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Sonoma County Water Agency eyes strategies to better manage supply

Editor’s note: This is the first in a series of stories about the water supply in the Valley.

With the demand for water increasing and the fluid water supply, the Sonoma County Water Agency and its partners are currently working on a five-year review to revisit and revise its strategies to better manage water and create more effective systems.

The SCWA, which is based in Santa Rosa, was created in 1949 as a special district by the state legislature to provide flood protection and water supply services. In 1995, the water agency was tasked with additional responsibilities of water sanitation and wastewater disposal. The Sonoma County Board of Supervisors acts as the agency’s board of directors, but since the agency was created through state law with a specific mission and powers, it is recognized as its own entity and receives separate funding. The agency sells water in Sonoma and Marin counties and has 4,383 water service connections (meters) and 49 miles of water main. The agency manages six water tanks, two of which it owns, with the storage capacity of 15.5 million gallons. It also has seven wells, with four of them fully active.

But managing the water supply in the Valley is not so simple, SCWA Chief Engineer Jay Jasperse said.

Each variable affects the water supply, Jasperse said, noting the interconnectivity and the difficulty this poses in creating a plan to be prepared for a shortage or a surplus of water.

Jasperse said while the state of water is not certain, Sonoma County “will have water, but (SCWA) wants to be efficient with it.”

The challenge, Jasperse said, is that water management is a constant battle with Mother Nature to create systems and test “how (SCWA’s) systems deal with the variables.” The water agency, therefore, errs on cautious side to prepare for worst-case scenarios. As winter approaches, Jasperse said, he will “assume until proven otherwise that it is going to be dry.”

The water agency has two reservoirs – Lake Sonoma, west of Healdsburg in the northern area of the county, and Lake Mendocino, northeast of Ukiah. Lake Mendocino, which flows into and out of the Russian River, is continuously problematic, Jasperse notes. Right now it is at 30 percent of its capacity because of a dry year.

The City of Sonoma is affected by the problems at Lake Mendocino, Jasperse explained, with the most impact from the depleting reservoir being felt in Ukiah.

On the other hand, Lake Sonoma, which flows into and out of Dry Creek, Jasperse said, has about a three-year carry over and is where the agency gets most of the water for its retail circulation.

The releases from Lake Sonoma were too high in the summer, with the high velocity proving damaging to the surrounding habitats of protected fish (coho and chinook salmon and steelhead) species. The water agency must lower not only the velocity of its flow, but also reduce the amount of times it releases water from it reservoirs by 2023, Jasperse explained. It is currently working on a restoration project in Dry Creek to handle water in a more fish-friendly way. Jasperse said the project aims to create pockets in the waterway with small alcoves where the fish can swim to the side and avoid rapid flows. The key, according to Jasperse, is finding a balance of holding enough water for a good supply and releasing enough water from the reservoirs so that, in the event of a storm, floods are prevented.

While Lake Mendocino is abnormally low, Jasperse is quick to point out that the Russian River is notorious for flooding, citing 32 percent of Federal Emergency Management Agency recurrent flood damage in the county occurs on the Russian River.

Also affecting the Russian River watershed is a diversion tunnel that was created by a hydroelectric turbine installed in 1908 where Lake Pillsbury and the Eel River meet in Potter Valley. A Federal Energy Regulation Commission contract gives Pacific Gas & Electric control of the area and continues to divert water flow from the reservoir.

Another area of concern is the water supply’s vulnerability to natural hazards in the two aquifers. The pipeline transporting water from the Russian River to Sonoma is long, Jasperse said, and it traverses the Rodgers Creek Fault. This fault, which is considered by many to be an extension to the 74-mile Hayward Fault Zone that runs along the hillside in the East Bay, last had an earthquake in the late 17th-century and is due to erupt, according to studies done by the Sonoma State University Geological Department and the United States Geological Survey. The water agency just completed a project to increase the resiliency of the pipeline near the fault.

Groundwater is relatively low; a study the agency conducted in 2000 indicated that the groundwater is decreasing, particularly in the deeper areas, which could be especially destructive to large water consumers like vineyards. Jasperse said the supply of groundwater in Kenwood and Glen Ellen is good, but Sonoma, El Verano and unincorporated areas southeast of Sonoma are concerning. Currently a team of volunteers is monitoring 140 wells in the Valley to understand why groundwater is decreasing and if there are links to the depletion of each source so that a solution can be created.

