Low-Impact Development
Low-impact Development: Protecting our waters as we grow
The Puget Sound lowlands are beautiful and life here has many rewards. So it’s not surprising that more people than ever want to call the Puget Sound region home. By 2025, an additional 1.4 million people are expected to move here. As we grow, we replace forests and prairies with rooftops and pavement—increasing the stormwater that runs off and harms local waterways and Puget Sound.
Tips for Using this Guide
ü Pressed for time? You don’t have to read this guidebook cover to cover. But you might find it useful to at least skim through all the sections to see what LID ideas might work for you. Some ideas may apply more to new construction or home additions.
ü How much will it cost? Wherever possible, this guide will provide cost information. Costs can vary depending on factors such as your location, site access, time of year, and how much you do yourself vs. hiring professionals.
ü How hard is it? You can do many LID strategies yourself, for very little cost and sometimes savings! Other ideas may require you to seek expert advice. Still others might require you to hire a professional. This guide provides tips in each section so you’ll know when to seek help and where to go for assistance.
ü New construction : If you’re building new, look out for the blue text for extra suggestions.
Fortunately, low-impact development (LID) is catching on as a way to grow smarter and reduce the problem of stormwater runoff. This guidebook is filled with lots of useful ideas to help protect and conserve the water you depend on, while also beautifying your home and yard.
What’s the problem with stormwater?
Around your house, you might find stormwater a problem when heavy storms cause flooding around your foundation or in your basement, and you have puddles on your walkways and driveway.
But even if you don’t see it, stormwater is a problem in your community. Stormwater—and the pollution it carries—is causing problems in our region. Here are some of the consequences:
q Several species of Northwest salmon face the threat of extinction.
q Numerous beaches on Puget Sound are too polluted to harvest shellfish.
q Pollutants—such as motor oil, yard chemicals, and pet wastes—get picked up by the stormwater and end up in our local waterways, threatening human health and wildlife.
q English sole are developing liver disease in association with contaminated runoff from roadways.
q Winter rains flood streams, threatening buildings and eroding farmland.
q During summer and fall, many streams lack sufficient water to support fish because rains have rushed off the landscape instead of recharging groundwater aquifers.
Looking for LID
If you’re in the market for a new house, consider a home designed with LID in mind. In addition to seeking features described in this guide, look for:
- Sites with mature vegetation.
- Houses with a smaller footprint.
- Developments whose common spaces contain lots of trees and shrubs.
- Location offers you more sustainable transportation choices, such as: short walk to a bus stop; sidewalks and bike lanes to encourage less driving to work and errands; close to markets, workplace, and other places you go often. The less we all drive, the fewer roads will be built or widened—helping us preserve our communities and keeping waterways cleaner!
Our typical ways of developing land aren’t working. When we clear and grade the land to make room for more houses or shopping centers, we replace natural systems that have processed our heavy rainstorms for eons with engineered systems that aren’t as effective as Mother Nature.
In an undeveloped system, native soils and many layers of plants slow down and absorb our heavy