Overview and schedule of general maintenance activities for swales

Overview and schedule of general maintenance activities for swales
First Year of Operation
Activity	Frequency	Time Period	Level of Effort	O&M Benefit^a
Check that there is no ponding	48 hours after event	All year long	1 hour	1
Inspect entire BMP after rainfall	After any event greater than 0.5”	All year long (or during area’s rain season)	2-4 hours	1
Correct earthwork if inlet scouring or unwanted flow paths develop	As needed	All year long	>4 hours	1
Spot reseed bare patches and eroding areas	As needed	First growing season	2-4 hours	3,4,5
Supplemental watering during drier periods, particularly if keeping stormwater offline until plant seedlings are established.	As needed	Dry periods	1-2 hours	3,4,5
Remove any stormwater diversion or barriers once seedlings are established.	Once	When plants are sufficiently established	1-2 hours	1,2,3,4,5
Inspect and remove invasive plants and weeds during plant community establishment	Monthly	First growing season	1-2 hours	5,6
Mowing (dry swales) side slopes and/or grass filter strip to maintain 4-12” of height	Seasonally	As needed (do not interrupt any vegetative establishment)	2-4 hours	1

After First Year of Operation
Activity	Frequency	Time Period	Level of Effort	O&M Benefit^a
Check that there is no ponding	48 hours after event	All year long	1 hour	1
Inspect inlet/outlet structures for structural damage and clogging.	Annually	All year long	1-2 hours	1
Correct earthwork if inlet scouring or unwanted flow paths develop	As needed	All year long	>4 hours	1
Mowing (dry swales) side slopes and/or grass filter to maintain 4-12” of height	Seasonally	All year long	2-4 hours	1
Inspect for trash and debris	Seasonally	All year long	2-4 hours	1,5
Check for evidence of clogging in the pre-treatment device and/or in the main treatment area.	Biannually	In spring and fall	1-2 hours	1
Inspect and remove excess sediment in the pre-treatment device and/or in the main treatment area.	Annually	In spring (post- snowmelt) and fall	4 hours if removal is needed	1
Inspect plant composition and health and replace as needed (maintain >95% vegetative cover)	Biannually	In fall or spring	4 hours if plant replacement is needed	4,5
Prune and weed to maintain appearance and proper vegetative cover	As needed	Growing season	1-2 hours	4,5,6,

After 5+ Years of Operation (non-routine maintenance)
Activity	Frequency	Time Period	Level of Effort per Visit	O&M Benefit^a
After long term operation of the practice, some occasional and infrequent maintenance activities might be required, such as bigger repairs, soil regeneration, or redesign of key elements of the practice.	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
Download an Excel workbook containing this table.