Planning for a Healthy Future: The County General Plan Update
Your voice is needed to promote healthy development policies that will protect Humboldt Bay and other local waterways. Our choices in the General Plan Update will determine whether we protect salmon populations, riparian and wetland resources, and water quality through good land use planning.
Humboldt Baykeeper is a member of the Healthy Humboldt Coalition, working to promote a future that is healthy for us all through a strong General Plan Update. Specifically, we believe the General Plan Update must include specific provisions to:
- Protect riparian and wetlands
- Lead to recovery of imperiled fish populations
- Reduce stormwater pollution
- Restore Threatened and Impaired water bodies
Low Impact Development: New Tools to Improve Water Quality
Low Impact Development (“LID”) reduces environmental impact as compared with conventional development practices by filtering pollutants from stormwater runoff before it flows into creeks and rivers.
Roads, parking areas, rooftops, and lawns turn rainfall into stormwater runoff, carrying polluted stormwater into creeks, sloughs and marshes, eventually flowing into Humboldt Bay and the Pacific Ocean. Motor oil, antifreeze, brake pad dust, fertilizers and pesticides, sediment, pet excrement, and heavy metals from roofing material can have significant impacts on water quality and aquatic life.
Because of the increase in impervious surfaces associated with most development, much more—about 20-30 percent—becomes stormwater runoff. In a typical residential neighborhood, much less rainfall infiltrates the soil to be taken up by plants, and less evaporates into the atmosphere. Runoff quantity can also be a problem, causing erosion and flooding due to unnatural quantities of water rushing across pavement and rooftops.
LID aims to control stormwater runoff close to the source, a new approach to conventional practices of collecting and disposing of stormwater off-site. This is achieved by reducing the amount of stormwater that needs to be treated by reducing the impervious footprint of a site, thereby reducing the amount of runoff. The end results are a reduction in runoff volume, reduced peak flow, and improved water quality.
LID involves site-specific design features that generate less surface runoff, less pollution, less erosion, and less overall damage to lakes, streams, and coastal waters. It also reduces the need for expensive centralized conveyance systems.
Vegetated swales, or “bioswales,” are essentially shallow, sloped, grassy ditches that act as both stormwater conveyance and treatment systems. Pollutant removal in swales is accomplished via filtration through channel and side slope vegetation, infiltration into the channel bottom, and activity of soil microbes. Monitoring of swales has documented significant removals of metals and total suspended solids, though reductions in nutrients such as nitrates and phosphates have been variable.
LID works equally well in new development and redevelopment projects, and can also be used to retrofit existing development. In many jurisdictions, LID principles are mandated in new residential and commercial developments by local ordinance. In Humboldt County, LID tends to be difficult due to existing ordinances and polices governing development. The General Plan Update is a good opportunity to adopt new guidelines to promote the use of LID to protect our creeks, rivers, and coastal waters.
Low Impact Development LINKS
- California Coastal Commission's LID design fact sheet
- City of Eureka's LID Manual
- Orange County Coastkeeper's LID Project
- Natural Resources Defense Council's Stormwater Strategies: LID
- Analysis of Barriers to Low Impact Development in the North Coast Redwood Region, California by Abbey Stockwell - HSU
For Planners and Developers:
- Low Impact Development Center
- Reducing Stormwater Costs through Low Impact Development (LID) Strategies and Practices
- Streetscape improvements and water quality design
- City of Portland’s Sustainable Storm Water Management Program – LID for streets
- City of Santa Rosa's LID Technical Manual
- LID Technical Manual LID Urban Design tools – design software for different BMPs
- Low Impact Development – U.S. Environmental Protection Agency
- Oregon Rain Garden Guide: landscaping for clean water and healthy streams
- Northwest Rain Garden DIY
- 10,000 Rain Gardens
- Rain Garden Design Guide
Laws & Policies:
- CEQA and Low Impact Development Stormwater Design: Preserving Stormwater Quality and Stream Integrity Through CEQA Review
- State Water Board Resolution on LID and Sustainable Water Resources Management
- Resolution of the California Ocean Protection Council Regarding Low Impact Development