HomeMy WebLinkAbout009 - Appendix H - Design Report
JOB NO. B23-048
MONTANA | WASHINGTON | IDAHO | NORTH DAKOTA | PENNSYLVANIA
MAY 2024
406.586.0277
tdhengineering.com
234 East Babcock Street
Suite 3
Bozeman, MT 59715
CLIENT ENGINEER
Intrinsik Architecture, Inc.
106 East Babcock Avenue, Suite 1A
Bozeman, MT 59715
TD&H Engineering
234 East Babcock Street, Suite 3
Bozeman, MT 59715
Engineer: Cody Croskey, PE
ROUSE BLOCK B CONDIMINIUM BUILDING
BOZEMAN, MONTANA
BASIS OF DESIGN REPORT
Image courtesy of GGLO
5/21/2024
B23-048 Rouse Block B Condiminium Building Page 1 of 4
ROUSE BLOCK B CONDOS
ENGINEERING DESIGN REPORT
MAY 2024
Purpose and Introduction
The purpose of this report is to explain how water, sanitary sewer, and storm drainage
improvements will be designed to meet the City of Bozeman requirements and Montana
Public Works Standard Specifications (MPWSS) to provide service to a residential
project in downtown Bozeman, Montana.
The project is located on the north side of East Babcock Street between South Church
Ave. and South Wallace Ave. The property is comprised of lots 17 through 25 and East
26.5 in Block B of the Rouse First Addition to the City of Bozeman totaling 0.90 acres in
size. The property is zoned (B-3) Central Business. Lots 17 & 18 are currently developed
with an existing two-story residential structure and separate garage outbuilding, with
parking access from the private drive aisle to the north. Lots 19 through 22 are fully
developed with two existing two-story multi-family residential structures and internal
parking, with parking access from East Babcock Street and the private drive aisle to the
north. Lots 23 & 24 are currently developed with an existing single-story residential
structure, with parking access from East Babcock Street. Lots 25 and East 26.5 are
partially developed with an existing single-story residential structure and separate
garage outbuilding, with parking access from East Babcock Street.
Proposed redevelopment includes the demolition of the existing buildings and new site
improvements with construction of one new multi-story residential building. Site
improvements will include open space, pedestrian sidewalks, plazas, landscaping
features and a below ground parking lot.
Design Report
Water
All properties have existing live water services, each connected to the existing buildings
on site. These services are proposed to be abandoned at their connection points with
the water main in conjunction with demolition activities at the site. The estimated existing
domestic water demands being removed with the existing buildings are summarized in
Table 1 below with supporting assumptions and calculations provided in Appendix A in
accordance with C.O.B. DSSP Section V.A.4 and the 2017 Water Facility Plan.
Table 1:
Estimated Existing Water Demands (Being Removed)
Parcel Average Day Max. Day Peak Hour
Lots 17 & 18 -(368.9) gpd -(0.59) gpm -(0.77) gpm
Lots 19 & 20 -(3689) gpd -(5.89) gpm -(7.69) gpm
Lots 21 & 22 -(3689) gpd -(5.89) gpm -(7.69) gpm
Lots 23 & 24 -(368.9) gpd -(0.59) gpm -(0.77) gpm
Lots 25 & East 26.5 -(368.9) gpd -(0.59) gpm -(0.77) gpm
TOTAL -(8484.7) gpd -(13.55) gpm -(17.69) gpm
B23-048 Rouse Block B Condiminium Building Page 2 of 4
The new residential building will replace the existing structures with 46 new dwelling
units. The new estimated domestic water demands for the project are summarized in
Table 2 below with supporting assumptions and calculations provided in Appendix A in
accordance with C.O.B. DSSP Section V.A.4 and the 2017 Water Facility Plan.
Table 2:
Estimated New Water Demands
Average Day Max. Day Peak Hour
New Building Demand 16,529 gpd 26.4 gpm 34.4 gpm
Irrigation at the site will also be supplied from the building’s public water supply.
