We pulled these five indicators directly from the Toolkit that cities and counties were provided to help update their codes. There are dozens of code updates suggested in the Toolkit. We chose these five simple updates because we felt these updates were straightforward, easy to accomplish, and vital to achieve the larger goal described in the permit “to minimize impervious surfaces, native vegetation loss, and stormwater runoff in all types of development situations.”
As we increase the amount of hard, waterproof surfaces, we create more stormwater. We need to rethink our community footprint. This doesn’t have to mean we lose comfort and enjoyment of our spaces, but we do need to use more landscaping, narrower walkways, and taller buildings.
Key concept recommended by the Toolkit for consideration: Does the code limit maximum impervious surface area for different land use types?
Specifically, we checked to see if a city or county’s development code included hard surface limits for different land use types. We looked for maximum hard surfaces, coverage, lot coverage, hardscapes, and net coverage. This is about more than limiting the square footage of the buildings on a site, but the true footprint – including parking lot, pathways, etc. We wanted to see a city or county provide limits for at least two broad categories of development in this manner. Also, the code must express an actual limit and not be discretionary.
Protecting our lands’ native plants and soils helps water move more slowly by allowing the rain to soak into the earth instead of rushing across the surface and collecting a heavy load of pollution. By building around native plants and caring for the underlying structure of a site, development will be more flood-resistant and support healthy communities in the long term.
Key concept recommended by the Toolkit for consideration: Do land clearing and grading regulations include provisions for minimizing site disturbance and protecting native vegetation?
Specifically, we checked for language that would help protect native vegetation and soils during construction. This could include sediment control measures, fencing requirements around trees and plants, date restrictions (ex. rainy season isn’t a great time to be scraping land), explicit protections for native soils / duff layer / existing infiltration, other disturbance minimization measures, and incorporation of best management practices explicitly from the state stormwater manual. A check mark was not merited if protections only found for critical areas or within the stormwater manual. This had to be more than a consideration but a preference for protection.
Permeable pavement supports vehicles yet allows rainwater to pass through the paved surface into the soil below and reduces how much stormwater we create. Permeable pavements can be used in sidewalks, road shoulders, parking lanes, and other parking areas that do not receive heavy traffic where traditional pavements are needed. Innovative materials are being developed right here in Washington – so we have the local technology to transform our landscape’s surfaces.
Key concept recommended by the Toolkit for consideration: Can permeable pavement be used for parking areas, parking lanes and/or parking spaces? Can permeable pavement be used for sidewalks?
Specifically, we checked for preferences or requirements of permeable pavement for parking and sidewalks guidelines. This could not be just an option but encouraged where feasible. This preference or requirement could not be only required on private property or in specialized zones as well.
Some trees, like cedars and firs, are better suited for our Pacific Northwest environment and do a much better job of helping clean and slow polluted stormwater runoff than other trees. Others, like holly, may not work with the soils, could crowd out the other plants, and might create seasonal maintenance challenges.
Key concept recommended by the Toolkit for consideration: Are specific tree species included in the design guidelines and standards?
Specifically, there must be concrete guidance provided by the city or county. An explicit street tree list was the preferred approach and should be easy to locate as well, whether online or by phone call. This could include a plant list that included trees. However, this could not be limited to a list of banned or noxious trees. Citations to other resources must prove helpful and useful – not a national list and not just a list of descriptors.
Critical areas such as shorelines, wetlands, and other sensitive areas need strips of vegetation (called buffers) to protect their natural systems from the impacts of development and pollution. This includes low-impact development principles, such as retaining native plants which helps to slow and clean polluted stormwater runoff. LID principles and practices have multiple benefits and should be linked throughout the code to recognize these values.
Key concept recommended by the Toolkit for consideration: Can native vegetation associated with LID BMPs be used to meet buffer enhancement requirements?
Specifically, native vegetation must be explicit in describing what is a buffer or what work must be done for buffer enhancement. These requirements must be found in at least one of the critical areas, though should be for all. Often times a city or county may have different codes for wetlands, shorelines, and riparian zones.
If you have questions, contact:
Sydney Harris, Washington Environmental Council | firstname.lastname@example.org
Alyssa Barton, Puget Soundkeeper | email@example.com