HomeMy WebLinkAbout16-RMF - Stormwater Waiver Request
(406) 586-5599
714 Stoneridge Drive, Suite 3
Bozeman, MT 59718
Page 1
September 11, 2025
ATTN: Alicia Paz-Solis
City of Bozeman Engineering Department
20 E. Olive St.
Bozeman, MT 59715
Re: Rocky Mountain Flats, Bozeman, MT
Waiver Request from City of Bozeman Design & Construction Standards Sec. 6.8.3.A.d
Dear Alicia,
This letter and the enclosed exhibits have been prepared as a waiver request from COB DCS Sec. 6.8.3.A.d
for the Rocky Mountain Flats project. This section of the city standards requires stormwater infiltration
basins to be a minimum of 2 feet above the estimated seasonal high groundwater table to allow for
infiltration of stormwater. Due to the existing site constraints explained below, this 2-foot minimum
separation cannot be met for several of the proposed stormwater facilities, so we are seeking a waiver
from the standard.
BACKGROUND
The property is largely comprised of open field that was historically in agricultural use. The property
generally slopes from south to north at approximately 1.5-2% and is in an area of town that is known to
have a high seasonal groundwater table. Groundwater monitoring was performed on the property from
April to August 2022 and the results indicate that seasonal high groundwater (SHGW) peaked in early June
at depths of approximately 2.5’-3.5’ bgs.
Fowler Lane bounds the property to the west, and Meah Lane and S 31st Ave are stubbed to the property
to the southeast. Edgerton Ave and Gabriel Ave (local streets) were constructed to the north of the
project site as part of the adjacent Buffalo Run Development, and currently dead end at the northern
property boundary. All of these street sections will either be widened or extended into the property as
part of the proposed project.
Edgerton and Gabriel will extend south, upgradient to connect to the extension of Meah Lane. Since the
site slopes from south to north, runoff from Gabriel and Edgerton will flow toward the northern property
boundary and will need to be captured for treatment. These two locations, the stormwater on Edgerton
and Gabriel, are where designing storm systems 2’ above the SHGW table is unrealistic.
Two additional overflow retention ponds (#2-1 and #2-2) on the northern property line are not set 2’
above SHGW either. These ponds are directly adjacent to the property line, so their rim elevations were
Page 2
set so they could be graded to tie into existing grade at the property line. Since the SHGW elevation in this
location is approximately 2’ below existing grade, the bottom of pond elevations would need to be set at
the property boundary elevation in order to maintain 2’ separation to SHGW, which is not realistic.
These two ponds are only designed to provide overflow capacity during the 100-year storm event, and
will not receive runoff otherwise. The drainage areas contributing to these ponds have a series of
Stormtech chambers that are set 2’ above SHGW to treat the 10-year minor storm event. The COB DCS
allows stormwater runoff from the 100-yr event to pond in parking lots and other areas on site and does
not specify that this overflow ponding needs to be 2’ above SHGW. Therefore, we do not believe that a
waiver request is necessary for these overflow ponds.
PROBLEM DEFINED
The south ends of both the Edgerton Ave and Gabriel Ave street sections at the northern property line
were constructed to approximately the same elevation as the adjacent ground/pasture. In this area,
groundwater monitoring results indicate that the SHGW table is approximately 3.5’ below grade at the
connection to Edgerton and only approximately 2.5’ below grade at the connection to Gabriel. Since the
road surfaces were installed to existing grade, this places SHGW approximately 3.5’ and 2.5’ below the
existing asphalt surface of these respective streets at the northern property line.
In order for curb inlet structures to be constructible and meet city standards, the minimum height from
the curb gutter to the invert out of the structure for a 12” pipe is approximately 2.5’. Therefore, before
accounting for any pipe slope, the pipe inverts of structures at these road connections would be at SHGW
level on Gabriel and 1’ above SHGW on Edgerton. This means that ponds accepting runoff from curb inlets
at these locations would not be able to be constructed above SHGW, and certainly not 2’ above SHGW.
