HomeMy WebLinkAboutCC - Franklin Flex Drainage Report LAKE HAVASU CITY OFFICE
T R I C O
231 SWANSON AVENUE,STE.204
LAKE HAVASU CITY,AZ 86403
ENGINEERING, LLC (928)230-4969
Drainage Design Report
for
FRANKLIN FLEX STORAGE
4211 E Lanark Street in Meridian, ID.
Prepared for
Hatch Design Architecture
200 W 36th Street
Boise, ID 83714
o �
P-21157
I �3 � a
. PER
EXPIRES 12-31-2025
State of Idaho No. 21157
Trico PN# 22-077
June 13, 2024
TABLE OF CONTENTS PAGE NO.
1.0 INTRODUCTION/PURPOSE ............................................................ 3
2.0 LOCATION .................................................................................. 3
3.0 SITE DESCRIPTION AND PROPOSED DEVELOPMENT ........................ 4
4.0 FEMA FLOODPLAIN CLASSIFICATION ............................................ 4
5.0 SURVEY AND MAPPING ................................................................ 4
6.0 OFF-SITE DRAINAGE DESCRIPTION ............................................... 4
7.0 PROPOSED ON-SITE DRAINAGE PLAN DESCRIPTION ........................ 4
8.0 HYDROLOGY ............................................................................... 4
9.0 HYDRAULICS ............................................................................... 5
10.0 STORMWATER DETENTION REQUIREMENTS ................................... 5
11.0 CONCLUSIONS AND RECOMMENDATIONS ...................................... 5
12.0 REFERENCES .............................................................................. 6
APPENDIX A—FEMA FIRMette MAP
APPENDIX B—DRAINAGE EXHIBITS
APPENDIX C—HYDRAULIC CALCULATIONS
-2- Hatch Design—Franklin Flex Storage
Drainage Design Report
June 13,2024
1.0 INTRODUCTION/PURPOSE
The Franklin Flex Storage (Project) is being developed by Hatch Design Architecture and is
located at 4211 E Lanark Street in Meridian, ID (APN 51109438871). The purpose of this report
is to show that the proposed development was designed to meet the code requirements set forth by
Garden City (City) and Ada County (County) and to provide the supporting documentation
required by the County's Development Services Department for the Developer to acquire the
pertinent permit(s) to construct the Project. The project, as currently presented, consists of three
entities being; a Public Roadway Extension, a private flex facility on the north side of the public
roadway extension,and a private development on the south side still under design for its final uses.
2.0 LOCATION
The site is further described as 4.92 acres at the end of S Lanark St and along Franklin Rd a portion
of the lot where Section 09, Township 3 North, Range 1 East of Meridian in Ada County, Idaho.
Refer to the Vicinity Map below.
Vicinity Man
'-well I/
r '
SITE
1
+ 1 -
� '7 E. LANARK ST. "-
wLU
Cr0
E.FRANKLIN RD.
a~
-3- Hatch Design—Franklin Flex Storage
Drainage Design Report
June 13,2024
3.0 SITE DESCRIPTIONAND PROPOSED DEVELOPMENT
The existing site consists of improved vacant land with minor vegetation that drains at
approximately 1%to the south. Additionally, along the north side of the Site there is a stormwater
open channel that will be converted to flow through a culverted pipe for the limits of the property.
The site is accessed via paved public roads from Lanark Street and Franklin St. The Project will
include the other applicable utilities that will include, but not be limited to water, sewer, electric,
etc. These utilities will be carefully designed with respect to each other to eliminate conflicts.
4.0 FEMA FLOODPLAIN CLASSIFICATION
The Site is identified on Flood Insurance Rate Map (FIRM) panel number 16001 CO252G, Ada
County, effective February 19, 2003. The site is located within Zone "X" designation. This is
described as, "0.2% annual chance flood hazard, areas of 1% annual chance flood with average
depth less than one foot or with drainage areas of less than one square mile." Refer to Appendix
A for the FIRMette Map of this area and more detail where the zones described are located on the
Site.
