TRPA changing approach regarding individual BMPs

By Kathryn Reed

STATELINE – A communal approach to BMPs may save individual property owners money and angst, while also keeping more sediment from reaching Lake Tahoe.

While the Tahoe Regional Planning Agency is not doing away with best management practices, it is headed toward being less focused on what individuals (those 43,000 parcels) are doing and more focused on communitywide efforts.

Through the total maximum daily load protocols mandated by the Lahontan Regional Water Quality Control Board on the California side of the lake and Nevada Department of Environmental Protection in the Silver State, TRPA in part will be using the data they collect to help measure the volume of sediment reaching the lake.

John Hester, who is overseeing the Regional Plan update for TRPA, said staff is proposing being less focused on monitoring individual projects and instead looking at larger areas, including subwatersheds. He said the idea is to get away from a one-size fits all approach.

During a multi-hour presentation to the TRPA Governing Board last week, reps from both states and the TRPA outlined how using the total maximum daily load will be incorporated into the Regional Plan update. That update is expected to be voted on in December.

But it was stressed that the TMDL is not the sole mechanism for achieving lake clarity.

“There is some sense that TMDL is all there is,” Joanne Marchetta, TRPA executive director, said. She said that’s not accurate. “The whole system is much larger than that.”

She said the TMDL is one component of the stormwater management system, which in itself is just part of the bigger picture. After all, particles floating in the air also contribute to water quality issues.

“Fifteen percent of fine sediment is from atmospheric deposition,” Bob Larson with Lahontan told the TRPA board. “But we don’t know exactly where it is from.”

He said it is most likely dust from paved and unpaved roads. While past theories put the blame on the Sacramento Valley and Gobi Desert for polluting Lake Tahoe, Larson said that is not the case.

Road improvements – including better street sweepers, along with improved public transportation are ways the road dust could be decreased.

Marchetta went through the evolution of water quality programs in the basin starting in the 1970s.

She admitted the introduction of parcel-by-parcel best management practices “was not driven by science. It was driven by policy.”

The theory was every drop of water needed to stay on the property it landed on.

BMPs have cost homeowners and businesses a tremendous amount of money in the last couple decades with no measurement as to whether they did any good. It meant redoing driveways, putting in drip lines so the runoff from roofs didn’t cause erosion, and covering bare soil.

“Simple erosion control practices will continue to be required around roof drip lines and to stabilize bare soil, but area-wide solutions are being recommended to help property owners with things like their driveways,” Kristi Boosman, spokeswoman for TRPA, told Lake Tahoe News after the meeting. “The draft Regional Plan proposes to coordinate TRPA’s BMP implementation efforts with local jurisdictions so that limited resources are focused in the areas that achieve the greatest pollutant load reduction. These areas would be determined by load reduction plans and Lake Clarity Crediting Program load reduction strategies local jurisdictions have to prepare as part of the TMDL.”

Besides stormwater concerns, water quality is impacted by watershed management, invasive species, how threatened-endangered-sensitive species are handled, and whether it was a dry or wet winter.

Through the TMDL program, the five counties, one city, U.S. Forest Service, and two state transportation departments collectively are tasked with reducing fine sediment particles reaching the lake by 10 percent in the next five years and by 33 percent in 15 years.

Larson said if a switch were flipped today that stopped the sediment from reaching Lake Tahoe, it is estimated it would take five years for the lake to respond – to be at the desired clarity level of water officials.