Fortunately, according to the stormwater design report for the Buffalo Run Development, the existing
storm sewer systems that serve Edgerton and Gabriel to the north of the project site each have a small
amount of additional capacity to allow them to accommodate additional street runoff. This allows the
inlets in Edgerton and Gabriel for this project to be shifted south of the property line and further up slope,
allowing separation of the ponds from SHGW. Shifting these inlets south while placing the ponds on the
property line downslope of the inlets, allowed the inlet pipes to slope down to the ponds while keeping
the ponds above the seasonal high groundwater table. Refer to the storm plan and profiles in the attached
Exhibits for reference of the relationship between the inlets, storm sewer pipes, the ponds, and the
groundwater table.
The inlets were shifted as far south on the streets as they could be shifted without exceeding the extra
capacity that was available in the existing systems to the north. This resulted in the inlets in Edgerton
being shifted approximately 83’ south of the property line while the inlets in Gabriel were shifted
approximately 105’ south of the property line. With the inlets at these locations and their outlet pipes
running to the ponds at 0.50% minimum slope, the receiving ponds are both able to be set slightly above
the estimated SHGW table.
DESIGN ALTERNATIVES
Since the receiving inlets cannot be shifted any farther south (uphill) on the streets, and the receiving
storm sewer pipes are set as shallow as possible, the only remaining option to raise the ponds to be 2’
above the SHGW table would be to raise the roads at the locations of these inlets. Storm System (Pond)
Page 3
#6 serving Edgerton is 0.40’ above SHGW, while Storm System (Pond) #9 serving Gabriel is 0.20’ above
SHGW. So, these ponds would need to be raised by approximately 1.6’ and 1.8’ respectively to meet the
2’ minimum requirement.
It can be assumed that in order to gain this additional elevation, the roads would need to be raised a
corresponding amount at the inlets. Raising these roads by this much while still tying into the existing
street sections at the property lines creates an unrealistic centerline grade on the streets that does not
meet city design standards for vertical curves or grade changes. The red line on the road profiles in the
exhibits shows an example of a centerline profile that would be needed to raise the road by the required
amount at the storm inlets while tying in to the existing street stubs.
Since the Buffalo Run development to the north is a dense, multi-family development with walkways,
drive approaches, and buildings connecting to or directly adjacent to these streets, we don’t believe that
demolishing and re-grading portions of the existing streets to raise the street connections at the property
line would be a realistic option.
Lastly, the ponds on the northern property lines need to be able to be graded to tie into existing and
adjacent grade at the property line. So, even if the roads and ponds could be raised, the ponds would end
up “perched” above the existing grade at the property lines.
For these reasons, we feel that setting the ponds above SHGW, but not 2’ above SHGW is the most realistic
alternative.
ADMINISTRATIVE WAIVER REVIEW CRITERIA
Following are responses to the three criteria outlined in Section 1.9.2 of the COB DCS that are used to
evaluate a waiver request:
A. The deviation from standards is not in conflict with applicable state and federal codes and
requirements.
Although general “industry guidance” recommends a setting stormwater facilities above
groundwater, there is not, to our knowledge, a state or federal code that sets a specific minimum
separation from groundwater.
In fact, until last year, the City design standards did not include a minimum separation of
stormwater facilities from groundwater. Therefore, any previous project in the city that applied
for a site plan application prior to January 2024 was able to set stormwater facilities within 2’ of
the water table as we are proposing in this waiver. If this site plan application had been submitted
less than a year earlier, a waiver request from this standard would not be required for this design.
B. The deviation from standards will not harm, or will be beneficial to, the public in general.
This deviation is not expected to harm the public. Since the city did not have this requirement in
their previous standards last year and since groundwater is extremely high across most of the city,
the majority of stormwater facilities in the city are within 2’ of the water table. This waiver would
simply allow these several stormwater facilities to be installed in a similar manner to the majority
Page 4
of systems in the city and in accordance with the old standards instead of meeting the new
standard.
