HomeMy WebLinkAboutCC - Storm Drainage Calcs :,j LE
DRAINAGE CALCULATIONS
FOR
BRUNDAGE ESTATES
SUBDIVISION NO. 1
ADA COUNTY, IDAHO
October 23, 2024
ENGINEERING SOLUTIONS, LLP
1029 N. Rosario Street, Suite 100
Meridian, Idaho 83642
(208) 938 -0980
�Sg\OKAL FN
v\CENgF C�2�
s� I0
,nrF OF \0
M.
Job Number: 240903
Brundage Estates Subdivision No. 1
Drainage Calculations Report
Brundage Estates Subdivision No. 1 is the first phase of a multi-phase residential
development. The project is generally located in Section 25, T.3N., R.1W., B.M.,
Meridian, Ada County, Idaho. It is located south on the east side of Linder Road
north of the Calkins Lateral and is comprised of 29 residential lots and 5 common
lots on approximately 11.6 acres. The storm drainage from this project will be
intercepted by drop inlets, will flow through sand and grease traps and then into
seepage beds located within common lots or ACHD right-of-way.
Assumptions used for this drainage report are as follows:
1. Rational Equation used to estimate storm runoff(Q = CIA)
2. SCS: TR-55 Method used to determine Time of Concentration (T,)
3. Coefficient of Runoff used is C = 0.50 this is from ACHD Section 8011.2.1
Coefficients of Runoff. Residential Single Family 0.35-0.50. I used
maximum.
4. ACHD Policy allows one half of the entire lot area to be included in the
runoff calculations unless a specific lot grading plan is developed.
The rational method was used to determine the peak discharge. This method uses
a "C" value (0.50 in this case), Time of Concentration (Tc) calculated by SCS TR-
55 methods and rainfall Intensity Duration Frequency (IDF) curves for the Boise
Front from the ACHD Storm Water Design Manual. The rainfall intensity is
determined from the IDF curve where "I" is selected at the calculated Tc and the
100-year return.
I used the latest ACHD spreadsheet Version 10.5, November 2018.
Brundage Estates Subdivision No. 1 is divided into eight runoff collection zones.
The contributing areas are depicted on the attached drainage map. The assumption
is made that the front half is the only contributing portion of the lot. This is based
on the assumption that the rear portion of the lot is self-contained and/or is
delayed long after the peak discharge has passed.
The peak discharge is used to determine the capacity of the pipes and drop inlet. A
minimum value of 10 minutes is used to select the "I" in the peak discharge
calculations. Per ACHD policy, the volume calculations are determined using Tc
of 60 minutes, therefore; I=0.96". I have used the ACHD worksheets Version 10.5
dated November 2018 to determine the peak discharge, and volumes of the
storms.
Proposed Drainage
The proposed drainage system improvements consist of drop inlets, a storm pipe
network, sand and grease traps and seepage beds.
Seepage Bed No. 1.1
Areas 1 and 2 will be picked up in drop inlets and piped to a 1500-gallon sand and
grease trap. From the sand and grease trap an 18" pipe goes 5' into the seepage
bed, then an 18" top only perforated pipe extends through the seepage bed. The
bottom of the bed is in free draining soils and has 3' separation from groundwater.
Seepage Bed No. 1.2
Areas 3 and 4 will be picked up in drop inlets and piped to two 1000-gallon sand
and grease traps. From the sand and grease traps an 18" pipe goes 5' into the
seepage bed, then an 18" top only perforated pipe extends through the seepage
bed. The bottom of the bed is in free draining soils and has 3' separation from
groundwater.
Seepage Bed No. 1.3
Areas 5 and 6 will be picked up in drop inlets and piped to a 1000-gallon sand and
grease trap. From the sand and grease trap an 18" pipe goes 5' into the seepage
bed, then an 18" top only perforated pipe extends through the seepage bed. The
bottom of the bed is in free draining soils and has 3' separation from groundwater.
Areas A and B along Linder Road will flow overland into the bioretention swales
between the shoulder and the 10' pathway/sidewalk.
Seepage Beds
All seepage bed systems are sized for the 100-year storm using the ACHD
spreadsheets. The seepage beds use clean drain rock wrapped in filter fabric to
facilitate drainage, an 18" pipe perforated on the top only and 1.5' of sand
underneath the clean drain rock. The seepage beds also contain a monitoring well
inside the bed and one outside of the bed. The seepage beds were sized using the
percolation rate of the soils at the bottom of the bed. The beds were designed to
have 3' of separation from high groundwater based on the groundwater monitoring
report that was provided.
Bioretention Swales
The bottom of the bioretention swales has a bioretention soil mixture (BSM)per ACHD
standards. An infiltration rate of 1.0 in/hr. to 1.25 in/hr. were used in the calculations.
The bioretention swales are sized for the 100-year runoff volume using the ACHD
Calculation Spreadsheet Version 10.0 (May 2018). The swale along the north (Area A)
will flow to the existing borrow ditch along Linder Road until the remainder of Linder
Road is constructed at which time the bioretention swale will be along the entire road.
� o 0
rr i
3 �
S353o mo
WON
LU
Nu
000 c 6
s Z
F55p HE
NNN
Li
N N N Y
O Yi w.
9!9 0
GOO O O 0 0 0 O O
a m
09R 899 928 8 8 8 5
o m �e
e
Nvio�a
8'Ti N IA 16 . c7Z�� „x
zm
xPM I
gg
po { I U w g
C.3Op
1\'
1
� I
h
1.
/ 1
/• air i - � / ��,
W
///
AVM3a(133MDM S
--TT
!� r
Yo.. O O
rn '
'9a a3UM1S t s ��r�.....��W a3,n--tee 'r�.�._p'(Ia H3(alZl S'-•—ttty-1lt�— _ _ — _._.
