HomeMy WebLinkAboutUF Phase 2 Wetland NarrativeUrban + Farm City of Bozeman Aquatic Resource Submittal: Prepared by Sundog Ecological Inc. DATE 04/04/2023
Sec. 38.410.100. - Watercourse setback. (38.23.100)
A. Where a development is crossed by or is adjacent to a watercourse, the developer must mitigate the impacts of the
development on the watercourse. This mitigation may not be less restrictive than the requirements of the city
floodplain regulations or any other applicable regulation of this chapter. The purpose of this mitigation is bank
stabilization; sediment, nutrient and pollution removal; and flood control.
1. Setback for developments granted preliminary plan or plat approval prior to July 10, 2002. These provisions apply to
all developments granted preliminary plan or plat approval prior to July 10, 2002, including applicable subdivision
exemptions:
a. Setbacks. A minimum 100-foot setback must be provided along both sides of the East Gallatin River. A minimum 35-
foot setback must be provided along both sides of all other watercourses.
(1) A portion of the required setback, immediately adjacent to the ordinary high water mark, must be left in a natural
vegetative state as follows:
(a) East Gallatin River — 50 feet.
(b) Other watercourses — five feet.
(2) No fence, residential or commercial structure, fill material, parking or other similar improvements shall be located
within required watercourse setbacks.
(3) All watercourse setbacks must be measured from the ordinary high water mark as defined in section 38.700.090.
When no ordinary high water mark is discernible, setbacks must be measured from the top of the stream bank.
2. Setbacks for developments granted preliminary plan or plat approval on or after July 10, 2002.
These provisions apply to all developments granted preliminary plat or plan approval on or after
July 10, 2002:
a. In the event a site with an existing development, that is subject to subsection 1 of this section, is submitted to the city
for a review subject to divisions 38.230, 430 and 270 of this chapter after July 10, 2002, the proposed development
must comply with this subsection 2 to the extent reasonably feasible given the existing site conditions. The final
approval body for the proposed development must determine the extent that is reasonably feasible, subject to
any appeal provisions that may apply. Such administrative relief must not reduce setbacks below those provided for in
subsection 1 of this section.
b. In addition to any relaxation of watercourse setbacks provided by subsection 2.a of this section, nothing in this
section prohibits an owner of affected property from:
(1) Applying for a variance to dimensional standards of the watercourse setbacks as allowed by and subject to the
requirements of division 38.250 of this chapter;
(2) When applicable, seeking a deviation to dimensional standards of the watercourse setback as allowed by and
subject to the requirements of divisions 38.340 or 430 of this chapter;
(3) Combining two or more lots to assemble a larger and more usable parcel;
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(4) Petitioning the state department of fish, wildlife and parks and the county water
conservation district to seek the reclassification of the relevant watercourse as an
irrigation facility not subject to the requirements of this section;
(5) After receipt of required permits, relocating the watercourse; or
(6) Pursuing any other lawful means of relief from the effects of this section.
c. Setbacks. Unless otherwise specified in subsection 2.e of this section, the following setback
requirements must be met:
(1) East Gallatin River. A minimum 100-foot setback must be provided along both sides of
the East Gallatin River.
(2) Sourdough/Bozeman Creek and Bridger Creek. A minimum 75-foot setback must be
provided along both sides of Sourdough/Bozeman and Bridger Creeks.
Urban + Farm City of Bozeman Aquatic Resource Submittal: Prepared by Sundog Ecological Inc. DATE 04/04/2023
(3) Other watercourses. A minimum 50-foot setback must be provided along both sides of
all other watercourses. A 50-foot setback is in place along the entirety of the east and west side of Baxter Creek. The
full extent of wetlands along the west side of Baxter Creek is not impacted. Along the east side of Baxter Creek the
wetland setback extends from the 50 watercourse setback along Lot 2 Block 11, which will be a future City of
Bozeman fire station (0.82 acres of wetland impacts). The wetland setback along Lot 1 Block 2, which will be
affordable housing, is 50 feet from the wetland edge, with exception of a small area that extended into this parcel
(0.10 wetland acres impacted).
The unnamed ditch, a jurisdictional waterway according to the City and Gallatin Conservation District, is being
rerouted along Huffine Lane. While this ditch has been considered jurisdictional by these two entities, this waterway
has no defined bed or bank, is highly vegetated with reed canary grass and does not currently connect to Baxter
Creek, but rather disappears underground. By rerouting the unnamed ditch, we will be adding channel reestablishing
wetland vegetation along the toes and banks and adding riparian shrub and tree plantings along the extend of its
corridor. Setback along the north side of the ditch are 50 feet, while setbacks along the south side of the ditch are
limited. This modification was necessary in order to have the ditch flow along the multiuse path and to more readily
bring the ditch back in Baxter Creek.