C. The deviation from standards is consistent with the general purpose of standards to protect
public health and safety and promote operational efficiency while minimizing life-cycle costs of
public infrastructure.
Yes, the deviation is consistent with the general purpose of standards for all the above reasons.
As explained previously, receiving this deviation would allow the streets to be graded in a way
that meets city design standards for vertical geometry, which were put in place to protect public
health and safety. The stormwater facilities as proposed would be installed in a similar
configuration as stormwater facilities across the city were installed up until last year. To our
knowledge, the majority of the stormwater facilities in the city that are currently constructed in
this manner are not a risk to public health and safety.
The recently received city comments on the site plan application indicated that the city does not
intent to accept maintenance responsibilities for these facilities. So, since these facilities will be
privately maintained, minimization of life cycle costs for public infrastructure is not a concern for
this deviation. Even if these facilities do switch to being maintained by the city in the future, they
are shallow stormwater ponds, so maintenance of them is relatively simple, regardless of their
proximity to the water table.
SUMMARY
Lastly, it should be noted that the remainder of the project design adheres to the new COB DCS
stormwater standards, and the developer and the design team has gone to great expense to ensure these
standards are met.
With the exception of the few stormwater ponds located at the property line, the remainder of the
stormwater facilities proposed on the project, serving both the private and public improvements, are set
2’ above SHGW. These facilities are almost all located within parking lots in front of the buildings in low
profile Stormtech chamber systems. Since they are under parking lots, setting these facilities 2’ above
SHGW has required the parking lots to be designed, on average, 2’-3’ above existing grade and the
adjacent buildings to be set anywhere from 3’-7’ above existing grade. In short, requiring the stormwater
facilities to be 2’ above SHGW is resulting in almost entire site (roads, buildings, and parking lots) being
raised by 2’. The requirement to retain the 100-year storm event on site has also resulted in significant
increases to the sizes of the proposed stormwater facilities. Adherence to the just these two new
stormwater standards alone is resulting in of hundreds of thousands of dollars in cost increases to an
affordable housing project.
We are aware that cost to the developer is not something that can be considered when reviewing a waiver
request. However, we feel it is important to point out that the applicant is not requesting this waiver in
order to cut costs. The new standards are being met anywhere on site where it is feasible, regardless of
the cost to the project.
Instead, the reason for this waiver is to allow the applicant to capture the required amount of stormwater
on site while connecting to existing street stubs that were set too low to allow a stormwater design that
Page 5
meets current standards. The elevation of these existing street stubs were reviewed and approved by the
city under the old standards, so we feel it is appropriate that the city allow this waiver so we can connect
to them with a stormwater design that also meets the old standards.
Sincerely,
Ethan Cote, PE
Alpine Surveying & Engineering, Inc.
ELECELECELECGASGASGASELEC ELEC ELEC
CO CO
DSDS
DS
DS
DSSTSTSTST 8''SS8''SS8''SS8''W8''W8''W8''W8''WSS
ST
ST
ST
ST
ST
STSTST
ST
8''SS 8''SS
W V
FW V
8''SS
ST
GASGASGASGASGAS8''W 8''W 8''W 8''W 8''W 8''W 8''W 8''W 8''W 8''W8''W6''W8''SSW VW VHYD15''SS15''SS15''SS15''SS15''SS15''SSGASUGPUGPUGPUGPUGPUGP UGP UGP UGP UGP UGP UGP UGP UGP UGP UGP
ST0+00 1+00 2+00
3+00
4+004+41
INSTALL FES
INV OUT:5004.00
STA: 2+29.40
ST 6-1 (PC) (36"x2')
STA: 4+36.1 OFF:0.0'R
TBC: 5008.42
RIM: 5007.91
INV OUT: 5005.30 (12")(W)
ST 6-2 (PC) (4.0')
STA: 4+03.0 OFF:0.2'R
TBC: 5008.46
RIM: 5007.95
INV IN: 5005.14 (12")(E)
INV OUT: 5004.89 (15")(NW)
ST 6-3 (PC) (4.0')
STA:3+45.4 OFF:0.0R
RIM:5008.05
INV IN:5004.60 (15")(SE)
INV OUT:5004.60 (15")(W)500850095008
500
9
5005
5006
5007
5008
5009 500
7
5
0
0
8
PROPOSED STORMWATER EASEMENT
STORM SYSTEM #6 (RETENTION POND)
TOP OF POND ELEV:5005.40
BOT OF POND ELEV:5003.90
APPROX. S.H.G.W. ELEV.:5003.50
4H:1V SIDE SLOPES W/ 1.5' WATER DEPTH
EX. 35' LOCAL STREET
LOCAL STREET TO BE SAW CUT AND EXTENDED SOUTH INTO SITE.