N O 0 $ �i O OM N 0 00- � N L O
M
O O O �"� O V' (n M M N CO M V 0
II II II N CO LO It(O O Cl)M (D (`M
7
U
O
(f y
O V V to O O(O V V (O
O 00 I— O_O O 0 m 0 O (O
N U V V 0 'o I'- M N � M V M
m N co M C' I— N N 'ItN
U
N
(>0
O O O
L LO
O O O d
I I 11 11 d
W C) C) C) N U (O Co 0 �m O 000'IT co ^ mrL ui rn co > «�0 r N M O 0 0
N O) O)
J E E E V
o
N cn cn
llJ Q Q Q
Q N co
Z W N
*CO
c9 H V)co 0 0 O O co N N co N
Q f0 alO) w LO W� M t` (O LO CO 0 (M u? V
N O N
Oil l n $
N> > >
00 LO N O N N 00 R (`MN
V0(O Co. (`')O N O O N N O
O— N — (M 1 N O
I1-N 0 O co co 0 0 0 0 co
w M(O 0 ((0 I� N V M I� O p M rn
U O O O O O — 0 0 O O O O X
V
N
M
N
O
�I
O
N N N N N N UI
M
O
0
O
V
N
T T T
(0 (0 co V'«) V V V V VLO V (n (n (n
U- U- U- I N N N O O O O O O OD OJ M
—
0 m 0
_C C_ C_
U) U) U)
O O O
Lq U? U?
O O O
II II II
U 0 0 N N N cc O co M M 0 0 0
N N C)O O cc O coo O O O
E E E
Zn Ncn cn
n N
Q Q QQQ
Q b N O O O 00 O O O O O O O
O N O V 7 00 M M M 00 M O O O
J O O «7 F r__ M M M 00 O LO'IT O O O
LL
M M M N N N
101 •�
Q I I n $
C L0 0 a
W H O O O O O O 0 0 O LO O O
N O N u7 I1- N m M � N O
Q N M N M (O M O N
O
Z p
C Z
O C rn
co N
0 > d
0 0 -o— -a
7 V N Z O a) (0
(n N
N O Q Z v)e-N M V (n(O C, m
d o a a
r Z N m N C J
In n (nn Q
W O LU
d (1)
R LL
C c Q
L
m m
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.
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 Brundage Estates Subdivision No.1-Area 1
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)
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) Acres 1.20
Acres 1.20
6 Determine the Weighted Runoff Coefficient(C) 0.50
C=[(C1xA1)+(C2xA2)+(CnxAn))/A Weighted Avg1 0.50
7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate
min 10 Min. Estimated Runoff Coefficients for Various Surface
Type of Surface Runoff Coefficients"I
Business
Downtown areas 0.70-0.95
Hydraulic Urban neighborhoods 0.50-0.70
Radius Flow Residential
Intercept A/Wet Velocity V Flow Time Single Family 0.35-M50
ID Pipe Size(in) Slope(ft/ft) Coeff. Length Manning n Perm (fps) (min) Mufti-family 0.60-0.75Residential(rural) 0.25-0.40
Segment 1:Pipe Flow Apartment Dwelling Areas 0.70
a Industrial and Commercial
Light areas 0.80
Segment 2:Gutter Shallow Concentrated Flow Heavy areas 0.
90
Se
g Parks,Cemeteries 0.10-0.25
b 0.006 0.619 437 1.5 4.8 Playgrounds 0.20-0.35
Railroad yard areas 0.20-0.40
Segment 3:Overland Sheet Flow By TR-55,<300-ft
c 0.020 30 0.240 3.4 8.9
Computed Tc= 13.7
User-Entered Tc= 13.7
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in r
y Calculate the Post-Development peak discharge(QPeak) QpeA 1.55 cfs
10 Calculate total runoff vol(V)(for sizing primary storage) V 2,074 ft
V=Ci(Tc=60)Ax3600
11 Calculate Volume of Runoff Reduction Vrr
Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in
Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vr, 1,296 ft'
12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs
13 Volume Summary Unimproved areas 0.10-0.30
Surface Storage:Basin Streets
Basin Forebay V 207 W Asphalt 0.95
Concrete 0.95
Primary Treatment/Storage Basin V 1,866 ft' Brick 0.95
Subsurface Storage Roofs 0.95
Volume Without Sediment Factor(See BMP 20 Tab) V 2,074 ft Gravel 0.75
Fields:Sandy 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
K:\Data From PC\2024\240903-Brundage Estates No 1-Lee\Calculations\ACHD_SD_CALCS_Area 1.xlsm 10/23/2024,8:51 AM
Version 10.5,November 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.
