Controlling Runoff

Bioswale for collection of runoff, courtesy Aaron Volkening

Controlling runoff from your lawn is important – high levels of runoff can damage the local ecosystem and water supply by sweeping pollutants, fertilizers, and chemicals into storm drains. There are numerous different ways you can control, divert, or absorb rain water before it turns in to toxic, pollutant-carrying runoff and enters the storm system.

Bioswales

Bioswales are generally large areas of plantings that sit around the edge of properties. They use sedges, rushes, and other water-loving plants at the bottom of a slope, just above a drainage ditch. These plants help to slow down water coming down the slope, and allows for petroleum, fertilizer, and other pollutants to be filtered out and settled down before the water ends up in a drain or creek. Low-growing grasses, native shrubs, and trees planted along the slope also help to slow down fast-moving runoff so that pollutants can settle out.

Rain Gardens

Similar to bioswales, rain gardens are meant to keep pollutants and runoff from leaving the property. Unlike bioswales, rain gardens are often features around building, paths, and parking lots, not at the edge of the property. Rain gardens provide a place near impervious surfaces for rain water to collect, settle, and soak in to the land instead of running off into the storm drains. Also unlike bioswales, where the goal is simply to slow down the rush of water and collect pollutants, rain gardens aim to stop the runoff entirely

Permeable Pavement

A somewhat recent development in regards to dealing with runoff, permeable pavement allows for some of the water that would otherwise flow in a stream to seep down through the pavement and into the ground beneath. This water wold otherwise continue to flow and carry the runoff and pollutants to the creek system or drain system. There non-permeable pavement effectively seals off the ground beneath, permeable allows for this ground to still be used to soak up rainwater while being used as a paved path or surface.

Maintaining your Runoff Control

All three of these are great ways to control runoff, but all three also require regular maintenance to be effective. Weeds and grasses will still need to be controlled in the bioswale, or it will turn into a weed patch. All three need to be checked for and cleared of large pieces of debris – this can reduce the capacity of rain gardens, and hurt the drainage capabilities of all of them. More importantly, regular maintenance during the first few years of growth and development will help the bioswale or rain garden to thrive. Failure to maintain it may require a full rebuilding or replanting.

Using one of these methods of controlling runoff is a great idea, and it will help out your neighborhood. What’s more, it is likely that some of these measures may be required by communities in the future, so it’s certainly a good idea to get a jump on things. Bioswales and rain gardens are fairly simple and easy features that can be designed and installed by anyone with even a slight knowledge of landscaping, so many folks can make these on their own.