5.0 SURVEYAND MAPPING
A Topographic Map was provided by Accurate Surveying & Mapping, dated March 19, 2021.
Additionally, a boundary and topographic base file was provided and was incorporated into the
plans as the basis of design for the Project.
6.0 OFF-SITE DRAINAGE DESCRIPTION
The off-site flow conditions have minimal to no impact for this project.
7.0 PROPOSED ON-SITE DRAINAGE PLAN DESCRIPTION
The drainage for this Project was designed in accordance with Ada County requirements,including
no requested deviations from it. In general, for the public roadway extension, flows will be split at
the street crown line and drained to a catch basin on each side of the roadway. Storm drain will be
installed from the north to the south side where a public underground seepage bed is located. Per
Ada County, the seepage bed has been sized 25% larger to accommodate public flows. For the
onsite portion of the project roof drainage and hardscape surfaces will be designed to drain toward
their respective drive aisles,where flow will be carried in a ribbon gutter to the east into a privately
dedicated underground seepage bed. Flows and retained volumes are further described below.
Driveways involved with the Project were designed with the intent to keep privately generated
flows within the private portions of the Project, while maintaining existing flows within the right-
of-way.
8.0 HYDROLOGY
The hydrology for this Project was analyzed using the 25-year and 100-year storm events as
required by Ada County based on the Boise Area IDF Curves provided within ACHD Drainage
calculation spreadsheet. The method of hydrology calculations will be using the Rational Method
with a minimum 10-minute time of concentration, resulting in 25-year and 100-year rainfall
intensities of 1.85 and 2.58 in/hr, respectively. Runoff coefficients of 0.50 and 0.95 for the pre-
and post-developed conditions were used in the calculations for the Project.
-4- Hatch Design—Franklin Flex Storage
Drainage Design Report
June 13,2024
9.0 HYDRA ULICS
Drainage flows will be determined by their respective contributing tributary areas. These areas
were broken down into sub-areas that will be used for determining peak flows to analyze capacity
of each drainage structure. The summary of peak discharges are presented below, as well as
depicted within the Hydrology Map in Appendix B of this report:
Summary of Peak Discharges
Rational Method-Q=C x i X A
Where: Cpre=Runoff Coefficient= 0.50
Cp.,t=Runoff Coefficient= 0.95
i=Rainfall Intensity(2-year)= 0.69
i=Rainfall Intensity(10-year)= 1.45
i=Rainfall Intensity(25-year)= 1.85
i=Rainfall Intensity(100-year)= 2.58
A=Area in acres
DRAINAGE PRE-DEVELOPED POST-DEVELOPED
DESIGN POINT AREA PEAK FLOW cfs PEAK FLOW cfs
AC 2-YR 10-YR 25-YR 100-YR 2-YR I 10-YR 25-YR 100-YR
1 1.71 0.59 1.24 1.58 2.58 1.12 2.36 3.01 4.19
2A 0.145 0.05 0.11 0.13 0.19 0.10 0.20 0.25 0.36
213 0.145 0.05 0.11 0.13 0.19 0.10 0.20 0.25 0.36
10.0 STORMWA TER DETENTION REQUIREMENTS
The stormwater detention for this Project was designed in accordance with ACHD using
underground Seepage Beds that have been designed to detain the post-developed 100-year storm
event. In general,the seepage beds consist of a sand/grease separator,through an 18-inch pipe into
an 8-ft deep, filled with 2-inch washed drain rock with intention to percolate through a sand filter
in the bottom.
Supporting hydraulic calculations are found in Appendix C of this report. During and after large
rain events,the inlets and detention basins will need to be inspected and maintained to remain clear
of any debris.
