Search
Maintaining Neighborhood Stormwater Facilities
Stormwater
facilities are man-made structures requiring periodic
maintenance to insure that they function properly over time.
The maintenance activity most commonly required is vegetation
management, as excessive plant growth can block inlet and outlet pipes
and reduce the designed holding capacity of a pond. Tree
roots can damage a wet pond's ability to hold water or disturb
the soil layers in a dry pond, which were designed to provide a specific
infiltration rate.
Need to hire a contractor for your stormwater facility management needs?
Check Thurston County's list of stormwater-related contractors to find a company that may be able to help you complete necessary maintenance on privately-owned (neighborhood) stormwater facilities.
Annual Stormwater Facility Inspections
As part of Thurston
County's responsibility to prevent and minimize stormwater pollution,
stormwater facilities must be inspected on an annual basis to ensure
they continue to function properly. Homeowners and private
property owners responsible for the maintenance of a stormwater facility
within Thurston County will receive an inspection form every
year that must be completed by the property manager and/or owner, and
returned to Water Resources staff at:
929 Lakeridge Drive SW
Bldg 4, Room 100
Olympia, WA 98502
Additionally, Thurston County Resource Stewardship staff inspects private and commercial stormwater facilities on an annual basis to ensure they are functioning properly. If any deficiencies are found, a report is sent to the responsible party with details on how to repair the problems(s). Within 30 days of receiving the report, property owners are required to return an enclosed inspection form stating that they either corrected the deficiencies, or plan to correct them at a specified point in the future.
Together, we can work toward ensuring that both private and public stormwater facilities function properly to help prevent flooding in neighborhoods and protect nearby streams from polluted runoff.
Thurston County Water Resources staff recommends maintaining
cattail populations in wet ponds at or below 25%
coverage of the total wet pond area. This is because cattail
coverage over this amount can reduce the designed holding capacity
of a pond and restrict flow in and out of the pond.
To control cattail in a wet pond, individual plants and their entire root system can be pulled out by hand. This method is typically more successful where the plants are less deeply rooted in the looser soil in the middle of a pond than on the edges. If removing cattail by hand is not practicable, cattail can be cut below the water line and all cuttings removed from the area. The rhizomes (roots) of cattail plants that are continuously submerged at least three (3) inches below the water line will eventually die, although multiple cuttings in one year may be necessary to achieve success.
For
small infestations, the entire plant and as much of the root system
as possible should be removed from the area, as remaining roots can
re-sprout. The area should be monitored for several years to
remove seedlings as they sprout. For larger infestations,
mechanical removal with the use of brush cutters, tractor-mounted
mowers, or backhoes should be done when the plants are drought
stressed (July through September) to achieve maximum mortality.
Contact Us
Staff contact: Cathe Linn: (360) 754-4681. E-mail: linnca@co.thurston.wa.us
This page last updated: