County supports do-it-yourself drainage plans

Small project manual in draft form; public review sought

Clallam County requires every building permit to have a plan for handling storm water at the site. An emerging document, however, would allow homeowners to create the plan themselves rather than paying an engineer to write it for them.

The only catch is the project must be one single-family residence.

"The whole idea is to give people who are building a single home or renovating their existing home the ability to create their own drainage plan," said Carol Creasey, a Clallam County senior planner. "It’s a manual really, for people to do the prep work to get a building permit and to educate them on why it’s necessary to filter storm water, through plain language that is easy to follow."

Storm water is an issue in any place with an impervious surface. Without natural percolation into the soil, storm water often causes flooding, changes in the landscape and water quality problems. Storm water runoff collects oil, chemicals and other substances from impervious surfaces and transports them to groundwater or streams. A drainage plan mitigates against these problems.

"There’s been a major push nationally to clean up the water that runs off and out of new developments, to lessen the impact of building and growth," Creasey said. "While our county has rules in place to ensure these practices are done, we wanted to make it easier for a person to create their own plan rather than paying money for an expert to do something they can do themselves."

The drainage plan manual is in draft form. The county planning commission and permit advisory board reviewed it in late January and early February. Once Creasey adds a few revisions requested by those groups, she will bring it back to them for approval followed by placement on a county commissioner meeting agenda.

"We are getting early input right now," she said. "We want to make sure we have the necessary information in there while still having it accessible to anyone who wants to do a drainage plan on their own."

A drainage plan manages on-site storm water. It includes a drawing of the property, plans for how storm water will be managed and a description of what practices will manage the runoff.

For instance, a homeowner wishing to add on to a home would need a building plan and a drainage plan. The drainage plan could manage runoff from a roof and driveway with a rain garden.

The rain garden provides bioretention – runoff is captured temporarily in a small basin that is lined with native and ornamental plants. The process improves the water’s quality before it percolates to the water table or enters another drainage system, leaving the property.

Different sites and landscapes will dictate different filtration techniques. The manual goes into detail regarding options and "best management practices" for different situations.

The draft plan is available at www.clallam.net under "Current Issues." To comment on the draft plan, e-mail Creasey at ccreasey@co.clallam.wa.us or send a letter to Carol Creasey, senior planner, Department of Community Development, Clallam County, 223 E. Fourth St., Port Angeles, WA 98362.