11.0 CONCLUSIONS AND RECOMMENDATIONS
The proposed Project will adhere to Ada County drainage criteria to retain the 100-year storm
event flow. There are no anticipated offsite flows that will impact the proposed structures. Any
unanticipated offsite flows will remain within the right-of-way and conveyed along the existing
road beyond the Project. The project, as currently presented, consists of three entities being; a
Public Roadway Extension, a private flex facility on the north side of the public roadway
extension, and a private development on the south side still under design for its final uses.
-5- Hatch Design-Franklin Flex Storage
Drainage Design Report
June 13,2024
12.0 REFERENCES
Ada County Highway District Drainage Design Management Manual, dated August 2017
APPENDICES
APPENDIX A—FEMA FIRM MAP
APPENDIX B—DRAINAGE EXHIBITS
APPENDIX C—HYDRAULIC CALCULATIONS
-6- Hatch Design—Franklin Flex Storage
Drainage Design Report
June 13,2024
Appendix A
FEMA FIRMette Map
-7- Hatch Design—Franklin Flex Storage
Drainage Design Report
June 13,2024
National Flood Hazard Layer FIRMette FEMA Legend
116o20'50"W 439636"N SEE FIS REPORT FOR DETAILED LEGEND AND INDEX MAP FOR FIRM PANEL LAYOUT
Without Base Flood Elevation(BFE)
Zone A,V,A99
SPECIAL FLOOD With BFE or Depth Zone AE,AO,AH,VE,AR
City of Meridian HAZARD AREAS Regulatory Floodway
160180
0.2%Annual Chance Flood Hazard,Areas
of 1%annual chance flood with average
depth less than one foot or with drainage
areas of less than one square mile zone x
_ Future Conditions 1%Annual
Chance Flood Hazard zonex
Area with Reduced Flood Risk due to
OTHER AREAS OF Levee.See Notes.Zone
FLOOD HAZARD Area with Flood Risk due to Leveezone D
NO SCREEN Area of Minimal Flood Hazard zonex
Q Effective LOMRs
OTHER AREAS Area of Undetermined Flood Hazard zone
TaN R1 E S09 ---
GENERAL - Channel,Culvert,or Storm Sewer
STRUCTURES IIIIIII Levee,Dike,or Floodwall
Ada fount} cl`—� Cross Sections with 1%Annual Chance
160001 17n5 Water Surface Elevation
AkEA OF MINIMAL FLOOD HAZARD City of$oi - - Coastal Transect
Qz0f]2 fs'.F •J ^^^^-5n— Base Flood Elevation Line(BFE)
1 60 Limit of Study
Jurisdiction Boundary
—--- Coastal Transect Baseline
�ry r ,# u OTHER _ Profile Baseline
!J + + FEATURES Hydrographic Feature
F r
Digital Data Available N
No Digital Data Available
MAP PANELS Unmapped
The pin displayed on the map is an approximate
point selected by the user and does not represent
an authoritative property location.
This map complies with FEMA's standards for the use of
digital flood maps if it is not void as described below.
The basemap shown complies with FEMA's basemap
I accuracy standards
The flood hazard information is derived directly from the
73N R1 E S16 authoritative NFHL web services provided by FEMA.This map
-- ---___ -- was exported on 5/17/2024 at 3:16 PM and does not
reflect changes or amendments subsequent to this date and
time.The NFHL and effective information may change or
become superseded by new data over time.
r
This map image is void if the one or more of the following map
elements do not appear:basemap imagery,flood zone labels,
legend,scale bar,map creation date,community identifiers,
116020'12"W 43°36'10"N FIRM panel number,and FIRM effective date.Map images for
Feet 1:6 000 unmapped and unmodernized areas cannot be used for
0 250 500 1,000 1,500 2,000 regulatory purposes.