A new 4-inch domestic water service and 6-inch fire service line will be extended to the
new building from the 8-inch water main in East Babcock Street. Final service sizing will
be verified by the mechanical engineer in accordance with the Uniform Plumbing Code,
actual fixture unit counts, and fire protection system requirements. The services will be
Class 51 ductile iron and be installed per the City of Bozeman Design Standards and
Modifications to Montana Public Works Standard Specifications (MPWSS).
The fire flow requirement for the new building is 1,500 gpm based on building size and
construction type as determined following International Fire Code Appendix B criteria. A
fire hydrant flow report was provided by the City Engineering Department for the nearest
fire hydrant to confirm the existing water main has adequate capacity to convey the
maximum day plus fire flow demand for the proposed development in accordance with
C.O.B. DSSP Section V.A.4. The hydrant flow data indicates an available fire flow of
12,400 gpm before dropping below a residual pressure of 20 psi. The project fire flow
determination and fire hydrant flow reports are provided in appendix A.
Sewer
The property has existing live sewer services connected to the existing residences.
These services are proposed to be abandoned in conjunction with demolition activities at
the site. The estimated sewer demands being removed from the existing buildings are
summarized in Table 3 below with supporting assumptions and calculations provided in
Appendix B in accordance with C.O.B. DSSP Section V.B and the 2015 Wastewater
Facilities Plan.
Table 3:
Estimated Existing Sewer Demands (Being Removed)
Parcel Average Day (gpd) Peak Hour (gpm)
Lots 17 & 18 -(162.9) gpd -(0.52) gpm
Lots 19 & 20 -(1385.8) gpd -(4.23) gpm
Lots 21 & 22 -(1385.8) gpd -(4.23) gpm
Lots 23 & 24 -(162.9) gpd -(0.52) gpm
Lots 25 & East 26.5 -(162.9) gpd -(0.52) gpm
ALL PARCELS -(3260.3) gpd -(9.86) gpm
The new residential apartment building will replace the existing uses with 46 new
dwelling units. The new estimated domestic sewer demands for the project are
summarized in Table 4 below with supporting assumptions and calculations provided in
B23-048 Rouse Block B Condiminium Building Page 3 of 4
Appendix B in accordance with C.O.B. DSSP Section V.B and the 2015 Wastewater
Facilities Plan.
Table 4:
Estimated New Sewer Demands
Average Day (gpd) Peak Hour (gpm)
New Building Demand 6,289 gpd 18.64 gpm
Lot Infiltration 135 gpd 0.09 gpm
TOTAL 6,289 gpd 18.64 gpm
A new 6-inch sewer service is proposed to extend from the new building to a
replacement 8-inch sewer main in running east to west along the north side of the
property to a manhole in South Wallace Ave. Final service sizing for this project will be
verified by the mechanical engineer in accordance with the Uniform Plumbing Code and
actual fixture unit counts. The new sewer service lines will be SDR-26 PVC and will be
installed per the City of Bozeman Design Standards and Modifications to Montana Public
Works Standard Specifications (MPWSS).
Storm Drainage
Existing Conditions: The existing project site consists of three single-family residential
dwellings, two multifamily dwellings, two outbuildings, concrete and asphalt paved areas,
gravel driveways, and open spaces. The entire site slopes generally to the north with
most of the runoff appearing to be directed to the alley, flowing west, and conveyed via
curb and gutter to existing storm inlets in South Church Ave. A smaller fraction of the
runoff from the site flows south into East Babcock Street and is conveyed via curb and
gutter to existing storm inlets in South Church Avenue.
Stormwater Quantity: The proposed site development includes one new multi-story
building along with new pedestrian sidewalks and plazas. Landscaping consisting of
planting beds and trees will be established around the west and south sides of the site.
