDERATION. FOR IMPACT AND
MULTIPLE VEHICLE PRESENCES.
0
6"[152 mm]
GRANULAR WELL GRADED SOIUAGGREGATE MIXTURES,
<35% FINES. COMPACT IN 6" 1152 mm] LIFTS TO 95% PROCTOR
DENSITY.
SEEPAGE BED C
NTS
6.5'[1.98 m]
12"
0 0\ _A 45" [1143 mm]
`9" [229 mm].
18"[457 mm]
ASTM C33 Filter Sand
77 --� [-- 12" [365 mm]
[1956 mm]