HomeMy WebLinkAboutST2 - Valley Glass Stormwater Facilities O&M Plan
Valley Glass Site Plan – Stormwater Facilities Operation & Maintenance Plan Page 1
February 2024
STORMWATER FACILITIES OPERATION & MAINTENANCE PLAN
FOR: Valley Glass Site Plan
PROPERTY DESCRIPTION
Lot 3 of Tract 6 plus Vacated Single Tree Court,
Gardner Simmental Plaza Subdivision
Sec. 35, T1S, R5E, of PMM
City of Bozeman, Gallatin County, Montana
RESPONSIBLE PARTY
VGW Investments, LLC
2011 Fairway Drive
Bozeman, MT 59715
(406) 586-0581
STORMWATER FACILITIES DESCRIPTION
Storm Ponds: The storm ponds for the property were designed to capture runoff from the
adjacent street rights-of-way and portions of the commercial site. The ponds were designed with
4:1 max. side slopes and a maximum water storage depth of 1-1.5 ft. The ponds should be finish
graded with 6” of topsoil and fully vegetated with grass per the approved landscape plans.
Storm Chases: Concrete storm chases of varying widths are designed across the property to
convey runoff from parking lots and streets to ponds in locations where insufficient cover exists
to install storm inlets with pipes. The chases should be installed per City of Bozeman Standard
Drawing No. 02529-14 with a 6” minimum channel depth, and channel widths as specified on the
site plan.
Storm Sewer Network: Stormwater from the surrounding Right-of-Way will flow in the curbline
to curb chases located in the boulevard and sidewalk with a minimum 6” depth. This runoff will
then be directed in to inlet structure and ultimately unground infiltration chambers. On-site
runoff will flow to proposed inlet structures via sheet flow, curb and valley gutter.
Infiltration Chamber Systems: The proposed underground infiltration chambers area
combination of SC-160LP and SC-310 Arched Plastic Pipe by ADS. These systems, and the
surrounding washed gravel rock, retain runoff until it can be infiltrated in to the groundwater.
INSPECTION & MAINTENANCE SCHEDULE
The stormwater facilities on site will be inspected and maintained based on the below schedule.
Inspection and maintenance will be performed by the responsible party, the facility employees, or a
contracted third party.
Inspection: Routine inspection of stormwater facilities will include visual inspection to ensure the
facilities are functioning properly and there are no debris accumulated in or clogging the
Valley Glass Site Plan – Stormwater Facilities Operation & Maintenance Plan Page 2
February 2024
stormwater facilities. Inspections should also be performed after major storm events producing
approximately 0.5” of rainfall in a 24-hour period. These inspections shall include observations of
the above ground stormwater facilities for areas of erosion or areas of ponding, and removal of
accumulated trash or debris in facilities. The Stormtech systems Should be inspected by checking
the Stormtech isolator row for accumulated sediment.
Maintenance: Maintenance shall be performed as necessary based on inspections, and at regular
intervals throughout the year based on the schedule below.
Routine summer and fall maintenance to above ground facilities will generally include removal of
trash, grass clippings, leaves, accumulated sediment, and obstructions, and regular mowing of
vegetated facilities from May to October. Overgrown vegetation should regularly be trimmed
from around pipe and chase outlets during the summer and fall months to prevent clogging.
Winter maintenance will generally include shoveling and chipping of ice in areas where snow and
ice is preventing drainage into chases or inlets. Spring maintenance will include removal of
accumulated sediment or trash from chases, inlets, and ponds, and inspection for areas of sparse
or dead vegetation because of snow storage or plowing operations.
Major maintenance will be scheduled as necessary to repair or replace damaged storm structures
and to revegetate areas of erosion or sparse or dead vegetation. Maintenance to storm ponds
that requires the use of equipment should only be done during summer or fall months when the
facility is dry to avoid rutting or damaging the pond.
Inlets and drain basins should be vacuumed or shoveled out when sediment accumulation in the
sumps has reached or exceeded the lowest pipe invert in the structure.
The Stormtech systems should be inspected and maintained as outlined in the attached manuals.
Inspection & Maintenance Schedule
BMP
Inspection Frequency
A=Annual, M=Monthly, S=After Major
Storm, Q=Quarterly, SA=Semi Annually
Maintenance Frequency
Catch Basin / Storm Inlet SA 1 / year
Storm Chase Q 2-3 / year
Storm Pond Q 3-4 / year
Stormtech System SA See Manual
Table Source: Stormwater Equipment Manufacturers Association