calculat ost-d' erit'
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 Brundage Estates Subdivision No.1-Area 2
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)
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) Acres 2.00
Acres 2.00
6 Determine the Weighted Runoff Coefficient(C) 0.50
C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.50
7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate
min 10 Min. Estimated Runoff Coefficients for Various Surface
Type of Surface Runoff Coefficients"t
Business
Downtown areas 0.70-0.95
Hydraulic Urban neighborhoods 0.50-0.70
Radius Flow Residential
Intercept A/Wet Velocity V Flow Time Single Family 0.35-M50
ID Pipe Size(in) Slope(ft/ft) Coeff. Length Manning n Perm (fps) (min) Multi-family 0.60-0.75Residential(rural) 0.25-0.40
Segment 1:Pipe Flow Apartment Dwelling Areas 0.70
a Industrial and Commercial
Light areas 0.80
Heavy areas 0.90
Segment 2:Gutter Shallow Concentrated Flow Parks,Cemeteries 0.10-0.25
b 0.006 0.619 436 1.5 4.8 Playgrounds 0.20-0.35
Railroad yard areas 0.20-0,40
Segment 3:Overland Sheet Flow By TR-55,<300-ft
c 0.020 29 0.240 3.4 8.7
Computed Tc= 13.5
User-Entered Tc= 13.5
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in r
y Calculate the Post-Development peak discharge(QPeak) Qp.A 2.58 cfs
10 Calculate total runoff vol(V)(for sizing primary storage) V 3,456 ft
V=Ci(Tc=60)Ax3600
11 Calculate Volume of Runoff Reduction Vrr
Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in
Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 2,160 ft'
12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs
13 Volume Summary Unimproved areas 0.10-0.30
Surface Storage:Basin streets
Basin Forebay V 346 ft Asphalt 0.95
Concrete 0.95
Primary Treatment/Storage Basin V 3,110 ft' Brick 0.95
Subsurface Storage Roofs 0.95
Volume Without Sediment Factor(See BMP 20 Tab) V 3,456 ft' Gravel 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
K:\Data From PC\2024\240903-Brundage Estates No 1-Lee\Calculations\ACHD_SD_CALCS_Area 2.xlsm 10/23/2024,8:51 AM
Version 10.5,November 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.
t
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 Brundage Estates Subdivision No.1-Areas 1 and 2
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)
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) Acres 1.20 2.00
Acres 3.20
6 Determine the Weighted Runoff Coefficient(C) 0.50 0.50
C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.50
7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate
min 10 Min. Estimated Runoff Coefficients for Various Surface
Type of Surface Runoff Coefficients"I
Business
Downtown areas 0.70-0.95
Hydraulic Urban neighborhoods 0.50-0.70
Radius FlowLFlowTime
Residential
Intercept A/Wet Velocity V Single Family 0.35-0.50
Multi-family 0.60-0.75
ID Pipe Size(in) Slope(ft/ft) Coeff. Length Manning n Perm (fps) Residential(rural) 0.25-0.40
Segment 1:Pipe Flow Apartment Dwelling Areas 0.70
a industrial and Commercial
Light areas 0.80
Parks,areas 0.
Segment 2:Gutter Shallow Concentrated Flow
Parks,Cemeteries 0.1010-0.25
b 0.006 0.619 437 1.5 4.8 Playgrounds 0.20-0.35
Railroad yard areas 0.20-0.40
Segment 3:Overland Sheet Flow By TR-55,<300-ft
c 0.020 30 0.240 3.4 8.9
Computed Tc= 13.7
User-Entered Tc= 13.7
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in r
9 Calculate the Post-Development peak discharge(QPeak) Qpeak 4.13 cfs
10 Calculate total runoff vol(V)(for sizing primary storage) V 5,530 ft
V=Ci(Tc=60)Ax3600
11 Calculate Volume of Runoff Reduction Vrr
Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in
Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 3,456 ft'
12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs
13 Volume Summary Unimproved areas 0AG-0.30
Surface Storage:Basin Streets
Basin Forebay V 553 ft Asphalt 0.95
Concrete 0.95
Primary Treatment/Storage Basin V 4,977 ft' Brick 0.95
Subsurface Storage Roofs 0.95
Volume Without Sediment Factor(See BMP 20 Tab) V 5,530 ft, Gravel 0.75
Fields:Sandy 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
K:\Data From PC\2024\240903-Brundage Estates No 1-Lee\Calculations\ACHD_SD_CALCS_Areas 1 and 2.xlsm 10/23/2024,8:52 AM
Version 10.5,November 2018
ACHD Calculation Sheet for Sand/Grease Traps
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.
Steps for Sand/Grease Trap Velocity Calculation
User input in yellow cells.
1 Project Name Brundage Estates Subdivision No. 1-Areas 1 and 2
2 Enter number of Sand/Grease Traps(25 max) 1
Number of Peak Flow Baffle Throat Velocity Is the
Vault Size Spacing width Area(ft2) 0.5 fps Velocity
S/G Traps Q-cfs
inch inch max. ok?
1500 G 1 4.13 20 60 8.33 0.50
Reference for Throat widths(inch)
ADS
Boise Lar-ken WQU,
Vault BMP 16
1000 G 48.0 50.5 n/a
1500 G 60.0 61.5 n/a
WQU1000 n/a n/a 60
WQU1500 n/a n/a 60
K:\Data From PC\2024\240903-Brundage Estates No 1- Lee\Calculations\ACHD_SD_CALCS_Areas 1 and 2.xlsm 10/23/2024,8:52 AM
Version 10.0, May 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 Brundage Estates Subdivision No.1-Areas 1 and 2
2 Enter number of Seepage Beds(25 max) 1
3 Design Storm 100
4 Weighted Runoff Coefficient C 0.50 Link to: Qv
QV TR55
5 Area A(Acres) 3.20 acres
6 Approved discharge rate(if applicable) 0.00 cfs
7 Is Seepage Bed in Common Lot? No V 6,912 ft3 25%Sediment
8 Set Total Design Width of All Drain Rock W 13.5 ft
9 Set Total Design Depth of All Drain Rock D 7.5 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 1.00 in/hr
12 Size of WQ Perf Pipe(Perf 180°) Dia pipe 18 in
13 Size of Overflow Perf Pipe(Perfs 3600),REQD if Q100>3.3 cfs in
14 Calculate Total Storage per Foot Spf 41.8 ft3/ft
15 Calculate Design Length L 165 ft
Override Value Required for Chambers
16 Variable Infiltration Window L SWL 165 ft
17 Variable Infiltration Window W SWW 13.5 ft
18 Time to Drain 33.4 hours
90%volume in 48-hours minimum
19 Length of WQ&Overflow Perf Pipes 165 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 ft'/Unit
7 Total Number of Units Required 0 ea
8 Area of Infiltration Aperc ft2
9 Volume Infiltration Vperc 0 ft3/hr
10 Time to Drain hours
90%volume in 48-hours minimum
K:\Data From PC\2024\240903-Brundage Estates No 1-Lee\Calculations\ACHD_SD_CALCS_Areas 1 and 2.xlsm 10/23/2024,8:52 AM
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.