CURB LIP AT ENDS OF EX STREET SECTION (EA SPOT GRADE) WERE
CONSTRUCTED AT APPROXIMATE GRADE OF ADJACENT FIELD.
SEASONAL HIGH GROUNDWATER ELEVATION (GW SPOT GRADE) IS
~3.5' BELOW EXISTING GRADE IN THIS AREA
5007
50085007(6.58 EA)
(3.17 GW)[6.68][6.78][6.35][6.26][6.62]
(6.80 EA)
(3.17 GW)
EX. GRADE AT PROPERTY LINE (TYP.)-2.9%
-2
.
0%
(6.98 EA)
83'
(8.21 EA)
4995
5000
5005
5010
5015
4995
5000
5005
5010
5015
0+505006.195003.901+005006.095003.901+505006.455003.902+005006.415003.902+505006.275007.323+005006.595007.603+505007.045008.114+005007.745008.42PROPOSED GRADE
EXISTING GRADE
8" PVC SAN. SEWER CROSSING.
MAINTAIN 12" MIN. SEPARATION
8" PVC SAN. SEWER CROSSING.
MAINTAIN 12" MIN. SEPARATION
8" PVC WATER CROSSING.
MAINTAIN 18" MIN. SEPARATION
116' of 15" RCP PIPE @ 0.52%
58' of 15" SDR 35 @ 0.50%
33' of 12" SDR 35 @ 0.50%
ST 6-1 (PC) (2'x3')
INV OUT:5005.30 (12") (W)
STA 4+36.1 (0.0'R)
TBC:5008.42
RIM:5007.91
ST 6-2 (PC) (4.0')
INV IN:5005.14 (12") (E)
INV OUT:5004.89 (15") (NW)
STA 4+03.0 (0.2'R)
TBC:5008.46
RIM:5007.95
ST 6-3 (PC) (4.0')
INV IN:5004.60 (15") (SE)
INV OUT:5004.60 (15") (W)
STA 3+45.4 (0.0'R)
RIM:5008.05
INSTALL FES
STA:2+29.40
INV OUT:5004.00
STORM SYSTEM #6 (RETENTION POND)
TOP OF POND ELEV:5005.40
BOT OF POND ELEV:5003.90
APPROX. S.H.G.W. ELEV.:5003.50
4H:1V SIDE SLOPES W/ 1.5' WATER DEPTH
GW GW GW GW GW GW GW GW GW GW
GW
GW
2.6'
SEASONAL HIGH GW TABLE
0.40'
20'0 40'
SCALE 1" = 20'
N
STORM SEWER - EDGERTON1SCALE: HORIZONTAL 1"=20' VERTICAL 1"=2'
PROJECT NO:
DATE:
ENGINEER:
REVISIONS
DATENO.DESC.
SHEET OF
749-01
9/12/2025
ELC
1
2
3
4
5
6
7
8 ROCKY MOUNTAIN FLATSCITY OF BOZEMAN, MONTANAWAIVER REQUEST EXHIBIT4EDGERTON AVEBUILDING A
BUILDING BFOWLER LANEEX. 1EDGERTON AVENUE STORMWATER1
-INLETS SET AS FAR NORTH AS POSSIBLE TO CAPTURE AS MUCH STREET AS POSSIBLE
AND STILL BE ABLE TO CONVEY WATER TO A POND THAT IS ABOVE THE SHGW TABLE.
