Overview and schedule of general maintenance activities for wetlands Overview and schedule of general maintenance activities for wetlands

Overview and schedule of general maintenance activities for wetlands

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First Year of Operation
Activity	Frequency	Time Period	Level of Effort	O&M Benefita
Check that there is no ponding in the pre-treatment device.	At least twice after storm events > 0.5 inches	Within the first 6 months	1-2 hours	1
Check for evidence of clogging in the pre-treatment device and/or in any conveyance structures	At least twice after storm events > 0.5 inches	Within the first 6 months	1-2 hours	1
Maintain proper water level for establishing vegetation (may require supplemental source)	1/week initially	During first 2 months	1-2 hours	2,3,4,5,6
	As needed	First growing season	1-2 hours
Remove any stormwater diversion or barriers once seedlings are established.	Once	When plants are sufficiently established	1-2 hours	1,2,3,4,5
Install protective barriers (e.g. chicken wire) to protect growing vegetation from wildlife	As needed	First growing season	8 hours	1,2,3,5
Check for signs of burrowing animals and incorporate gravel or rock in problem areas to discourage burrowing.	As needed	First growing season	1-2 hours	5
Check that water is moving as planned through the wetland. Identify and fix any stagnant zones.	As needed	During first 2 months	4 hours	1
Mow dikes frequently to establish deep rooted ground cover	Biweekly or as needed	First growing season		3,4
Remove and replace dead plants	As needed	First growing season	2-4 hours	2,3,4,5,6
Spot reseeding of bare patches and eroding areas	As needed	First growing season	2-4 hours	1,2,3,4,5,6
After First Year of Operation
Activity	Frequency	Time Period	Level of Effort per Visit	O&M Benefita
Check that there is no ponding in the pre-treatment device	Biannually	Any time when ground is not frozen	1-2 hours	1
Check for evidence of clogging in the pre-treatment device and/or in any conveyance structures.	Biannually	In spring and fall	1-2 hours	1
Remove trash and debris from the pre-treatment device and/or in the main treatment area.	Monthly	All year long	1-2 hours	1,5
Inspect for and remove excess sediment in the pre-treatment device and/or in the main treatment area.	Monthly	All year long	4 hours if removal is needed	1
Check and repair eroded areas	Annually	In fall or spring when vegetation has died down	4 hours if repairs are needed	1,2,3,4,5
Weed and remove invasive plantsb	Twice during growing season	During growing season	1-2 hours	2,3,4,5
Inspect plant composition and health and replace as needed to maintain >50% coverage.	Biannually	In fall or spring	4-8 hours, more if plant replacement is needed	2,3,4,5,6
Remove woody vegetation on or near embankments, forebays, spillways, and outlets	Annually	In fall or spring	4 hours	1,2,3,4,5,6
Check for signs of burrowing animals and incorporate gravel or rock in problem areas to discourage burrowing.	As needed	During growing season	1-2 hours	1,2,5
Inspect for and repair broken inlets, pipes, or other water control structures	Biannually	After high flows and ice breakup	2 hours, more if repairs are needed	1
Mow dikes and remove any shrubs or trees growing on dikes	As needed	During growing season	1-2 hours	1,5
Monitor operating range of water level	Daily (collect data continuously, use information to diagnose issues)	Any time	1-2 hours	1,2,4,6
Check that water is moving as planned through the wetland. Identify and fix any stagnant zones	Annually	During growing season	4 hours	1,2,3,4,5
Inspect sediment accumulation in forebay and treatment areas. Remove if hydrology is impacted or if less than 50% of forebay capacity remains.	Annually	Fall	2 hours	1,4,6
Harvest wetland plants	Once every 2-3 years	After growing season	4-8 hours	1,4,5,6
Remove sediment from forebay	Once every 2-7 years, or when less than 50% forebay capacity remains	As needed	Varies	1,4,5,6
After 5+ Years of Operation (non-routine maintenance)
Activity	Frequency	Time Period	Level of Effort per Visit	O&M Benefita
Remote inspection of all conveyance structures (e.g. pipes, underdrains, etc.)	Every 10 years	Any time	Varies	1
After long term operation of the practice, some occasional and infrequent maintenance activities might be required, such as bigger repairs or redesign of key elements of the practice. Replacement of concrete components (e.g. pipes, risers, may be required after 25-50 years.	As needed	As needed	Could be significant depending on the activity	1,2,3,4,5,6
aKey to Maintenance Benefits: Proper stormwater flow and infiltration Creation and maintenance of wildlife habitat Creation and maintenance of pollinator habitat Nutrient cycling and storage Aesthetics and public enjoyment Carbon sequestration bRemove invasive species immediately and replace vegetation as needed. As a general rule, control of undesirable invasive species (e.g., cattail and Phragmites) should commence when their coverage exceeds more than 15% of a wetland cell area. Although the application of herbicides is not recommended, some types, such as Glyphosate, have been used to control cattails with some success. Extended periods of dewatering may also work, since early manual removal provides only short -term relief from invasive species.