All of the stormwater from the building roof area and on-site plazas will be collected and
conveyed via piping to an underground chamber designed to retain & infiltrate the 10-yr,
2-hr design storm. Stormwater runoff from the widened sidewalks along the street
frontage will drain toward East Babcock Street and be conveyed via curb and gutter to
the existing storm conveyance along East Babcock Street and South Church Ave.
Stormwater runoff calculations for the above-mentioned drainage areas are provided in
Appendix C.
Stormwater Quality: As mentioned previously, stormwater runoff from the building roof
areas, on-site plazas will be collected and routed to a sub-surface chamber facility
designed to capture and fully retain/infiltrate the flow from the 10-yr, 2-hr storm event.
The design retention volume has also been confirmed to have enough storage capacity
to capture the first half inch of rainfall from the building roof area and plazas as shown in
the stormwater runoff calculations provided in Appendix C.
B23-048 Rouse Block B Condiminium Building Page 4 of 4
Infiltration: A new monitoring well was drilled in February 2024 to verify anticipated
groundwater depths to confirm the subsurface infiltration strategy and design elevations.
The well log reported static groundwater levels encountered at depths ranging from 17 to
22 feet below the ground surface. It is anticipated that groundwater will be sufficiently
deep even with seasonal fluctuations to allow for a full retention/infiltration strategy to be
successful at this site. Over-excavation below the infiltration facilities or connections to
deep dry wells will likely be required to tie the systems into the deeper native gravels
below. The GWIC monitoring well log, as well as weekly well monitoring data on this site
is provided in Appendix C.
APPENDIX A
Water Demand Calculations
Fire Flow Request Form
Hydrant Flow Data
Rouse Block B Condiminiums
Date: 05.02.2024
New Water Demand Calculation
Domestic Water Demand - New Building:
Residential Use:
Residential Units =46 units
People =97.1 people (2.11 people/unit)
Residential Flow =16,500 GPD (170 gpcd)(Per COB Design Standards)
Commercial Use:
1,655 sf
0.04 acres
Commercial Flow =28.5 GPD 750 gal/acre/day (Per COB 2017 Water
Facility Plan, Table 3.5)
Peak Hour Demand:
Average Day Demand =16,529 GPD (All Uses)
Average Day Demand =11.5 gpm (GPD / 1,440 minutes)
Maximum Day Demand =26.4 gpm (Ave. Day x Peaking Factor = 2.3)
Peak Hour Demand =34.4 gpm (Ave. Day x Peaking Factor = 3)
Fire Flow Requirement - New Building:
IBC Construction Type =IIIA
Fire Flow Calculation Area =172,538 sf
Automatic Fire Sprinkler System =Yes
Fire Sprinkler System Type =NFPA 13R
Required Fire Flow =1,500 gpm (per IFC Appendix B)
(Per COB 2015 Wastewater
Facility Plan)
Rouse Block B Condiminiums
Date: 05.02.2024
Existing Water Demand Calculation
Domestic Water Demand - Existing Buildings:
Residential Use:
Residential Units =23 units
People =49.91 people (2.17 people/unit)
Residential Flow =8,485 GPD (170 gpcd)(Per COB Design Standards)
Commercial Use:
Retail/Office =0 sf
0.000 acres
Commercial Flow =0.0 GPD 750 gal/acre/day (Per COB 2017 Water
Facility Plan, Table 3.5)
Peak Hour Demand:
Average Day Demand =8,484.7 GPD (All Uses)
Average Day Demand =5.89 gpm (GPD / 1,440 minutes)
Maximum Day Demand =13.55 gpm (Ave. Day x Peaking Factor = 2.3)
Peak Hour Demand =17.68 gpm (Ave. Day x Peaking Factor = 3)
(Per COB 2015 Wastewater
Facility Plan)
CITY OF BOZEMAN
Fire Flow Request Form
PHONE (406) 582-3200 FAX (406) 582-3201
Date April 5th 2023
Location Rouse Ave and Main Street
Pressure Zone HGL 5125 (S)
GIS Hydrant ID# 33, 199, 2384
Adjacent Main Size 4-inch DI, 6-inch DI, 8-inch DI
Model Scenario Maximum Day Demand, Steady State, Fire Flow
Reference 2017 Water Facility Plan Update1
Hydrant Curves An Excel Spreadsheet with hydrant curves has been provided for the requested
location
Requested Location via the Bozeman Infrastructure Viewer2
If you have questions or need further information feel free to email.