-ANY INLETS INSTALLED NORTH OF THIS POINT WILL NOT BE ABLE TO DAYLIGHT TO A
POND OR SUBSURFACE SYSTEM THAT IS ABOVE THE SHGW TABLE.
PIPES AT MINIMUM SLOPE TO CONVEY DESIGN STORM TO POND WHILE
KEEPING POND AS HIGH AS POSSIBLE ABOVE WATER TABLE
℄ GRADE OF EX. STREET = 0.60% PER SURVEY
-STORMWATER FROM THE STREET SECTION NORTH OF INLETS WILL FLOW NORTH TO
INLETS AND SYSTEM INSTALLED WITH BUFFALO RUN PROJECT. BASED ON CAPACITIES
SPECIFIED IN BUFFALO RUN DESIGN REPORT, THE EXISTING INLETS AND SYSTEM IN
BUFFALO RUN ONLY HAD EXTRA CAPACITY TO SUPPORT ~85 LF OF ADDITIONAL STREET.
-STREET AT THIS LOCATION WOULD NEED TO BE RAISED BY ~1.6' TO ALLOW INLETS TO
DRAIN TO POND SET 2' ABOVE SHGW. THIS WOULD RESULT IN A ROAD SLOPE OF ~4.6%
NORTH OF THESE INLETS, TYING INTO THE EXISTING STREET STUB THAT IS SLOPED AT
0.60%.
ELECELECCO 8''W8''W8''W8''W8''W8''W8''SS8''SS8''SS8''SS8''SS8''SSSS
ST STSTSTST4''W W V
W V
8''SS
8''W 8''W 8''W 8''W 8''W 8''W 8''W 8''WW V
HY DUGP UGP UGP UGP UGP UGP UGP UGP UGPUGP0+00 1+001+80
STORM SYSTEM #9 (RETENTION POND)
TOP OF POND ELEV:5008.00
BOT OF POND ELEV:5006.80
APPROX. S.H.G.W. ELEV.:5006.60
4H:1V SIDE SLOPES W/ 1.2' WATER DEPTH
ST 9-2 (PC) (4.0')
STA: 0+39.8 OFF:0.0'
TBC: 5010.71
RIM: 5010.20
INV IN: 5007.53 (12")(W)
INV OUT: 5007.33 (15")(N)
ST 9-1 (PC) (24"x3')
STA: 0+06.3 OFF:0.0'
TBC: 5010.73
RIM: 5010.22
INV OUT: 5007.70 (12")(E)
INSTALL FES
INV OUT:5006.85
STA: 1+31.39
5010
5009
5011
5010
5007
5007
5008
5008
5009
5011
SLOPE CONC.
CHASE @ -1.5%
PROPOSED STORMWATER EASEMENT
18" WIDE CONC. CURB CHASE
PER DETAIL 4/C9.3
(8.00)
(6.82)
(8.25)
(8.58 EA)
(6.13 GW)
(8.07 EA)
(5.98 GW)
104'
EX. 35' LOCAL STREET
EX. GRADE AT PROPERTY LINE (TYP.)
[8.35][7.99][8.73]
4995
5000
5005
5010
5015
4995
5000
5005
5010
5015
0+505009.735010.511+005009.015009.411+505008.385006.80PROPOSED GRADE
EXISTING GRADE
ST 9-2 (PC) (4.0')
INV IN:5007.53 (12") (W)
INV OUT:5007.33 (15") (N)
STA 0+39.8 (0.0')
TBC:5010.71
RIM:5010.20
ST 9-1 (PC) (3'x2')
INV OUT:5007.70 (12") (E)
STA 0+06.3 (0.0')
TBC:5010.73
RIM:5010.22
33' of 12" SDR 35 @ 0.50%
92' of 15" SDR 35 @ 0.52%
INSTALL FES
STA:1+31.39
INV OUT:5006.85
STORM SYSTEM #9 (RETENTION POND)
TOP OF POND ELEV:5008.00
BOT OF POND ELEV:5006.80
APPROX. S.H.G.W. ELEV.:5006.60
4H:1V SIDE SLOPES W/ 1.2' WATER DEPTH
GW
GW
GW
GW GW
2.5'
SEASONAL HIGH GW TABLE
0.20'
PROJECT NO:
DATE:
ENGINEER:
REVISIONS
DATENO.DESC.
