Dream Homes And Muddy Waters Shoreline Building A Big Cause Of Erosion, Stormwater Runoff

Her name is Shireene, not Sherlock. But she’s a pro at tracking the source of dirt running into a lake.

The trail often leads to a home construction site.

Nothing muddies water faster than soil bared for building, says Shireene Hale of the Panhandle Health District.

“Erosion rates can easily go from virtually nothing to 50 or 100 tons per acre per year.”

That murky tonnage makes lakes shallow. It carries phosphorus. Both create ideal conditions for algae and weeds, which aren’t exactly what people hope to see from their picture windows.

Houses can hurt the lake even after they’re built, because they increase runoff. Rain pours off roofs, driveways and other hard surfaces, carrying with it grit from asphalt shingles and oil from the family car.

Houses are a major focus of the lake management plans being written throughout North Idaho. The plans, often written by Hale or modeled after her work, call on counties to strengthen their erosion and stormwater rules.

Rapid population growth is driving the call for change.

“Third world countries are growing at a rate of 2 to 3 percent, which most people think is phenomenal. North Idaho is growing at 7 or 8 percent,” says landscape architect Jon Mueller.

The fastest growth is in the lake-filled, 54-square-miles of Kootenai County, where Mueller is a planning commissioner. He heads a committee of builders, conservationists, planners, environmental officials and other people who are looking at ways to improve Kootenai County’s 4-year-old stormwater ordinance.

One proposal is to divide the county into areas that are at “high risk” or “low risk” for erosion and runoff.

Construction anywhere except on prairie lands can potentially hurt surface water: Dirt runs down roads, into ditches, and can reach lakes from miles away.

But shorelines are always riskiest. The water is near, the soils are often fragile, the terrain steep.

“The cliffs of Hayden Lake are monumentally challenging,” builder Art Elliott says.

Hayden also comes quickly to Hale’s mind when asked to list problem areas in Kootenai County. But erosion is a threat to many Panhandle waterways.

“Ninety-nine percent of the time, we’re building on hillsides,” says architect Jon Sayler. “Everyone built on the easy spots in the 1940s. And on the next easiest spots in the 1950s …”

There’s no sign that lakeshore building will let up. In the last three years, Sayler’s firm alone had 25 clients just on Priest Lake.

Excavation for a new Sayler house is set to begin this week at Kidd Island Bay on Lake Coeur d’Alene. Owners Ronald and Sheila John will pay $4,000 for erosion and stormwater control.

Because it’s within 500 feet of shore, the county requires special precautions such as silt fences and straw bales. Much of the yard will be shaped into swales, or depressions, to capture and filter stormwater.

Kidd Island Bay is filling in with silt, and Ronald John doesn’t begrudge what he calls the county’s impressive rules to safeguard it. He does wince at the cost.

“I guess you’d say I’m distressed and impressed.”

The Johns’ builder is Elliott, who says it’s rare for a buyer to ask about the environmental impacts of their dream home.

Builders and developers are forced to think about water quality. They must get permits. They must tell customers that a stormwater management plan will cost $700 to $1,200.

Plus, builders are accountable if something goes wrong.

June Berquist of the state Division of Environmental Quality is often called in when dirt runs off into a lake.

That’s illegal. Penalties are rare, though.

Developers are usually good about working with environmental officials, according to Berquist.

“They don’t want their reputation to be tarnished with neighbors and people who use the lake.”

Fixing erosion problems can be expensive. So why wouldn’t all builders do it right the first time?

Cost is just one reason. Hassle is another. Silt fences may fall down and need to be fixed. Straw bales may need constant rearranging.

Everyone seems to agree that education is crucial to protecting water quality.

Berquist thinks people should be told about erosion and stormwater control when they buy property.

Construction workers need to know what to do, and why.

That’s a challenge when so many people learn on the job, says builder Kim Riley, who’s keen on water protection and active in industry groups.

“As I travel around the country, I’m appalled at some of the things I see.”

, DataTimes ILLUSTRATION: Color photo

MEMO: This sidebar appeared with the story: DO’S AND DON’TS To protect water quality, Shireene Hale of Panhandle Health District offers these recommendations to people building and maintaining homes near the shore: Make roads and driveways shorter and narrower, to reduce surfaces that can’t absorb stormwater and filter out pollutants. Build multi-story houses, not ranch-style. That reduces the amount of roof surface (which can’t absorb water) and the need to cut into hillsides. Go easy with heavy equipment. Don’t disturb or compact soil more than necessary. Put a layer of washed rock on driveways during construction, to keep vehicles from tracking dirt off-site. Cover exposed soil with weed-free straw. Plant grass and other groundcover quickly. Ninety percent of the erosion here is in the winter and spring; it’s important to have thick vegetation by mid-October. Do without a big lawn. Instead, settle for “a little patch of green.” Turf grass doesn’t absorb as much stormwater as native vegetation. Leave a strip of native vegetation next to the water to stabilize the shoreline, filter out sediment and provide wildlife habitat.