(4) All required watercourse setbacks must be extended as necessary to address these
additional requirements. All watercourse setbacks have been adjusted accordingly with exceptions noted above.
(a) The setback must extend to the edge of any delineated 100-year floodplain if the
floodplain is larger than the setbacks established in this subsection 2.c; N/A
(b) The setback must include immediately adjacent wetlands (i.e., fringe). The buffer
width must be extended by the width of the wetland; Yes, the buffer along Baxter Creek is extended by 50 feet along
the west side of the waterway. Variations along the east side of the waterway are noted above. Setbacks along the
rerouted ditch are based off the top of stream bank as specified in Section 38.700.090 and will extend 50 feet along
the north boundary and at varying distances along the south boundary.
(c) Areas with a slope greater than 33 percent do not count towards the width of the
setback; and N/A
(d) The setback must include connected wetlands. The buffer width must be extended
by a minimum of 50 feet beyond the perimeter of the connected wetlands. Yes, wetland setbacks are 50-feet beyond
the connected wetlands, with the exceptions noted above.
(5) All watercourse setbacks must be measured from the ordinary high water mark as
defined in section 38.700.090. When no ordinary high water mark is discernible,
setbacks must be measured from the top of the stream bank. Yes, see notes above.
d. No newly constructed residential or commercial structure, addition to an existing structure,
fence, deck, fill material (other than that required for exempt uses), parking lot or other
impervious surfaces, or other similar improvements may be located within required
watercourse setbacks, unless approved through, and in conformance with, a variance or
deviation process as authorized in this chapter. Yes, see explanation under exceptions.
Urban + Farm City of Bozeman Aquatic Resource Submittal: Prepared by Sundog Ecological Inc. DATE 04/04/2023
e. Exceptions. The watercourse setback is divided into two zones. Zone 1 consists of the 60
percent of the setback closest to the watercourse, and Zone 2 consists of the 40 percent of
the setback furthest from the watercourse. Yes.
(1) On-site stormwater treatment facilities may be located in Zone 2. Yes, all stormwater facilities that are within Zone
2 are located on the maps provided.
(2) Trails and trail-related improvements may be placed within the required watercourse
setback subject to the following provisions:
(a) Trails, and trail-related improvements such as benches and trail signage, may be
placed in Zone 2; Yes, trails are in Zone 2, see map.
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(b) Limited, non-looping developed spur trails to the water's edge may cross all zones.
Benches and limited informational/interpretive signage may be placed in Zone 1 at
the terminus of spur trails; There are no spur trails proposed for the project area.
(c) Due to topography, avoidance of wetlands, or other geographical constraints,
portions of non-spur trails may need to be placed within Zone 1. Trail construction
within Zone 1, inclusive of watercourse crossings and spur trails, per each side of
the watercourse, may not exceed the length of 300 percent of the width of the
applicable watercourse setback per 500 lineal feet of watercourse;
There are no spur trails proposed for the project area, no trails are located in Zone 1, trails are only within the Zone 2
setback.
(d) All trails must be constructed to minimize bank instability, sedimentation, nutrient
and pollution runoff. Trails must be aligned to minimize damage to plant and wildlife
habitat; and N/A
(e) Trails crossing the watercourse and trail-related bridge structures may be located
within all zones provided that the appropriate local, state and federal permits are
obtained. There are no spur trails proposed for the project area, no trails cross the watercourse, all trails are in the
Zone 2 setback.
(3) Streets, sidewalks, utility lines or similar public construction may be permitted within all
zones for the purpose of crossing a watercourse or protecting public health and safety.
The following practices must be observed:
(a) Crossings must be minimized to the greatest extent feasible; Yes, crossings have been minimized to the extent
possible.
Urban + Farm City of Bozeman Aquatic Resource Submittal: Prepared by Sundog Ecological Inc. DATE 04/04/2023
(b) Crossings with direct angles (90 degrees) must be used to the greatest extent
feasible instead of oblique crossing angles; Yes, crossing at Competition Drive is at 90 degrees.
(c) Construction must be capable of withstanding 100-year flood events; Yes, however not located within mapped 100-
year floodplain area.
