Irvine Ranch Water District recycles water that goes down the drains and into sewers for reuse in the community, but what happens to the water that flows through gutters and into storm drains?

That water is called urban runoff, caused by any water that flows into storm drains. Inefficient watering of landscape, washing vehicles, or hosing down of sidewalks are contributors. Urban runoff carries with it fertilizers, oils, trash, pet waste, and other contaminants, contributing to ocean pollution when it travels through waterways like the San Diego Creek.

In 1997, IRWD constructed the San Joaquin Marsh, which takes water from San Diego Creek and cycles it though a system of ponds that use plants and soils to naturally clean urban runoff before it flows to the ecologically-sensitive Upper Newport Bay. When the cleaner water returns to the creek, it contains up to 70 percent less nitrates and both sediment and phosphorus have also been reduced.

IRWD has taken the success of the San Joaquin Marsh and expanded the concept to a watershed-wide system of wetlands called the Natural Treatment System. Of the 45 targeted sites, 23 have been built. The NTS sites are anywhere from a quarter-acre to four acres in size and can be viewed from adjacent public areas, such as parks, bike trails and greenbelts.

To find out more, visit our website.