SHEET OF
749-01
9/12/2025
ELC
1
2
3
4
5
6
7
8 ROCKY MOUNTAIN FLATSCITY OF BOZEMAN, MONTANAWAIVER REQUEST EXHIBIT4
STORM SEWER - SYSTEM 92
SCALE: HORIZONTAL 1"=20' VERTICAL 1"=2'GABRIEL AVEBUILDING C
20'0 40'
SCALE 1" = 20'
N
CITY PARK
-INLETS SET AS FAR NORTH AS POSSIBLE TO CAPTURE AS MUCH STREET AS POSSIBLE
AND STILL BE ABLE TO CONVEY WATER TO A POND THAT IS ABOVE THE SHGW TABLE.
-ANY INLETS INSTALLED NORTH OF THIS POINT WILL NOT BE ABLE TO DAYLIGHT TO A
POND OR SUBSURFACE SYSTEM THAT IS ABOVE THE SHGW TABLE.
PIPES AT MINIMUM SLOPE TO CONVEY DESIGN STORM TO POND WHILE
KEEPING POND AS HIGH AS POSSIBLE ABOVE WATER TABLE
℄ GRADE OF EX. STREET ~1% PER SURVEY
-STORMWATER FROM THE STREET SECTION NORTH OF INLETS WILL FLOW NORTH TO INLETS
AND SYSTEM INSTALLED WITH BUFFALO RUN PROJECT. BASED ON CAPACITIES SPECIFIED IN
BUFFALO RUN DESIGN REPORT, THE EXISTING INLETS AND SYSTEM IN BUFFALO RUN ONLY
HAD EXTRA CAPACITY TO SUPPORT ~105 LF OF ADDITIONAL STREET.
-STREET AT THIS LOCATION WOULD NEED TO BE RAISED BY ~1.8' TO ALLOW INLETS TO DRAIN
TO POND SET 2' ABOVE SHGW. THIS WOULD RESULT IN A ROAD SLOPE OF ~5.9% NORTH OF
THESE INLETS, TYING INTO THE EXISTING STREET STUB THAT IS SLOPED AT 1%.
LOCAL STREET TO BE SAW CUT AND EXTENDED SOUTH INTO SITE.
CURB LIP AT ENDS OF EX STREET SECTION (EA SPOT GRADE) WERE
CONSTRUCTED AT APPROXIMATE GRADE OF ADJACENT FIELD.
SEASONAL HIGH GROUNDWATER ELEVATION (GW SPOT GRADE) IS
~2.5' BELOW EXISTING GRADE IN THIS AREA
EX. 2GABRIEL AVENUE STORMWATER2
8''W8''W8''W8''W6''W8''W 8''W
8''SS8''SS8''SS8''SSXXXXXXXXXXXXXXXXXXXXXXXXW VW VHYDGAS GAS
UGP UGP UGP UGP UGP UGP UGP UGPELECELECELECELECELECELECELECELECELECELECGASGASGASGASGASGASGASGASGASGAS
ELEC ELEC ELEC ELECELECELECCOCODSELECELECELECELECELEC8''SS8''SS8''SS8''SS8''SS8''SS8''SS8''SS8''SS8''SS8''SS8''SS8''SS8''W8''W8''W8''W8''W8''W8''W8''W8''W8''W8''W8''W8''W8''W8''W8''W8''W8''W8''W8''WW VW V
W VSSHYDHY DW VW VSSSTSTSTSTSTST8''SS8''SSW VFW V8''SS0+001+002+003+004+005+00STA:4+35.32
STA:1+00.50
LIMIT OF PAVING 50105007.
