Rebuilding in Tahoe may affect lake

June 11, 2008 7:38:21 PM PDT
Almost a year after fire destroyed more than 250 houses near Lake Tahoe, there's a frenzy of rebuilding.

Residents are racing to put up new homes and at the same time, nature is struggling to rebuild the fragile environment.

When the Angora Fire swept through South Lake Tahoe last June, the flames never got closer than a couple of miles to the lake itself.

But in the Tahoe basin, everything that happens to the environment is tied to the future of the lake.

Every river, every stream and storm drain eventually feeds in or out of Lake Tahoe, and at the same time, they feed the economy.

"From an economic standpoint, the lake is our big ticket item, and if there is anything that happens in terms of degradation of clarity, we are all in trouble economically," said El Dorado County Supervisor Norma Santiago.

The fire burned 250 homes. Rebuilding is happening at a record pace. Great for residents, but it could be a big threat to the lake.

Julie Kolowitch is an inspector for the Tahoe Regional Planning Agency.

"There is a huge area of construction. Normally when we are inspecting properties, there may be one in a neighborhood. Here we have a hundred-maybe. And there's contractors from all over California, from out of town, who aren't necessarily familiar with all the rules," said Kolowitch.

Those rules are to protect Lake Tahoe from dust and dirt at construction sites.

"You think about it, if a thunderstorm came through and it started raining really hard, this dirt is just going straight down the street, right into the drain and basically right into the lake," said Kolowitch.

Tahoe is world famous for its clarity. But that clarity has been declining in the last 30 years. One of the biggest problems is "suspended particles" -- tiny bits of dirt that build up over time and cloud the water.

The soil can also contain nitrogen and phosphorous that encourages unwanted algae in the lake.

Julie's job is to make sure every construction site is keeping dirt and sediment contained.

"The fencing looks good. You can tell because it's pretty firm in the ground," said Kolowitch.

Most homeowners are cooperative, but a little nervous when she shows up.

"So you are not going to write us up right now?," said a Lake Tahoe homeowner.

While Julie's inspecting home sites, the Forest Service is watching over the rest of the 3,000 acres that burned.

"What we're trying to do through restoration is to give an area the sort of kick start it needs to set up a certain range of conditions so the natural processes can take over," said Rex Norman from the U.S. Forest Service.

In some areas, rice straw was used to prevent erosion. ABC7 News was here last summer when crews began spreading straw in the lower elevations.

Now, ten months later, it appears it did the job.

"You see there are just little bits of it left. Underneath it, you can see some of the blackened areas. This area was all burned over - alright - it was completely burned. So all the green that you see in there is new vegetation that's come in," said Norman.

On higher slopes, planes dropped "hydromulch" -- a biodegradable mix of paper cellulose and a binding material that hardens over the hillside.

The hydromulch is still in place, and native plants are poking through.

"It's the first time we've used it here in the basin after a fire and its done a very good job of stabilizing the soils. We are also lucky we didn't have a big spring runoff this year," said Norman.

The Forest Service says tests on streams show very little sediment from erosion in the fire area. They're also measuring the fire's effect on the soil itself. Fire vapors create a sort of varnish that can cause soil to repel water.

"We don't see any bubbles coming up so the water's not flowing through this soil very rapidly at all," said Tim from the Forest Service.

This kind of testing will help with planning for the future restoration of the forest.

Perhaps the biggest question mark is still: what to do with the trees - both "dead" ones, that many consider an eyesore - and "live" ones, that are too dense and creating an unhealthy forest.

"There will be some be some tree-cutting, there will be some reforestation. But will it be done on a widespread basis? Probably not. We're going to look at each area for its own eco-system needs," said Norman.

Last month, the governors of California and Nevada declared every county around Lake Tahoe a disaster area - because of the threat of future fires.

Some thinning of the forest has already started. The challenge is to do it without creating erosion that could damage the lake.


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