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 Brundage Estates Subdivision No.1-Area 3
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(2S max)
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) Acres 2.50
Acres 2.50
6 Determine the Weighted Runoff Coefficient(C) 0.50
C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.50
7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate
min 10 Min. Estimated Runoff Coefficients for Various Surface
Type of Surface Runoff Coefficients"I
Business
Downtown areas 0.70-0.95
Hydraulic Urban neighborhoods 0.50-0.70
Radius Flow Residential
Intercept A/Wet Velocity V Flow Time Single Family 0.35-0.50
ID Pipe Size(in) Slope(ft/ft) Coeff. Length Manning n Perm (fps) (min) Multi-family 0.60-0.75Residential(rural) 0.25-0.40
Segment 1:Pipe Flow Apartment Dwelling Areas 0.70
a Industrial and Commercial
Light areas 0.80
Heavy areas 0.90
Segment 2:Gutter Shallow Concentrated Flow
Parks,Cemeteries 0.1010-0.25
b 0.005 0.619 1,196 1.5 13.4 Playgrounds 0.20-0.35
Railroad yard areas 0.20-0.40
Segment 3:Overland Sheet Flow By TR-55,<300-ft
c 0.020 70 0.240 4.0 17.4
Computed Tc= 30.8
User-Entered Tc= 30.8
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc 1 2.51 in r
y Calculate the Post-Development peak discharge(QPeak) Qpeak 1.89 cfs
10 Calculate total runoff vol(V)(for sizing primary storage) V 4,320 ft
V=Ci(Tc=60)Ax3600
11 Calculate Volume of Runoff Reduction Vrr
Enter Percentile Storm I(9Sth percentile=0.60 in) 95th 0.60 in
Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 2,700 ft'
12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs
13 Volurne Summary Unimproved areas 0.10-0.30
Surface Storage:Basin Streets
Basin Forebay V 432 ft Asphalt 0.95
Concrete 0.95
Primary Treatment/Storage Basin V 3,888 ft' Brick 0.95
Subsurface Storage Roofs 0.95
Volume Without Sediment Factor(See BMP 20 Tab) V 4,320 W Gravel 0.75
Fields:Sandy 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
K:\Data From PC\2024\240903-Brundage Estates No 1-Lee\Calculations\ACHD_SD_CALCS_Area 3.xlsm 10/23/2024,8:53 AM
Version 10.5,November 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.
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 Brundage Estates Subdivision No.1-Area 4
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)
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) Acres 3.70
Acres 3.70
6 Determine the Weighted Runoff Coefficient(C) 0.50
C=[(C1xA1)+(C2xA2)+(CnxAn)j/A Weighted Avg1 0.50
7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 Usercaicuiate
min 10 Min. Estimated Runoff Coefficients for Various Surface
Type of Surface Runoff Coefficients
Business
Downtown areas 0.70-0.95
Hydraulic Urban neighborhoods 0.50-0.70
Radius Flow Residential
Intercept A/Wet Velocity V Flow Time Single Family 0.35-0.50
ID Pipe Size(in) Slope(ft/ft) Coeff. Length Manning n Perm (fps) (min) Multi-family 0.60-0.75Residential(rural) 0.25-0.40
Segment 1:Pipe Flow Apartment Dwelling Areas 0.70
a Industrial and Commercial
Light areas 0.80
Segment 2:Gutter Shallow Concentrated Flow Heavy areas 0.
90 Parks,Cemeteries 0.1010-0.25
b 0.005 0.619 1,196 1.5 13.4 Playgrounds 0.20-0.35
Railroad yard areas 0.20-0.40
Segment 3:Overland Sheet Flow By TR-55,<300-ft
c 0.020 70 0.240 4.0 17.4
Computed Tc= 30.8
User-Entered Tc= 30.8
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.51 in r
y Calculate the Post-Development peak discharge(QPeak) Qpeak 2.79 cfs
10 Calculate total runoff vol(V)(for sizing primary storage) V 6,394 ft
V=Ci(Tc=60)Ax3600
11 Calculate Volume of Runoff Reduction Vrr
Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in
Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 3,996 ft'
12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs
13 Volume Summary Unimproved areas 0.10-0.30
Surface Storage:Basin Streets
Basin Forebay V 639 ft Asphalt 0.95
Concrete 0.95
Primary Treatment/Storage Basin V 5,754 ft' Brick 0.95
Subsurface Storage Roofs 0.95
Volume Without Sediment Factor(See BMP 20 Tab) V 6,394 ft' Gravel 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
K:\Data From PC\2024\240903-Brundage Estates No 1-Lee\Calculations\ACHD_SD_CALCS_Area 4.xlsm 10/23/2024,8:53 AM
Version 10.5,November 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 P g the
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 Brundage Estates Subdivision No.1-Area 3 and 4
2 Is area drainage basin map provided? YES
(map must be included with stormwoter calculations)
3 Enter Design Storm(100-Year or 25-Year With 100-Year Flood Route) 100
4 Enter number of storage facilities(25 max)
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) Acres 2.50 3.70
Acres 6.20
6 Determine the Weighted Runoff Coefficient(C) 0.50 0.50
C=[(C1xA1)+(C2xA2)+(CnxAn)J/A Weighted Avg1 0.50
