Low-Impact Development (LID)
As more impervious surfaces – roads, parking lots and buildings – are built in a watershed, more runoff is produced that is contaminated with oil, grease, metals, trash, bacteria, and other pollutants. This polluted runoff enters our waterways and contributes to beach closures, depressed fish populations and harmful algal blooms, all of which hurt our economy directly or indirectly. Increased flow may cause stream beds and banks to erode, damaging or eliminating stream habitat and carrying sediment downstream. Low-Impact Development (LID) is a set of stormwater management strategies that reduces impervious surfaces, treats runoff, controls runoff peaks and durations, and thereby helps protect water quality and stream resource integrity.
LID works. Its implementation is being fast-tracked by the federal government (most notably, the Department of Defense) and in many states. In California, the State and Regional Water Boards are already incorporating LID into their Statewide Construction and Municipal NPDES permit requirements. In early January 2008, the State Board released a policy analysis that examines the State’s primary mechanisms of regulating stormwater runoff and considers how LID approaches could be used for compliance purposes. Many local communities in California are also adopting LID requirements and practices.
LID can also benefit the business community. In December 2007, the U.S. Environmental Protection Agency released a new report entitled “Reducing Stormwater Costs through Low Impact Development (LID) Strategies and Practices.” The report contains 17 case studies from across North America that show the economic viability of LID practices. The report demonstrates that, in almost all cases, LID can reduce project costs while improving environmental performance. Total capital savings ranged from 15 to 80 percent, with one exception in which LID project costs were higher than conventional stormwater management costs. As LID practices become more common, it is likely that they will become cheaper to use.
Promoting LID in California was included in the 2008 OPC program priorities and at the February 2008 meeting, a report was presented to the Council exploring state and local policies that encourage or require LID. At the May 15, 2008 meeting, the OPC adopted a resolution regarding LID. As stated in the resolution, the OPC found LID to be a practicable and superior approach to minimizing and mitigating increases in runoff and runoff pollutants due to land development. Further, LID is cost-effective, has many ancillary benefits, and in most cases can be executed at lower cost than conventional drainage systems. Three topics were identified for action by the OPC to promote LID: state leadership, state regulatory action, and incentives, technical support and research. The resolution also included various items the OPC could consider funding to promote LID. Since the adoption of the resolution, the OPC has engaged with the Natural Resources Agency, California EPA, the Office of Planning and Research, Caltrans, the Building Standards Commission and the Department of Water Resources to encourage incorporation of the principles of LID in projects and standards. Standards for regulatory actions are also being developed by the State Water Board with assistance from the California Coastal Commission and the OPC.
The OPC awarded funds to Tetra Tech to examine the state and local policies that encourage or require the use of LID. The final report, “State and Local Policies Encouraging or Requiring Low Impact Development in California” (January 2008 ) serves as a clearinghouse for LID activities throughout the state, although as LID becomes more widespread, newer projects are not described.
As called for in the OPC Resolution, the Office of Planning and Research and OPC staff are working together to produce a technical advisory regarding the use of LID. The advisory was completed in summer 2009.
Other portions of the OPC Resolution are being enacted with the relevant agencies.