Basemap Imagery Source:USGS National Map 2023
Appendix B
Drainage Exhibit
-8- Hatch Design—Franklin Flex Storage
Drainage Design Report
June 13,2024
DA 2A DA 2B
AREA=6,316 SF AREA=6,316 SF
C=0.95 C=0.95
Qioo=0.36 CFS Qioo=0.36 CFS ..
i
VAN
i
SYSTEM#2
7 �
II
VOL.REQ D-1,190 CF
VOL.PROV D-1,190 CF bi
DA 1- YSTEM#1
AREA-74 488 SF VOL.VOL.REQ D=5614CF
C=0.95 VOL.PROV'D=5,614 CF IF II
Q,00=4.19 CFS
FLEX BUILDING
(FINISHED FLOOR VARIES)
Lo
Qz
� F-1 I
W
H I
� li I
a
w
VAN N
--- - - - - GRAPHIC SCALE
MEN
i
30 0 15 30
TR I C O E. LANARK ST. CMG DRAINAGE AREA MAP (IN FEET)
FLEX STORAGE 1 inch = 30 feet
ENGINEERING, LLC
4211 E. LANARK ST. DATE: MAY 17,2024 FD77N BY: SDP DRAWING NO.:
231 SWANSON AVENUE,STE.204 DWG SCALE: 1"=30' CHECKED BY: EJP A
LAKE HAVASU CITY,466 AZ 86403 MERIDIAN, ID 83642 PROJECT NO: 22-077 1L��
(928)208-4661
APPROVED BY: SDP SHEET 1 OF 1
Appendix C
Hydraulic Calculations
-9- Hatch Design—Franklin Flex Storage
Drainage Design Report
June 13,2024
ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology.These
calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted.
for Peak Discharge Rate using th r post-developm
Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab)
User input in yellow cells.
1 Project Name Franklin Storage-Onsite Imp's
2 Is area drainage basin map provided? YES
(map must be included with stormwater calculations)
3 Enter Design Storm(100-Year or 25-Year With 100-Year Flood Route) 100
4 Enter number of storage facilities(25 max) 1
Click to Show More Subbasins ❑
Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin
1 Subbasin 2 3 4 5 Subbasin 6 7 8 9 10
5 Area of Drainage Subbasin(SF or Acres) SF 74,488
Acres 1.71
6 Determine the Weighted Runoff Coefficient(C) 0.95
C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg 0.95
7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate
min
10 Min. I Estimated Runoff Coefficients for Various Surface
Type of Surface Runoff Coefficients"I
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc 2.58 in/hr Business
Downtown areas 0.70-0.95
9 Calculate the Post-Development peak discharge(ClPeak) peak 4.19 cfs Urban neighborhoods 0.50-0.70
Residential
10 Calculate total runoff vol(V)(for sizing primarystora e) V 5,614 f Single Family 0.35-0.50
Multi-family 0.60-0.75
V=Ci(Tc=60)Ax3600 Residential(rural) 0.25-0.40
11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70
Industrial and Commercial
Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Light areas 0.80
Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr, 3,509 W Heavy areas 0.90
12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfS Parks,cemeteries 0.
Playgrounds 0.20-0.0-0.35
5
Railroad yard areas 0.20-0.40
13 Volume Summary Unimproved areas 0.10-0.30
Surface Storage:Basin Streets
Asphalt 095
Basin Foreba V 561 ft' .
Y Concrete 0.95
Primary Treatment/StorageBasin V 5,053 ft' Brick 0.95
Subsurface Storage Roofs 0.95
Gravel
Volume Without Sediment Factor(See BMP 20 Tab) V 5,614 ft'
Fields:Sandy soil Soil Soil Type
Slope A B C D
Flat:0-2% 0.04 0.07 0.11 0.
Average:2-6% 0.09 0.12 0.15 0.
Steep:>6% 0.13 0.18 0.23 0.
Adapted from ASCE
F:\Trico Engineering LLC\Projects\2022\22-077_Hatch Franklin Self Storage(idaho)\Calculations\ACHD_SD_CALCS_112018_Basin l.xlsm 5/17/2024,2:33 PM
Version 10.5,November 2018
ACHD Calculation Sheet for Sizing Seepage Bed With Optional Chambers
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the
Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in
facilities that meet or exceed these calculations in order to be accepted.
