HomeMy WebLinkAbout9c NWX WatercourseCompliance ltr 12-30-19
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Danielle Garber, AICP
Associate Planner
City of Bozeman
20 East Olive St.
PO Box 1230
Bozeman, MT 59771
December 30, 2019
RE: Northwest Crossing Wetland and Watercourse Regulation Conformance
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Dear Sarah,
The Northwest Crossing Subdivision proposed site plan submittal has been reviewed for adherence to
City of Bozeman watercourse regulations. Homestead Park Vision plans were reviewed, no information
regarding the area west of Homestead Park has been received. The following is a summary (•) of the
watercourse regulations conformance analysis.
➢ Delineation Report
• Reference is made to floodplain map in the delineation report. Do the limits of the watercourse
setback equate the limits of the 100-year floodplain?
• The aquatic resources map included in the report requires the following edits (but not limited to):
o a map title, figure number, date of delineation, and author(s) of mapping/delineation;
o a legend (ID all line types, abbreviations, wetland type features, channel bed symbol,
COE sample point label, etc.);
o wetland areas are not differentiated from upland areas (use cross hatching or other
method to illustrate wetlands);
o streambed ordinary highwater marks (OHWM) are not illustrated (OHWM should have
been surveyed);
o there are actually three (3) streambed channels within the project site, these channels
require differentiation; name (or unnamed); linear feet; source, purpose (e.g. if an
irrigation ditch, supplemented with irrigation water, or is a naturally flowing perennial
stream), average width, whether vegetated, etc.;
o acreages of wetlands are not included on the map (use callouts or table);
o do the wetland acreages in the report include area of streambed (they should not):
calculate streambed area and linear feet of channel centerline separate from wetland
acreage;
o names of streambeds are not included (identify as “unnamed” if feature has no official
name);
o use callouts to identify streambed identifier and linear feet of centerline to the nearest
foot (estimates are not acceptable);
o off-site wetlands must also be delineated within 50 feet of the project boundary or
estimated if access is prohibited (is there a wetland east of the southeast property corner,
or anywhere outside of the entire east boundary?);
o wetland buffers along off-site aquatic resources (within 50ft beyond project boundary)
must be extended into the proposed property;
o the map requires a north arrow; and,
o COE sample points must be illustrated on the delineation map.
Headwaters Academy, Inc. Wetland and Watercourse Regulation Conformance December 30, 2019
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o NOTE: The separately submitted Northwest Crossing Subdivision Surface Water and
Wetlands Locations Map (C120) does include more pertinent data, however most all
comments pertaining to the aquatic resources map in the report above apply to this map.
• No sample points were apparently established in wetlands identified by NWI or low areas in east
half of the project site. Were these areas examined?
➢ Exhibit: 5 MSP1.5 Homestead Park Vision
• It is unclear throughout exhibit 5 MSP1.5 Homestead Park Vision where Zone 2 Watercourse
Setback limits occur:
o What is the gray rectangle in the lower SW corner (“Oak Grove”)?
o What is the gray feature depicted on the south side of the Zone 2 setback area and below the
word “Park 1”?
o It appears that some areas of Zone 2 will be utilized by homeowners (as indicated by
perpendicular trails (?) leading to the main trail)? How will these areas be protected from
fill?
o “Maynard’s Crossing” and “Bluestem Corner” include a gray area within Zone 2, what are
these features?
o The intent of Zone 1 is to leave unmaintained, except for weed control, will Zone 1 be left
unmowed?
o Are there stormwater treatment facilities within the watercourse setback?
➢ Exhibit: Northwest Crossing Landscape Framework
• No watercourse setback planting plan was included in the submittal for either Baxter Ditch or the
Unnamed channels (Zone 1: 100% of area shall be planted with 1 shrub/10ft; and 1 tree/30ft of
channel bed).
• What grass species will be used in the watercourse setbacks?
➢ Environmental Permitting
• The design plans indicate Baxter Creek wetland and streambed crossings (are there crossings
proposed for the west boundary watercourses?). Have Section 404, MDEQ 401, or MT310
permits been acquired?
• Is a Floodplain Permit required?
I would like the opportunity to provide a final review of this project after deficits have been remedied.
Please contact me with any questions regarding the enclosed analysis and summary (406-580-6993;
lbacon@terraquaticllc.com ). I am available for meetings with the developer, City Planners, or to attend
Commission meetings.
Sincerely,
Lynn M. Bacon, PWS
TerraQuatic, LLC
614 west Lamme Street
Bozeman, MT 59715
(406) 580-6993lbacon@terraquaticllc.com