7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 user Calculate
min 10 Min. Estimated Runoff Coefficients for Various Surface
Type of Surface Runoff Coefficients"I
Business
Downtown areas 0.70-0.95
Hydraulic Urban neighborhoods 0.50-0.70
Radius Flow Residential
Intercept A/Wet Velocity V Flow Time Single Family 0.35-0.50
ID Pipe Size(in) Slope(ft/ft) Coeff. Length Manning n Perm (fps) (min) Multi-family 0.60-0.75Residential(rural) 0.25-0.40
Segment 1:Pipe Flow Apartment Dwelling Areas 0.70
a Industrial and Commercial
Light areas 0.80
Heavy areas 0.90
Segment 2:Gutter Shallow Concentrated Flow
Parks,Cemeteries 0.10-0.25
b 0.005 0.619 1,196 1.5 13.4 Playgrounds 0.20-0.35
Railroad yard areas 0.20-0.40
Segment 3:Overland Sheet Flow By TR-55,<300-ft
c 0.020 70 0.240 4.0 17.4
Computed Tc= 30.8
User-Entered Tc= 30.8
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.51 in r
y Calculate the Post-Development peak discharge(QPeak) Qpeak 4.68 cfs
10 Calculate total runoff vol(V)(for sizing primary storage) V 10,714 ft
V=Ci(Tc=60)Ax3600
it Calculate Volume of Runoff Reduction Vrr
Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in
Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) V„ 6,696 ft,
12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfS
13 Volume Summary Unimproved areas 0.10-0.30
Surface Storage:Basin Streets
Basin Forebay V 1,071 ft Asphalt 0.95
Concrete 0.95
Primary Treatment/Storage Basin V 9,642 ft' Brick 0.95
Subsurface Storage Roofs 0.95
Volume Without Sediment Factor(See BMP 20 Tab) V 10,714 ft' Gravel 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:N% 0.13 0.18 0.23 0.
Adapted from ASCE
K:\Data From PC\2024\240903-Brundage Estates No 1-Lee\Calculations\ACHD_SD_CALCS_Area 3 and 4.xlsm 10/23/2024,8:54 AM
Version 10.5,November 2018
ACHD Calculation Sheet for Sand/Grease Traps
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.
Steps for Sand/Grease Trap Velocity Calculation
User input in yellow cells.
1 Project Name Brundage Estates Subdivision No. 1-Area 3 and 4
2 Enter number of Sand/Grease Traps(25 max) 1
Number of Peak Flow Baffle Throat Velocity Is the
Vault Size Spacing width Area(ft2) 0.5 fps Velocity
S/G Traps Q-cfs inch inch max. ok?
1000 G 2 4.68 20 48 13.33 0.35
Reference for Throat widths(inch)
Boise ADS
Vault Lar-ken WQU,
BMP 16
1000 G 48.0 50.5 n/a
1500 G 60.0 61.5 n/a
WQU 1000 n/a n/a 60
WQU 1500 n/a n/a 60
K:\Data From PC\2024\240903-Brundage Estates No 1- Lee\Calculations\ACHD_SD_CALCS_Area 3 and 4.xlsm 10/23/2024,8:54 AM
Version 10.0, May 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 Brundage Estates Subdivision No.1-Area 3 and 4
2 Enter number of Seepage Beds(25 max) 1
3 Design Storm 100
4 Weighted Runoff Coefficient C 0.50 Link to: LOV
QV TR55
5 Area A(Acres) 6.20 acres
6 Approved discharge rate(if applicable) 0.00 cfs
7 Is Seepage Bed in Common Lot? Yes V 10,714 ft3 0%Sediment
8 Set Total Design Width of All Drain Rock W 15.0 ft
9 Set Total Design Depth of All Drain Rock D 9.2 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 1.00 in/hr
12 Size of WQ Perf Pipe(Pert 180°) 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 56.6 ft3/ft
15 Calculate Design Length L 189 190 ft
Override Value Required for Chambers
16 Variable Infiltration Window L SWL 190 ft
17 Variable Infiltration Window W SWW 15.0 ft
18 Time to Drain 40.6 hours
90%volume in 48-hours minimum ._
19 Length of WQ&Overflow Perf Pipes 190 ft
20 Perf Pipe Checks.Qperf>=Qpeak;
where Qperf=CdxAxd(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 ft'/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 ft2
9 Volume Infiltration Vperc 0 ft3/hr
10 Time to Drain hours
90%volume in 48-hours minimum
K:\Data From PC\2024\240903-Brundage Estates No 1-Lee\Calculations\ACHD_SD_CALCS_Area 3 and 4.xlsm 10/23/2024,8:54 AM
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.
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 Brundage Estates Subdivision No.1-Area 5
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)
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) Acres 1.90
Acres 1.90
6 Determine the Weighted Runoff Coefficient(C) 0.50
C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.50
7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate
min 10 Min. Estimated Runoff Coefficients for Various Surface
Type of Surface Runoff Coefficients"I
Business
Downtown areas 0.70-0.95
Hydraulic Urban neighborhoods 0.50-0.70
Radius Flow Residential
Intercept A/Wet Velocity V Flow Time single Family 0.35-0.50
ID Pipe Size(in) Slope(ft/ft) Coeff. Length Manning n Perm (fps) (min) Mufti-family 0.60-0.75Residential(rural) 0.25-0.40
Segment 1:Pipe Flow Apartment Dwelling Areas 0.70
a Industrial and Commercial
Light areas 0.80
90
Segment 2:Gutter Shallow Concentrated Flow Heavy areas 0.