Data Disclaimer: Water distribution information is calculated using hydraulic modeling software and is subject to
variation. Actual field conditions may vary. This information is provided to the requestor for evaluation purposes only,
without warranty of any kind, including, but not limited to any expressed or implied warranty arising by contract, stature, or
law. In no event regardless of cause, shall the City be liable for any direct, indirect, special, punitive or consequential
damages of any kind whether such damages arise under contract, tort, strict liability or inequity.
HOME OF MONTANA STATE UNIVERSITY
GATEWAY TO YELLOWSTONE PARK
1 https://www.bozeman.net/home/showpublisheddocument/4977/636420174896170000
2 https://gisweb.bozeman.net/Html5Viewer/?viewer=infrastructure
GIS Hydrant #
Available Flow (gpm)Residual Pressure (psi)2384
0 126.25
200 125.96
400 125.6
600 125.19
800 124.72
1,000.00 124.2
1,200.00 123.64
1,400.00 123.02
1,600.00 122.36
1,800.00 121.64
2,000.00 120.89
2,200.00 120.08
2,400.00 119.23
2,600.00 118.34
2,800.00 117.4
3,000.00 116.42
3,200.00 115.4
3,400.00 114.33
3,600.00 113.21
3,800.00 112.05
4,000.00 110.84
4,200.00 109.59
4,400.00 108.3
4,600.00 106.96
4,800.00 105.58
5,000.00 104.16
5,200.00 102.7
5,400.00 101.2
5,600.00 99.65
5,800.00 98.05
6,000.00 96.38
6,200.00 94.66
6,400.00 92.9
6,600.00 91.11
6,800.00 89.26
7,000.00 87.37
7,200.00 85.44
7,400.00 83.47
7,600.00 81.45
7,800.00 79.4
8,000.00 77.3
8,200.00 75.15
8,400.00 72.97
8,600.00 70.74
8,800.00 68.48
9,000.00 66.17
9,200.00 63.82
9,400.00 61.43
9,600.00 58.99
9,800.00 56.52
10,000.00 54.01
10,200.00 51.45
10,400.00 48.86
10,600.00 46.22
10,800.00 43.54
11,000.00 40.83
11,200.00 38.07
11,400.00 35.27
11,600.00 32.44
11,800.00 29.56
12,000.00 26.65
12,200.00 23.69
12,400.00 20.7
12,600.00 17.67
12,800.00 14.6
13,000.00 11.45
13,200.00 8.32
13,400.00 5.12
13,600.00 1.87
Hydrant Curve
0
20
40
60
80
100
120
140
0 2000 4000 6000 8000 10000 12000 14000 16000Residual Pressure (psi)Available Flow (gpm)
Hydrant Curve
2384
Data Disclaimer: Water distribution information is calculated using hydraulic modeling software and is subject to variation. Actual
field conditions may vary. This information is provided to the requestor for evaluation purposes only, without warranty of any
kind, including, but not limited to any expressed or implied warranty arising by contract, stature, or law. In no event regardless of
cause, shall the City be liable for any direct, indirect, special, punitive or consequential damages of any kind whether such
damages arise under contract, tort, strict liability or inequity.
