It seems funny that governments have traditionally tried to get people to release as much stormwater runoff as possible from the source into streams, lakes, dams and ultimately the ocean. Nowadays people are a bit more savvy about the value of the rain that is falling on their roofs and gardens. The Seattle PI blog has the following article as an introduction to rainwater harvesting for residents of the area.
The Puget Sound averages about 3 feet of rain per year, most of it falling between November and March. During the summer months we’re lucky if we get a few good downpours and that usually doesn’t even come close to keeping our lawns green. So we’ve naturally started thinking more and more about storing rainwater for when we really need it. These days you’ll see many a house equipped with rainbarrels and more water efficient gardeners are trading in their flora for the less thirsty alternatives. So why not take the next step and create your very own rain garden?
They start with a simple suggestion for houses…
One of the easiest projects to start with is where a downspout empties directly into the lawn and creates a soggy area after every downpour. By removing a small area of lawn, digging in a bed of gravel, setting some riverstones for aesthetics and planting sun and site specific natives a rain garden is born. With houses that have basements a french drain should be added to take the rainwater away from the foundation and then into the rain garden.
Most homes have at least 2 or 3 downspouts that connect directly to the sewer system. With the help of french drains, grassy swales or gutter extensions the rainwater can be directed to one larger rain garden. This rain garden should be placed in a natural or created depression in your lawn. 10,000 Rain Gardens has an easy 1,2,3 on building rain gardens.
Source: Rainwater Harvesting