0
5008.05009.05011.05012.05013.035' LOCAL
STREET
SECTIONR15'R15'R15'R15'EDGERTON AVE
60' PUBLIC STREET
AND UTILITY
EASEMENT
100' TRANSITION FROM PROPOSED
2% CROWN TO ≈3% CROWN OF EX.
STREET SECTION TO THE NORTH.
5' CONC. SIDEWALK (TYP.)
INSTALL DOUBLE GUTTER WITH
FILLETS PER DETAIL 1/C9.4 MEAH LANE2' INTEGRAL CONCRETE CURB AND
GUTTER PER DETAIL 1/C9.3
INSTALL DOUBLE ADA RAMP PER
DETAIL 2/C9.0 WITH TRUNCATED
DOME DETECTABLE WARNING
SURFACE (TYP.)
INSTALL NON-ARTERIAL DRIVE
APPROACH PER DETAIL 4/C9.0
SAWCUT EXISTING
CURB & ASPHALT
EX 35' LOCAL
STREET SECTION
BUFFALO RUN DRIVE APPROACH AND PARKING LOT
5000
5005
5010
5015
5020
5000
5005
5010
5015
5020
0+505013.541+005012.145012.831+505011.375012.502+005010.605011.442+505009.705010.373+005008.745009.313+505007.785008.254+005007.145007.514+505006.915006.905+00
-0.59%
-1.48%
2.00%-2.00%
-1.42%
-2.12%GRADE BREAK STA = 0+00.00ELEV = 5014.25GRADE BREAK STA = 1+15.50ELEV = 5012.61GRADE BREAK STA = 1+30.00ELEV = 5012.90GRADE BREAK STA = 1+44.50ELEV = 5012.61GRADE BREAK STA = 3+50.00ELEV = 5008.25GRADE BREAK STA = 4+35.25ELEV = 5006.99GRADE BREAK STA = 4+70.51ELEV = 5006.78EXISTING GRADE
PROPOSED ℄ GRADE
POTENTIAL FUTURE ℄ GRADE
EX. STREET ℄ GRADE
LIMIT OF EX. PAVING
-1.14%
-4.9
9
%
-1.63%GRADE BREAK STA = 1+44.50ELEV = 5012.61GRADE BREAK STA = 4+35.25ELEV = 5006.99PVI STA: 4+09.20
PVI ELEV: 5007.41
K: 10.00
LVC: 33.57
BVCS: 3+92.41BVCE: 5008.25EVCS: 4+25.99EVCE: 5007.14PVI STA: 3+52.63
PVI ELEV: 5010.23
K: 18.54
LVC: 71.23
BVCS: 3+17.02BVCE: 5010.64EVCS: 3+88.25EVCE: 5008.461.6'
K-VALUE DOES NOT MEET STANDARDS
TRANSITION SLOPE
℄ GRADE NEEDED TO RAISE INLETS/POND TO
PROVIDE 2' SEPARATION TO SHGW
0 30'60'
SCALE 1" = 30'NEDGERTON AVENUE PLAN & PROFILE1SCALE: HORIZONTAL 1"= 30' VERTICAL 1"= 3'
PROJECT NO:
DATE:
ENGINEER:
REVISIONS
DATENO.DESC.