APPENDIX B
Sewer Demand Calculations
Sewer Service Pipe Capacity Calculations
Rouse Block B Condiminiums
Date: 05.02.2024
New Sewer Demand Calculation
Average Day Sewer Demand :
Residential Use:
Residential Units =46 units
Population =97.1 people (2.11 people/unit)
Residential Flow =6,251 GPD (64.4 gpcd)
Commercial Use:
1,655 sf
0.04 acres
Commercial Flow =38.0 GPD 1,000 gal/acre/day per Table 2-12
2015 Wastewater Facility Plan
Infiltration:
Property Size =0.90 acres
Infiltration Flow =135 GPD (150 gpd/acre per COB Design Standards)
Total Development Average Day Demand:
6,424 GPD (residential + commercial + infiltration)
Total Development Peak Sewer Flow:
Average Day Demand =6,289 GPD (residential + commercial)
P =0.0971 (population/1,000)
Peaking Factor =4.25
Peak Sewer Demand =26,709 GPD (avg. day demand)*(peaking factor)
+ Infiltration Flow =135 GPD (not peaked)
Total Peak Flow =26,844 GPD (residential + commercial + infiltration)
Peak Sewer Flow =18.64 GPM (peak flow)/(24 hrs/day)/(60 min/hr)
Values per C.O.B.
2015 Wastewater Facilities Plan
𝑄𝑚𝑎𝑥
𝑄𝑎𝑣𝑔
=18 +𝑠ℎ𝑛𝑠𝑠𝑎𝑛𝑑𝑠𝑛𝑑𝑛𝑑𝑛𝑛𝑙𝑑1/2
4 +𝑠ℎ𝑛𝑠𝑠𝑎𝑛𝑑𝑠𝑛𝑑𝑛𝑑𝑛𝑛𝑙𝑑1/2
Rouse Block B Condiminiums
Date: 05.02.2024
Existing Sewer Demand Calculation
Average Day Sewer Demand - Existing Buildings:
Residential Use:
Residential Units =23 units
Population =48.53 people (2.11 people/unit)
Residential Flow =3,125 GPD (64.4 gpcd)
Commercial Use:
Retail/Office =0 sf
0.000 acres
Commercial Flow =0.0 GPD 1,000 gal/acre/day per Table 2-12
2015 Wastewater Facilities Plan
Infiltration:
Property Size =0.90 acres
Infiltration Flow =135 GPD (150 gpd/acre per COB Design Standards)
Total Existing Average Day Demand:
3,260.3 GPD (residential + commercial + infiltration)
Total Existing Peak Sewer Flow:
Average Day Demand =3,260.3 GPD (residential + commercial)
P =0.0506 (equivalent population/1000)
Peaking Factor =4.31
Peak Sewer Demand =14,063.8 GPD (avg. day demand)*(peaking factor)
+ Infiltration Flow =135.0 GPD (not peaked)
Total Peak Flow =14198.8 GPD (residential + commercial + infiltration)
Peak Sewer Flow =9.86 GPM (peak flow)/(24 hrs/day)/(60 min/hr)
Values per C.O.B.
2015 Wastewater Facility Plan
𝑄𝑚𝑎𝑥
𝑄𝑎𝑣𝑔
=18 +𝑠ℎ𝑛𝑠𝑠𝑎𝑛𝑑𝑠𝑛𝑑𝑛𝑑𝑛𝑛𝑙𝑑1/2
4 +𝑠ℎ𝑛𝑠𝑠𝑎𝑛𝑑𝑠𝑛𝑑𝑛𝑑𝑛𝑛𝑙𝑑1/2
Rouse Block B Condiminiums
Date: 05.02.2024
6" Sewer Service Pipe Capacity
Input Values
d =0.50 ft =6"
y =0.375 ft =75%
Calculated Values (Equations from Fluid Mechanics by Chow)
Theta (Θ)4.19 rad 2*arccos(1-y/(d/2))
Area (A)0.16 ft2 (1/8)*(Θ-sinΘ)d2
Wetted Perimeter (P)1.05 ft 0.5Θd
Hydraulic Radius (R )0.15 ft (.25)*(1-(sinΘ)/Θ)d
Top Width (T)0.43 ft (sin 0.5Θ)d
Mannings Equation (Equation from Fundamentals of Mechanics by Munson)
n =0.013 (per COB Design Standards)
S0 =0.0104 ft/ft (min. 1/8" per foot for 6" services)
Q =0.52 cfs Q = 1.49/n*A*R2/3*S00.5
Q =235.0 gpm Q gpm = (Q cfs)(7.48 gal/ft3)(60 sec/min)
V =3.31 ft/s V = Q/A
Results A 6" diameter sewer service at the min. 1/8" per foot slope flowing
75% full has the capacity for 235.0 gpm.
