Grassed Swales
Swale maintenance keeps the grass cover dense and vigorous through periodic mowing, occasional spot re-seeding, and weed control. Watering may also be necessary during a drought, particularly in the first few months after establishment. In addition, excessive sediment buildup behind check dams should be removed as necessary.
Vegetative Filter Strips
The maintenance required for a filter strip depends on whether or not natural vegetative succession is allowed to proceed. Maintenance tasks and costs are both sharply reduced for “natural” filter strips. However, corrective maintenance is still needed around the edge of the strip to prevent concentrated flows from forming.
Shorter filter strips must be managed as a lawn or short grass meadow and therefore should be mowed at least two or three times a year to suppress weeds and interrupt natural succession. Periodic spot repairs, watering, and fertilization may be required to maintain a dense, vigorous growth. Accumulated sediments deposited near the top of the strip need to be manually removed over time to keep the original grade.
All filter strips should be inspected on an annual basis. Strips should be examined for damage by foot or vehicle traffic, encroachment, gully erosion, density of vegetation, and evidence of concentrated flows through or around the strip. Extra watering, fertilization, and re-seeding is also usually needed in the first few months and years to make sure the strip becomes adequately established (Schueler, 1987).