g Parks,Cemeteries 0.10-0.25
b 0.009 0.619 921 1.9 7.9 Playgrounds 0.20-0.35
Railroad yard areas 0.20-0.40
Segment 3:Overland Sheet Flow By TR-55,<300-ft
c 0.020 70 0.240 4.0 17.4
Computed Tc= 25.3
User-Entered Tc= 25.3
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.58 in r
y Calculate the Post-Development peak discharge(QPeak) Qpeak 1.50 cfs
10 Calculate total runoff vol(V)(for sizing primary storage) V 3,283 ft
V=Ci(Tc=60)Ax3600
11 Calculate Volume of Runoff Reduction Vrr
Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in
Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 2,052 ftJ
12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs
13 Volume Summary Unimproved areas 0.10-0.30
Surface Storage:Basin Streets
Basin Forebay V 328 ft Asphalt 0.95
Concrete 0.95
Primary Treatment/Storage Basin V 2,955 ft' Brick 0.95
Subsurface Storage Roofs 0.95
Volume Without Sediment Factor(See BMP 20 Tab) V 3,283 ft' Gravel 0.75
Fields:Sandy 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
K:\Data From PC\2024\240903-Brundage Estates No 1-Lee\Calculations\ACHD_SD_CALCS_Area 5.xlsm 10/23/2024,8:55 AM
Version 10.5,November 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.
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 Brundage Estates Subdivision No.1-Area 6
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)
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) Acres 1.80
Acres 1.80
6 Determine the Weighted Runoff Coefficient(C) 0.50
C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.50
7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate
min 10 Min. Estimated Runoff Coefficients for Various Surfau
Type of Surface Runoff Coefficients
Business
Downtown areas 0.70-0.95
Hydraulic Urban neighborhoods 0.50-0.70
Radius Flow Residential
Intercept A/Wet Velocity V Flow Time Single Family 0.35-0.50
ID Pipe Size(in) Slope(ft/ft) Coeff. Length Manning n Perm (fps) (min) Multi-family 0.60-0.75Residential(rural) 0.25-0.40
Segment 1:Pipe Flow Apartment Dwelling Areas 0.70
a Industrial and Commercial
Light areas 0.80
Heavy areas 0.90
Segment 2:Gutter Shallow Concentrated Flow
Parks,Cemeteries 0.1010
-0.25
b 0.010 0.619 897 2.0 +_I.6 Playgrounds 0.20-0.35
Railroad yard areas 0.20-0.40
Segment 3:Overland Sheet Flow By TR-55,<300-ft
c 0.020 69 0.240 4.0 17.2
Computed Tc= 24.8
User-Entered Tc= 24.8
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.81 in r
y Calculate the Post-Development peak discharge(QPeak) Qpeak 1.63 cfs
10 Calculate total runoff vol(V)(for sizing primary storage) V 3,110 ft
V=Ci(Tc=60)Ax3600
11 Calculate Volume of Runoff Reduction Vrr
Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in
Enter Runoff Reduction Vol(95th Percenti►e=0.60-in x Area x C) Vrr 1,944 ft
12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs
13 Volume Summary Unimproved areas 0.10-0.30
Surface Storage:Basin Streets
Basin Forebay V 311 ft Asphalt 0.95
Concrete 0.95
Primary Treatment/StorageBasin V 2,799 ft' Brick 0.95
Subsurface Storage Roofs 0.95
Volume Without Sediment Factor(See BMP 20 Tab) V 3,110 ft' Gravel 0.75
Fields:Sandy soil Soil Type
Slope A B C D
Flat:O-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
K:\Data From PC\2024\240903-Brundage Estates No 1-Lee\Calculations\ACHD_SD_CALCS_Area 6.xlsm 10/23/2024,8:55 AM
Version 10.5,November 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.
the'Ratlonal' L
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 Brundage Estates Subdivision No.1-Areas 5 and 6
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)
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) Acres 1.90 1.80
Acres 3.70
6 Determine the Weighted Runoff Coefficient(C) 0.50 0.50
C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.50
7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate
min 10 Min. Estimated Runoff Coefficients for Various Surfac,
Type of Surface Runoff Coefficients"I
Business
Downtown areas 0.70-0.95
Hydraulic Urban neighborhoods 0.50-0.70
Radius Flow Residential
Intercept A/Wet Velocity V Flow Time Single Family 0.35-0.50
ID Pipe Size(in) Slope(ft/ft) Coeff. Length Manning n Perm (fps) (min) Multi-family 0.60-0.75Residential rural 0.25-0.40
Segment 1:Pipe Flow Apartment Dwelling Areas 0.70
a Industrial and Commercial
Light areas 0.80
Segment 2:Gutter Shallow Concentrated Flow Heavy areas 0.90
Parks,Cemeteries 0.10-0.25
b 0.009 0.619 921 1.9 7.9 Playgrounds 0.20-0.35
Railroad yard areas 0.20-0.40
Segment 3:Overland Sheet Flow By TR-55,<300-ft
c 0.020 70 0.240 4.0 17.4
Computed Tc= 25.3
User-Entered Tc= 25.3
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.58 in r
y Calculate the Post-Development peak discharge(QPeak) Qpeak 2.92 cfs
10 Calculate total runoff vol(V)(for sizing primary storage) V 6,394 ft
V=Ci(Tc=60)Ax3600
11 Calculate Volume of Runoff Reduction Vrr
Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in
Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 3,996 ft'
12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs
13 Volume Summary Unimproved areas 0.10-0.30
Surface Storage:Basin Streets
Basin Forebay V 639 ft Asphalt 0.95
Concrete 0.95
Primary Treatment/Storage Basin V 5,754 ft' Brick 0.95
Subsurface Storage Roofs 0.95
Volume Without Sediment Factor(See BMP 20 Tab) V 6,394 ft' Gravel 0.75
Fields:Sandy 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
K:\Data From PC\2024\240903-Brundage Estates No 1-Lee\Calculations\ACHD_SD_CALCS_Area 5 and 6.xlsm 10/23/2024,9:00 AM
Version 10.5,November 2018
ACHD Calculation Sheet for Sand/Grease Traps
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.