(d) The subdivision grading and drainage plan must be designed to prevent the discharge
of untreated stormwater into a watercourse; and Yes, these materials have been submitted with the Plat materials.
(e) A bank stabilization plan for all public construction watercourse crossings must be
prepared and approved by the city prior to site preparation and installation of the
improvement. Yes, the crossing will be protected and have adequate bank stabilization.
(4) Outlets from stormwater treatment facilities may pass through all zones in order to
discharge to the receiving watercourse, provided that all required permits are obtained. Yes.
(5) Control of noxious weeds is required and activities required within limits outlined in any
approved noxious weed control plan may occur in all zones. Yes, a weed mitigation plan has been planned for the site
and was submitted with the Plat materials.
f. Setback planting. A setback planting plan must be prepared by a qualified landscape
professional, and must be reviewed and approved by the community development
department prior to the commencement of development or site preparation. The plan must
include a schedule, and plantings must be depicted on the plan as follows:
(1) Zone 1: Zone 1 must be planted with new or existing native materials suited for a
riparian area based on the following calculations. One hundred percent of the disturbed
areas of Zone 1 must be planted with a ground cover of native riparian sedges, forbs
and grasses suited for the area. In addition, a minimum of one shrub for every ten linear
feet and one tree for every 30 linear feet of the watercourse is required along each side
of the watercourse. Grouping or clumping of trees and shrubs as appropriate in a
riparian area is encouraged. Species that are appropriate to the soil hydrologic
conditions (wetness of soil and depth to the water table) must be used. Tree and shrub
species selected must be suitable for the climate and for planting in a riparian area with
an emphasis on native species. The Natural Resources Conservation Service (NRCS),
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the state native plant society and the county local water quality district (LWQD) are
Urban + Farm City of Bozeman Aquatic Resource Submittal: Prepared by Sundog Ecological Inc. DATE 04/04/2023
good sources of landscaping materials and/or landscaping information. Yes, a planting plan has been submitted for the
Zoned wetland areas of the site. Further wetland and riparian plantings are planned for the Baxter Creek restoration
corridor.
(2) Zone 2: Disturbed areas of Zone 2 must be planted with new or existing native grasses
suited for the area. Yes, a planting plan has been submitted for Zoned setback areas. Further wetland and riparian
plantings are planned for the Baxter Creek restoration corridor.
(3) Maintenance of the watercourse setback landscaping is required. If it can be
demonstrated that irrigation is present for the trees and shrubs, and fencing is provided
for the trees and shrubs, the number of required trees may be reduced to one tree for
every 60 linear feet and one shrub for every 20 linear feet of the watercourse along
each side of the watercourse. Approximately 300 shrubs and 80 trees will be planted along the restored Baxter Creek
corridor. Plantings will also be installed along the rerouted unnamed ditch section, as well as wetland vegetated
bank toes, and drill seeding in all disturbed areas.
(4) Planting materials are exempt from the size requirements of section 38.550.050.G.3.
(5) To prevent soil erosion and the invasion of noxious weeds, the watercourse setbacks
on all land proposed for development must be covered with existing vegetation or must
be seeded with native grasses as soon as seasonally feasible or prior to commencement
of any site development or site preparation work. All disturbed areas that are located within the Zone 1 and Zone 2
setback will be reseeded. Areas within the setback not within Zones 1 and 2 (wetlands) will be reseeded with a
facultative or wetter, native seed mix selected by the project wetland scientist.
(6) Native must mean those plants which are native to the Gallatin Valley. Yes.
(7) Use native grasses, forbs, sedges and other herbaceous plants in areas of disturbance
(e.g., bridges, culverts, utilities installation, trails) within the watercourse setback. Native
woody plantings are required in all zones in both disturbed and undisturbed areas. Yes.
g. Except as otherwise allowed in subsections 2.e and f of this section, no disturbance of soils
and existing vegetation shall occur in any zones.
3. Other provisions.
a. The watercourse setback must be depicted on all preliminary and final plats and plans. Yes.
b. These provisions do not apply to agricultural uses, including lands controlled in the
conservation reserve program (CRP), and activities and structures that existed prior to the
effective date of the ordinance from which this section is derived. Any agricultural uses,
activities or structures established after the effective date of the ordinance from which this
section is derived must comply with these regulations. An agricultural use, activity or
structure is considered abandoned if not used for agricultural purposes for more than 180
Urban + Farm City of Bozeman Aquatic Resource Submittal: Prepared by Sundog Ecological Inc. DATE 04/04/2023
consecutive days. N/A