Land use directly affects how water moves through communities
Land use in urban communities ranges from open space and agriculture to varying levels of development. Developed land often consists of impervious surfaces, such as asphalt and concrete.
When land is paved, water is not able to soak into the ground. Too much water flowing across the hardened landscape can result in flooding and/or erosion. Water that flows over the hardened landscape is lost to the oceans and streams when it is directed into the storm drain systems that lead directly into rivers and oceans.
This untreated water is called urban runoff. Urban runoff, carrying pollutants such as automotive fluids, trash and pesticides, is the biggest source of pollution in our rivers and ocean.
Capturing and Storing Water
Harvesting rainwater offers many benefits for communities. Capturing rainwater not only helps keep our waterways and ocean clean, but helps to replenish our groundwater supply and reduce our dependence on imported water.
Potential strategies for catching and storing water include creating rain gardens, bioswales, bioretention ponds; protecting open space; removing hardscape; and redirecting rainwater that falls on rooftops and parking lots into large tanks (cisterns) where it can be stored for later use.
These various methods function to keep our waterways and ocean clean, and help replenish our groundwater supply and reduce our dependence on imported water. Additionally, sustainable landscaping and irrigation practices can reduce and treat urban runoff while also conserving water.

Resources
Enhancing Urban Runoff
Capture and Use
Prepared by the Office of Water Programs,
California State University, Sacramento
Enhanced Watershed
Management Plan
Prepared by Upper Santa Clara River
Watershed Management Group
Coordinated Integrated
Monitoring Program
Prepared by Upper Santa Clara River
Watershed Management Group