Steps for Sand/Grease Trap Velocity Calculation
User input in yellow cells.
1 Project Name Brundage Estates Subdivision No.1-Areas 5 and 6
2 Enter number of Sand/Grease Traps(25 max) 1
fNumber of Peak Flow Baffle Throat Velocity Is the
l
ault Size Spacing width Area(ft2) 0.5 fps Velocity
S/G Traps Q-cfs
inch inch max. ok?
00 GG 1 2.92 20 48 6.67 0.44
Reference for Throat widths(inch)
ADS
Boise Lar-ken WQU,
Vault BMP 16
1000 G 48.0 50.5 n/a
1500 G 60.0 61.5 n/a
WQU1000 n/a n/a 60
WQU1500 n/a n/a 60
K:\Data From PC\2024\240903- Brundage Estates No 1-Lee\Calculations\ACHD_SD_CALCS_Area 5 and 6.xlsm 10/23/2024,8:56 AM
Version 10.0, May 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 Brundage Estates Subdivision No.1-Areas 5 and 6
2 Enter number of Seepage Beds(25 max) 1
3 Design Storm 100
4 Weighted Runoff Coefficient C 0.50 Link to: Qv
QV TR55
5 Area A(Acres) 3.70 acres
6 Approved discharge rate(if applicable) 0.00 cfs
7 Is Seepage Bed in Common Lot? Yes V 6,394 ft3 0%Sediment
8 Set Total Design Width of All Drain Rock W 10.0 ft
9 Set Total Design Depth of All Drain Rock D 9.0 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 1.00 in/hr
12 Size of WQ Perf Pipe(Perf 1800) Dia pipe 18 in
13 Size of Overflow Perf Pipe(Perfs 360°),REQD if Q100>3.3 cfs in
14 Calculate Total Storage per Foot Spf 37.0 ft3/ft
15 Calculate Design Length L 173 175 ft
Override Value Required for Chambers
16 Variable Infiltration Window L SWL 175 ft
17 Variable Infiltration Window W SWW 10.0 ft
18 Time to Drain 39.5 hours
90%volume in 48-hours minimum
19 Length of WQ&Overflow Perf Pipes 175 ft
20 Perf Pipe Checks.Qperf>=Qpeak;
where Qperf=CdxAxd(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 ft 3
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 ft2
9 Volume Infiltration Vperc 0 ft3/hr
10 Time to Drain hours
90%volume in 48-hours minimum
K:\Data From PC\2024\240903-Brundage Estates No 1-Lee\Calculations\ACHD_SD_CALCS_Area 5 and 6.xlsm 10/23/2024,8:56 AM
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.
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 Brundage Subdivision No.1-Linder Road Area A-Phase 1 Only
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)
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) Acres 0.25
Acres 0.25
6 Determine the Weighted Runoff Coefficient(C) 0.50
C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.50
7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User calculate
min 10 Min. Estimated Runoff Coefficients for Various Surfac.
Type of Surface Runoff Coefficients"I
Business
Downtown areas 0.70-0.95
Hydraulic Urban neighborhoods 0.50-0.70
Radius Flow Residential
Intercept A/Wet Velocity V Flow Time Single Family 0.35-0.50
ID Pipe Size(in) Slope(ft/ft) Coeff. Length Manning n Perm (fps) (min) Multi-family 0.60-0.75
Residential(rural) 0.25-0.40
Segment 1:Pipe Flow Apartment Dwelling Areas 0.70
a Industrial and Commercial
Light areas 0.80
Segment 2:Gutter Shallow Concentrated Flow Heavy areas 0.90
Parks,Cemeteries 0.10-0.25
b Playgrounds 0.20-0.35
Railroad yard areas 0.20-0.40
Segment 3:Overland Sheet Flow By TR-55,<300-ft
c 0.020 34 0.240 3.5 9.8
Computed Tc= 9.8
User-Entered Tc= 10.0
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in r
y Calculate the Post-Development peak discharge(QPeak) Qpeak 0.32 cfs
10 Calculate total runoff vol(V)(for sizing primary storage) V 432 ft
V=Ci(Tc=60)Ax3600
11 Calculate Volume of Runoff Reduction Vrr
Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in
Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vr, 270 ft,
12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs
13 Volume Summary Unimproved areas 0.10-0.30
Surface Storage:Basin Streets
Basin Forebay V 43 ft Asphalt 0.95
Concrete 0.95
Primary Treatment/Storage Basin V 389 W Brick 0.95
Subsurface Storage Roofs 0.95
Volume Without Sediment Factor(See BMP 20 Tab) V 432 ft' Gravel 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
K:\Data From PC\2024\240903-Brundage Estates No 1-Lee\Calculations\ACHD_SD_CALCS_240429 Linder Road A.xlsm 10/23/2024,9:02 AM
Version 10.5,November 2018
ACHD Calculation Sheet for Sizing Bioswales & Borrow Ditches
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 Project Name Brundage Subdivision No.1-Linder Road Area A-Phase 1 Only
2 Enter number of Bioswales/Borrow Ditches(25 max) 1
3 Design Storm 100
Weighted Runoff Coefficient C 0.50 Link to:LQ,v
4 Area A(Acres) 0.25 acres QV TR55
Approved discharge rate for the given storm(if applicable) 0.00 cfs
5 Design Vol With 0%Sed for Swales V 432 ft3
6 Length of Swale 45 ft
7 Infiltration Window?(Note:infiltration required if Longitudinal Sloped%)
Design Infiltration Rate 1.25 in/hr
8 Infiltration Window Width 2.00 ft
9 Set Swale Bottom Width b 2.00 ft
10 Set Swale Top Width 14.00 ft
11 Set Swale Depth y 1.50 ft
12 Swale Side Slopes H:1 Sxs 4.00
13 Calculate cross-sectional area Axs 12.00 ftz
Axs= z y z+by
14 Total Swale Capacity Without Driveways 534 ft3
15 Does it Have Capacity? OK
16 Time to Drain 46.6 hr
90%volume in 48-hours minimum OK
Check Swale With Driveways
17 Avg.Driveway Fill Slope in Swale (H/V) 0.00 ft/ft
18 Enter Total Number of Driveways 0 ea 0.0 ft3 Deduct driveway slope
19 Enter Total Length of all Driveways 0 ft 0.0 ft3 Deduct driveway length
20 Lost Swale Length From Trees,etc. 0 ft 0.0 ft3 Deduct other
21 Adjusted Length of Infiltration Area 44.5 ft
22 Excess Capacity=Storage-Deductions-Runoff Volume 102.0 ft3
23 Is Capacity Good? YES
24 Time to Drain 103.6 hr
90%volume in 48-hours minimum OK
K:\Data From PC\2024\240903-Brundage Estates No 1-Lee\Calculations\ACHD_SD_CALCS_240429 Linder Road A.xlsm 10/23/2024,9:02 AM
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.