Note this spreadsheet pulls information from the"Peak QV"tab
Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab)
User input in yellow cells.
1 Project Name Franklin Storage-Onsite Imp's
2 Enter number of Seepage Beds(25 max) 1
3 Design Storm 100
4 Weighted Runoff Coefficient C 0.95 Link to: Lqv
QV TR55
5 Area A(Acres) 1.71 acres
6 Approved discharge rate(if applicable) 0.71 cis
7 Is Seepage Bed in Common Lot? Yes V 5,614 ft3 0%Sediment
8 Set Total Design Width of All Drain Rock W 9.0 ft
9 Set Total Design Depth of All Drain Rock D 8.0 ft
Rock Only,Do Not Include Filter Sand Depth or Cover
10 Void Ratio of Drain Rock Voids 0.4
0.4 for 1.5"-2"drain rock and 3/4"Chips
11 Design Infiltration Rate(8 in/hr max) Perc 1.25 in/hr
12 Size of WQ Perf Pipe(Pert 1800) Dia pipe 18 in
13 Size of Overflow Perf Pipe(Perfs 3600),READ if Q100>3.3 cfs in
14 Calculate Total Storage per Foot Spf 29.9 Oft
15 Calculate Design Length L 0 114 ft
Override Value Required for Chambers
16 Variable Infiltration Window L SWL 114 ft
17 Variable Infiltration Window W SWW 9.0 ft
18 Time to Drain 47.3 hours
90%volume in 48-hours minimum
19 Length of WQ&Overflow Perf Pipes 114 ft
20 Perf Pipe Checks.Qperf>=Qpeak;
where Qperf=CdxAxV(2xgxH)
Optional Storage Chambers
Note:This assumes chambers are organized in a rectangular layout.
1-StormTech,
1 Type of Chambers SC740
2 Volume to Store V 0 ft3
3 Installed Chamber Width Cw 4.25 ft
Installed Chamber Depth Cd 2.50 ft
Installed Chamber Height Ch 7.12 ft
4 Chamber Void Factor
5 Chamber Storage Volume,Without Rock,Per Manuf 45.90 ft3/Unit
6 Chamber Storage Volume,With Rock,Per Manuf 74.90 ft3/Unit
7 Total Number of Units Required 0 ea
8 Area of Infiltration Aperc ftz
9 Volume Infiltration Vperc 0 ft3/hr
10 Time to Drain hours
90%volume in 48-hours minimum
F:\Trico Engineering LLC\Projects\2022\22-077_Hatch Franklin Self Storage(idaho)\Calculations\ACHD_SD_CALCS_112018_Basin 1.xlsm 6/13/2024,3:27 PM
Version 10.0,May 2018
ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology.These
calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted.
for Peak Discharge Rate using th r post-developm
Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab)
User input in yellow cells.
1 Project Name Franklin Storage-Lanark Street Imp's
2 Is area drainage basin map provided? YES
(map must be included with stormwater calculations)
3 Enter Design Storm(100-Year or 25-Year With 100-Year Flood Route) 100
4 Enter number of storage facilities(25 max) 1
Click to Show More Subbasins ❑
Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin
1 Subbasin 2 3 4 5 Subbasin 6 7 8 9 10
5 Area of Drainage Subbasin(SF or Acres) SF 6,316 6,316
Acres 0.29
6 Determine the Weighted Runoff Coefficient(C) 0.95 0.95
C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg 0.95
7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate
min
10 Min. I Estimated Runoff Coefficients for Various Surface
Type of Surface Runoff Coefficients"I
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in/hr Business
Downtown areas 0.70-0.95
9 Calculate the Post-Development peak discharge(QPeak) QPeak 0.71 cfs Urban neighborhoods 0.50-0.70
Residential
10 Calculate total runoff vol V for sizing e V ft Single Family 0.35-0.50
( )( g primary ry storage)) 952 Multi-family 0.60-0.75
V=Ci(Tc=60)Ax3600 Residential(rural) 0.25-0.40
11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70
Industrial and Commercial
Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Light areas 0.80
Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 595 W Heavy areas 0.90
12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Parks,cemeteries 0.
