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While filter strips are a simple technology, proper design requires attention to detail because small problems, such as concentration of inflowing runoff or improper grading, can decrease effectiveness and create nuisance soil erosion or ponding of water conditions.

While filter strips are a simple technology, proper design requires attention to detail because small problems, such as concentration of inflowing runoff or improper [[grading]], can decrease effectiveness and create nuisance soil erosion or ponding of water conditions.

*The maximum contributing flow path length across adjacent impervious surfaces must < 25 m.  

*The maximum contributing flow path length across adjacent impervious surfaces must < 25 m.  

*The impervious surfaces draining to a filter strip must have slopes < 3%.

*The impervious surfaces draining to a filter strip must have slopes < 3 %.

*The flow path length across the vegetated filter strip should exceed the maximum flow path length across the impervious surface draining to it.

*The flow path length across the vegetated filter strip should exceed the maximum flow path length across the impervious surface draining to it.

*The filter strip should have a flow path length of ≥ 5 m; however, some pollutant removal benefits are realized ≥ 3 m.

*The filter strip should have a flow path length of ≥ 5 m; however, some pollutant removal benefits are realized ≥ 3 m.