SHEET OF
749-01
9/12/2025
ELC
1
2
3
4
5
6
7
8 ROCKY MOUNTAIN FLATSCITY OF BOZEMAN, MONTANAWAIVER REQUEST EXHIBIT4
BUILDING B
BUILDING A
EX. 3EDGERTON AVENUE PLAN & PROFILE3
8''W8''W8''W8''W8''W8''W8''SS8''SS8''SSXXXXXXXXXXXXXXXXXXXXXXXW VHYDUGPUGPUGPUGPUGPUGP UGP UGP UGP UGP UGP UGP UGP UGPELECELECCODSELEC
ELECELECELECELEC8''W8''W8''W8''W8''W8''W8''W8''W8''W8''W8''W8''W8''W8''W8''W8''W8''W8''W8''SS8''SS8''SS8''SS8''SS8''SS8''SS8''SS8''SS8''SS8''SS8''SS8''SSW VW VW VSSSSSTST
ST
ST
ST4''WW VW V8''SSELEC
HYD0+001+002+003+004+004+61.9750105009.05011.05012.05013.05014.060' PUBLIC
STREET AND
UTILITY
EASEMENTR15'R15'100' TRANSITION FROM PROPOSED
2% CROWN TO ≈3% CROWN OF EX.
STREET SECTION TO THE NORTH.
6' CONC. SIDEWALK
2' INTEGRAL CONCRETE CURB AND
GUTTER PER DETAIL 1/C9.3
35' LOCAL
STREET
SECTION
INSTALL SINGLE ADA RAMP PER DETAIL
1/C9.0 WITH TRUNCATED DOME
DETECTABLE WARNING SURFACE (TYP.)
INSTALL NON-ARTERIAL DRIVE
APPROACH PER DETAIL 4/C9.0
SAWCUT EXISTING
CURB & ASPHALT
EX 35' LOCAL
STREET SECTION
ADJACENT BUILDING ON BUFFALO RUN SITE
5005
5010
5015
5020
5005
5010
5015
5020
0+505013.095014.071+005012.355014.151+505011.645012.962+005010.855011.752+505009.985010.543+005009.175009.403+505008.455008.454+005007.955007.924+50 5+00
-1.91%
-0.97%
2.00%-2.00%-0.18%
-2.43%GRADE BREAK STA = 0+15.50ELEV = 5014.13GRADE BREAK STA = 0+77.47ELEV = 5014.02GRADE BREAK STA = 0+91.97ELEV = 5014.31GRADE BREAK STA = 1+06.47ELEV = 5014.02GRADE BREAK STA = 2+84.53ELEV = 5009.70GRADE BREAK STA = 3+54.86ELEV = 5008.36GRADE BREAK STA = 4+10.00ELEV = 5007.82STA: 0+91.97MEAH LANE DESIGN CL CROSSINGEXISTING GRADE
PROPOSED ℄ GRADE
POTENTIAL FUTURE ℄ GRADE
EXISTING STREET ℄ GRADE
LIMIT OF EX. PAVING
-1.06%
-5.
9
3
%
-1.91%GRADE BREAK STA = 1+06.47ELEV = 5014.02GRADE BREAK STA = 3+54.86ELEV = 5008.36PVI STA: 3+27.55
PVI ELEV: 5008.88
K: 10.00
LVC: 40.18
BVCS: 3+07.46BVCE: 5010.07EVCS: 3+47.64EVCE: 5008.49PVI STA: 2+70.14
PVI ELEV: 5012.28
K: 15.00
LVC: 73.03
BVCS: 2+33.63BVCE: 5012.67EVCS: 3+06.65EVCE: 5010.121.8'
K-VALUE DOES NOT MEET STANDARDS
TRANSITION SLOPE
℄ GRADE NEEDED TO RAISE INLETS/POND TO
PROVIDE 2' SEPARATION TO SHGW
EX. 4GABRIEL AVENUE STORMWATER0 30'60'
SCALE 1" = 30'N4
GABRIEL AVENUE PLAN & PROFILE1SCALE: HORIZONTAL 1"= 30' VERTICAL 1"= 3'
PROJECT NO:
DATE:
ENGINEER:
REVISIONS
DATENO.DESC.
SHEET OF
749-01
9/12/2025
ELC
1
2
3
4
5
6
7
8 ROCKY MOUNTAIN FLATSCITY OF BOZEMAN, MONTANAWAIVER REQUEST EXHIBIT4
GABRIEL AVENUEMEAH LANEBUILDING C
CITY PARK