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 Brundage Subdivision No.1-Linder Road Area B
2 Is area drainage basin map provided? YES
(map must be included with stormwater calculations)
3 Enter Design Storm(100-Year or 2S-Year With 100-Year Flood Route) 100
4 Enter number of storage facilities(25 max)
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) Acres 1.10
Acres 1.10
6 Determine the Weighted Runoff Coefficient(C) 0.50
C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.50
7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate
min 10 Min. Estimated Runoff Coefficients for Various Surface
Type of Surface Runoff Coefficients"I
Business
Downtown areas 0.70-0.95
Hydraulic Urban neighborhoods 0.5070.70
Radius Flow Residential
Intercept A/Wet Velocity V Flow Time Single Family 0.35-0-50
ID Pipe Size(in) Slope(ft/ft) Coeff. Length Manning n Perm (fps) (min) Multi-family 0.60-0.75
Residential(rural) 0.25-0.40
Segment 1:Pipe Flow
Apartment Dwelling Areas 0.70
a Industrial and Commercial
Light areas 0.80
Heavy areas 0.90
Segment 2:Gutter Shallow Concentrated Flow Parks,Cemeteries o.lo o.z5
b Playgrounds 0.20-0.35
Railroad yard areas 0.20-0,40
Segment 3:Overland Sheet Flow By TR-55,<300-ft
c 0.020 34 0.240 3.5 9.8
Computed Tc= 9.8
User-Entered Tc= 10.0
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in r
y Calculate the Post-Development peak discharge(QPeak) Qpeak 1.42 cfs
10 Calculate total runoff vol(V)(for sizing primary storage) V 1,901 ft
V=Ci(Tc=60)Ax3600
11 Calculate Volume of Runoff Reduction Vrr
Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in
Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 1,188 ft'
12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs
13 Volume Summary Unimproved areas 0.10-0.30
Surface Storage:Basin Streets
Basin Forebay V 190 ft' Asphalt 0.95
Concrete 0.95
Primary Treatment/StorageBasin V 1,711 ft Brick 0.95
Subsurface Storage Roofs 0.95
Volume Without Sediment Factor(See BMP 20 Tab) V 1,901 ft' Gravel 0.75
Fields:Sandy 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
K:\Data From PC\2024\240903-Brundage Estates No 1-Lee\Calculations\ACHD_SD_CALCS_240429 Linder Road B.xlsm 10/23/2024,8:44 AM
Version 10.5,November 2018
ACHD Calculation Sheet for Sizing Bioswales & Borrow Ditches
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 Project Name Brundage Subdivision No.1-Linder Road Area B
2 Enter number of Bioswales/Borrow Ditches(25 max) 1
3 Design Storm 100
Weighted Runoff Coefficient C 0.50 Link to:LQV
4 Area A(Acres) 1.10 acres Qv TR55 -�
Approved discharge rate for the given storm(if applicable) 0.00 cfs
5 Design Vol With 0%Sed for Swales V 1,901 ft3
6 Length of Swale 430 ft
7 Infiltration Window?(Note:infiltration required if Longitudinal Sloped%)
Design Infiltration Rate 1.00 in/hr
8 Infiltration Window Width 2.00 ft
9 Set Swale Bottom Width b 2.00 ft
10 Set Swale Top Width 10.00 ft
11 Set Swale Depth y 1.00 ft
12 Swale Side Slopes HA Sxs 4.00
13 Calculate cross-sectional area Axs 6.00 ft1
Axs= zy z+by
14 Total Swale Capacity Without Driveways 2,580 ft3
15 Does it Have Capacity? OK
16 Time to Drain 26.5 hr
90%volume in 48-hours minimum OK
Check Swale With Driveways
17 Avg.Driveway Fill Slope in Swale (H/V) 0.00 ft/ft
18 Enter Total Number of Driveways 0 ea 0.0 ft3 Deduct driveway slope
19 Enter Total Length of all Driveways 0 ft 0.0 ft3 Deduct driveway length
20 Lost Swale Length From Trees,etc. 0 ft 0.0 ft3 Deduct other
21 Adjusted Length of Infiltration Area 430.0 ft
22 Excess Capacity=Storage-Deductions-Runoff Volume 679.2 ft3
23 Is Capacity Good? YES
24 Time to Drain 58.9 hr
90%volume in 48-hours minimum OK
K:\Data From PC\2024\240903-Brundage Estates No 1-Lee\Calculations\ACHD_SD_CALCS_240429 Linder Road B.xlsm 10/23/2024,8:44 AM
Version 10.0,May 2018