Playgrounds 0.20-0.0-0.35
5
Railroad yard areas 0.20-0.40
13 Volume Summary Unimproved areas 0.10-0.30
Surface Storage:Basin Streets
Asphalt 095
Basin Foreba V 95 ft' .
Y Concrete 0.95
Primary Treatment/StorageBasin V 857 ft' Brick 0.95
Subsurface Storage Roofs 0.95
Gravel
Volume Without Sediment Factor(See BMP 20 Tab) V 952 ft'
Fields:Sandy soil Soil Soil Type
Slope A B C D
Flat:0-2% 0.04 0.07 0.11 0.
Average:2-6% 0.09 0.12 0.15 0.
Steep:>6% 0.13 0.18 0.23 0.
Adapted from ASCE
F:\Trico Engineering LLC\Projects\2022\22-077_Hatch Franklin Self Storage(idaho)\Calculations\ACHD_SD_CALCS_112018.xlsm 5/17/2024,1:47 PM
Version 10.5,November 2018
ACHD Calculation Sheet for Sizing Seepage Bed With Optional Chambers
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's
calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities
that meet or exceed these calculations in order to be accepted.
Note this spreadsheet pulls information from the"Peak QV"tab
Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab)
User input in yellow cells.
1 Project Name Franklin Storage-Lanark Street Imp's
2 Enter number of Seepage Beds(25 max) 1
3 Design Storm 100
4 Weighted Runoff Coefficient C 0.95 Unkto: Qv
QV TR55
5 Area A(Acres) 0.29 acres
6 Approved discharge rate(if applicable) 0.00 cfs
7 Is Seepage Bed in Common Lot? No V 1,190 1,190 ft3 25%Sediment
8 Set Total Design Width of All Drain Rock W 9.0 ft
9 Set Total Design Depth of All Drain Rock D 8.0 ft
Rock Only,Do Not Include Filter Sand Depth or Cover
10 Void Ratio of Drain Rock Voids 0.4
0.4 for 1.5"-2"drain rock and 3/4"Chips
11 Design Infiltration Rate(8 in/hr max) Perc 1.25 in/hr
12 Size of WQ Perf Pipe(Perf 180°) Dia pipe 18 in
13 Size of Overflow Perf Pipe(Perfs 3601),READ if Q100>3.3 cfs in
14 Calculate Total Storage per Foot Spf 29.9 Oft
15 Calculate Design Length L 40 40 ft
Override Value Required for Chambers
16 Variable Infiltration Window L SWL 40 ft
17 Variable Infiltration Window W SWW 9.0 ft
18 Time to Drain 28.6 hours
90%volume in 48-hours minimum
19 Length of WQ&Overflow Perf Pipes 40 ft
20 Perf Pipe Checks.Qperf>=Qpeak;
_where Qperf=CdxAxV(2xgxH)
Optional Storage Chamber;—
Note:This assumes chambers are organized in a rectangular layout.
1 Type of Chambers
2 Volume to Store V 0 ft3
3 Installed Chamber Width Cw 0.00 ft
Installed Chamber Depth Cd 0.00 ft
Installed Chamber Height Ch 0.00 ft
4 Chamber Void Factor
5 Chamber Storage Volume,Without Rock,Per Manuf 0.00 ft3/Unit
6 Chamber Storage Volume,With Rock,Per Manuf 0.00 ft3/Unit
7 Total Number of Units Required ea
8 Area of Infiltration Aperc ftz
9 Volume Infiltration Vperc 0 ft3/hr
10 Time to Drain hours
90%volume in 48-hours minimum
F:\Trico Engineering LLC\Projects\2022\22-077_Hatch Franklin Self Storage(idaho)\Calculations\ACHD_SD_CALCS_112018.xlsm 6/13/2024,3:22 PM
Version 10.0,May 2018
ACHD Calculation Sheet for Street Storage
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's
calculation methodology.These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that
meet or exceed these calculations in order to be accepted.