Appendix C
Storm Water Drainage Basin Map
Storm Water Calculations
GWIC Well Log Report
Monitoring Well Data
BASIN 1:CAVE = 0.87I10 = 0.41A = 0.85 ACV10 = 2,192 CFRRV = 1,384 CF2024.05.15 B23-048 STORM BASINDESIGNED BY:QUALITY CHECK:JOB NO.FIELDBOOKDRAWN BY:DATE:REV DATE REVISION
ROUSE BLOCK B CONOMINIUMS
BOZEMAN, MONTANA
STORM DRAINAGE BASIN & RETENTION FACILITY SIZING
BASBASKLSB23-048SHEETEX-1.DWG5.15.2024NOT
FORCONSTRUCTIONSITE PLAN REVIEW
Rouse Block B Condiminiums
Date: 05.02.2024
Retention Volume Sizing Calcs
Rational Formula "C" Values Per MTDEQ 8 "C"
Impervious Area/Pond Surface 0.9
Gravel Area 0.8
Unimproved Area 0.3
Lawn/landscape 0.1
Post-Development Basin (C Value) Determinations:
Basin #Basin Description Total Area
(SF)
Total Area
(Acres)
Impervious
Area (SF)
Gravel
Area (SF)
Unimproved
Area (SF)
Landscape
Area (SF)
Composite
Cave
1 New Building 37,242 0.85 34,834 1,071 0 1,336 0.87
Runoff Volume Calcs (10-yr, 2-hr):
Basin #Basin Description Total Area
(SF)
Total Area
(Acres)
Composite
Cave
CCf
(Cf = 1.0)
10 yr - 2hr
i
(in/hr)
Flow
Q10
(cfs)
Volume
V10
(cf)
1 New Building 37,242 0.85 0.87 0.87 0.41 0.30 2,192
Rouse Block B Condiminiums
Date: 05.02.2024
Basin RRV (First 0.5") Calculations
Post-Development Condition:
Basin #Description Total
Area (SF)
Total
Area (AC)
Impervious
Area (SF)
Gravel
Area (SF)
Unimproved
Area (SF)
Landscape
Area (SF)
1 New Building 37,242 0.85 34,834 1,071 0 1,336
Runoff Reduction Volume (First 0.5" of Rainfall):
P =0.5 Inches (Water Quality Rainfall Depth)
Rv =0.89 (Dimensionless Runoff Coefficient, Rv=0.05+0.9(I)
I =93.5%(Percent Impervious Area Draining to Facility)
A =0.85 AC (Total Drainage Area)
RRV =0.032 AC-FT (Runoff Reduction Volume)*
1,384 CF
*RRV = PRvA/12 per Montana Post-Construction Storm Water BMP Design Guidance Manual Eq. 3-1
Rouse Block B Ground Water Monitoring
GW Well 3/22/2024 3/29/2024 4/5/2024 4/12/2024 4/19/2024 4/26/2024 5/3/2024 5/10/2024 5/17/2024 5/24/2024 5/31/2024 6/7/2024
B-2 22.10 21.70 21.40 21.04 20.76 20.53 20.13 19.25 17.62
Depth to Ground Water (ft)
10.00
12.00
14.00
16.00
18.00
20.00
22.00
24.00
3/9/2024 3/19/2024 3/29/2024 4/8/2024 4/18/2024 4/28/2024 5/8/2024 5/18/2024 5/28/2024 6/7/2024 6/17/2024
Depth to Groundwater (Ft)Date (Month, Day, Year)
Ground Water Depths
B-2