The Scoop on Low Impact Development (LID)

Written by: Ange Desaulniers

Last week I had the opportunity to take part in the Washington Association of Landscape Professionals tour of award-winning environmental landscapes in the Puget Sound area. One of the projects featured on the tour was the University of Washington’s Molecular Engineering Building, a project designed to meet a LEED-NC silver rating. One of the many sustainable features of this project was a rain garden used to manage stormwater. N.A.T.S. Nursery supplied several native plant species for this project, and it was wonderful to see how the they were utilized, especially for stormwater management.

What is LID?

University of Washington Molecular Engineering building Rain GardenStormwater management has come to the forefront lately in many cities and communities in the Pacific Northwest, and more and more projects are integrating Low Impact Development (LID) into their planting plans. LID protects water quality and reduces/ slows runoff volume, recharges groundwater reservoirs and aids in restoring habitats. It’s also an important part of stormwater management, particularly for runoff from roads and rooftops that collect pollutants from there impervious surfaces and carry them to local waterways. This is one of the largest sources of pollutants of water in urbanized areas.

How does is it work?

Unlike conventional stormwater management techiques that focus on collecting stormwater and transporting it to a treatment facilty, LID manages stormwater using natural on-site features, site design and runoff distribution such as as rain gardens, bio rention and permeable pavements. Due to new regulations under the federal Clean Water Act, permits administered by the Department of Ecology, all Washington cities and counties will be required to integrate LID into their local development regulations  starting June 30, 2015.

What plants can I use?

Rosa pisocarpaPacific northwest native plants play a significant role in LID in both commercial and residential planting plans. Emergents like Carex obnupta (Slough Sedge), Scirpus microcarpus (Small-fruited Bulrush), Juncus ensifolius (Dagger-leaf Rush), are particularly suited to rain gardens. Border rain gardens with species that are dought-tolerant or adpatable to seasonal changes in soil moisture, like Cornus sericea (Red Twig Dogwood), Physocarpus capitatus (Pacific Ninebark), Amelanchier alnifolia (Western Serviceberry), and Rosa pisocarpa (Clustered Wild Rose). There are many native ferns, perennials and trees that are suited for LID planting plans.

If you’re looking for more information on Low Impact Development and  LID-friendly plants, send me an email.

Here’s a link to the US Environmental Protection Agency’s website.