User input in yellow cells.
1 Franklin Storage-Lanark Street Imp's
CURB INFORMATION
2 Street Functional Classification Local
3 Curb Type Hwae=6-in Vertical
4 Height of Curb at Gutter Flow Line Hcvae= 5.75 in
5 Gutter Depression a- 0.75 in
6 Gutter Width W= 1.50 ft
7 Gutter Cross Slope,Sw=a/W+S, SW= 0.062 ft/ft
STREET INFORMATION
8 Street Width Back/Back BB 41.0 it
9 Pavement Cross Slope Sx= 0.020 ft/ft
10 Planter Width Wpu"tn 5.0 ft
11 Planter Cross Slope PLTR,, 0.020 ft/ft
12 Sidewalk Width Wsw 7.0 ft
13 Longitudinal Slope Upstream-Enter 0 for sump condition So= 0.0200 ft/ft
14 Manning's Roughness for Street Section u,nve,- 0.013
15 Max.Allowable Water Spread From Face of Curb,One Side Tv.= 20.0 it
Total Dry Pavement 0 ft
Local c2"at Crown,no curb overtopping
Collector one 10-ft dry lane,no curb overtopping
Arterial two 12-ft dry lanes,no curb overtopping
GRATE/FRAME SPECS
16 Inlet on grade or sag? Sag
17 Select Inlet Grate Type ACHD Std Grate,SD-61
18 Width Grate Wz= 1.42 ft
19 Length Grate Ls= 2.27 it
20 Grate weir length P(grate perimeter excluding curbside) Pg 5.10 ft
21 Clearopening area ofgrate Ag 2.02 tt-
INLET IN SAG -
18 Splash-over Velocity Vo 5.00 ft/s
19 Frontal flow efficiency torgrate,Fir=1-K�(V-Vo) RP 0.85
20 Side flow efficiency R,= 0.03
21 Interception capacity,Qi=QIRt Ee+R,(1-E.)) Q 5.39 CFS
22 Bypass flow,Qb=Qr Q Qb= 21.77 CFS
23 Inlet Efficiency C1R Ee 0.20
24 INLET IN SAG INTERCEPTION CAPACITY Q= 27.26 CFS MAX STORAGE AREA=OSF
CALCULATE STREET STORAGE 2.00
Enter Station and Elevation at Grade Breaks Station CL Elev
25 Sump Boundary for Match Elev>=Down Ste.GB?"NO"Default NO NN/A pN/A
GBl...........................................
GB2...........................................
GB3........................................... LU
G84........................................... JLu
GB5...........................................
GB6...........................................
GB7...........................................
GB8........................................... 0.00
GB9........................................... + 1+Do
GB10........................................... PROFILE
GB11...........................................
GB12...........................................
GB13...........................................
GB14...........................................
GB15...........................................
GB16...........................................
GB17...........................................
GB18...........................................
GB19...........................................
GB20...........................................
GB21...........................................
GB22...........................................
GB23...........................................
GB24...........................................
GB25...........................................
26 Sump Boundary for Match Elev—Down Ste.GB?"NO"Default NO NN/A pN/A
27 TOTAL STREET STORAGE
F:\Trico Engineering LLC\Projects\2022\22-077_Hatch Franklin Self Storage(Ida ho)\Calculations\A.CH D_SD_CALCS_312018.xism 5/17/2024,1:53 PM
Version 10.0,May 2018