Because groundwater is low and some areas it is level with or lower than sea level, the salinity of the water is increasing.

“The seas are rising and groundwater is declining, so since water flows, it is natural for the sea water to mix with the groundwater and increase its salinity,” Jasperse said, noting this could make the water not potable and could also cause issues for agricultural producers. Increased water salinity in agricultural areas where producers are pumping from the groundwater supply could kill fragile crops like grapes, he explained.

“Vineyards don’t take a lot of water to grow, but here in the Valley, there are just a lot of vineyards,” Jasperse said. He notes that other regions in California known for producing wine – San Luis Obispo and Paso Robles – have also seen decreases in their groundwater supplies and increases in the salinity.

According to Jasperse, to be prepared, the water agency and its partners are working on immediate solutions to the ever-in-flux water supply and creating long-term goals for how to efficiently and effectively manage water. “The overall strategy is one called Integrated Water Management,” said Dan Takasugi, director of Sonoma’s Department of Public Works and is the city engineer. The city is one of SCWA’s partners. “It combines goals to improve water conservation, groundwater management, recycled water, and conjunctive management of surface and groundwater.”

Takasugi said the biggest issues that affect the city are changing regulations and preparing for drought conditions. He notes the city regularly updates its plan to prepare for threats to the water supply.

“For Sonoma, water management is complex because there are so many diverse stakeholders with vested interests in water issues,” Takasugi said. “Solutions are often very costly, as the projects and policies need to address all stakeholder concerns.”

The water agency is working with the National Drought Information System, National Oceanic and Atmospheric Association, National Weather Forecast and the Scripps Research Institute to forecast weather conditions to better manage the water supply. New technology, Jasperse explained, is helping the water agency better understand the weather systems that affect the Valley and enables scientists and water agency staff to better predict and prepare for changes in water supply. Meteorologists at NDIS, he said, are using technology to predict drought to notify water managers like Jasperse as far in advance as possible so he and his staff can prepare.

Atmospheric rivers are narrow corridors of water in the atmosphere that transport water vapor. Jasperse said these make for 45 percent of all water in the Valley, adding if a storm from one of these rivers hits all at once, the question for him is “What does it mean when it actually hits the ground?”

The USGS has created global climate models and noted that a continued increase in temperature means a higher demand for water. The biggest discovery in these climate models, Jasperse said, is that the weather and thus the water supply are more volatile than in years past, meaning more periods of drought and more periods of floods in short bursts. This unpredictability is especially challenging, he said.

The key, Jasperse said, is adaptation. The water agency and its partners are working on a strategic action plan to meet water demands. The agency aims to balance the amount of surface water and to maximize water recycling and conservation.

One of the biggest endeavors, however, Jasperse said, is managing the 14 groundwater basins in the county, particularly the four largest in Petaluma, Alexander Valley, Sonoma Valley and Santa Rosa. SCWA and the city are planning an Aquifer Storage and Recovery project, or Groundwater Banking project, at Well 6. This project will inject SCWA water into the underground aquifer during the winter season, and extract a portion of that water in the summer season. The problem is, Jasperse explained, with the largest areas for concern about decreasing levels of groundwater in areas outside of the city, the limited funding because there is no municipal fee.

To mitigate water issues such as variables in water supply, increased salinity or decreased groundwater, Takasugi said the city is active in many water conservation measures as described in its 2010 Urban Water Management Plan. Some of these include high-efficiency washer rebates, toilet rebates, cash for grass rebates, and free water audits. As for groundwater, the city is an active participant with other lower Sonoma Valley watershed stakeholders in implementing the Sonoma Valley Groundwater Management Plan. Those stakeholder groups have monthly meetings to discuss activities related to the Groundwater Management Plan.

Both, Jasperse and Takasugi, say Sonomans can aid in resolving water issues by getting educated and being mindful of their water consumption. Takasugi also credits the Sonoma City Council for its attention to water issues that may affect the city, saying “the citizens of Sonoma are fortunate to have a city council

that is very attuned and proactive.”

The city is currently constructing a water intertie project that will address some areas that have low fire flow and will improve water quality. Public Works is also designing the West Napa Street Water System Improvement project.

This project will replace approximately 2,900 feet of the water main along West Napa Street and replace approximately 50 water service lines, Takasugi said, adding the project is expected to start in

spring 2014.

Takasugi said the city will also be updating its water rates over the next year to reflect current demand and supply as the current rates have not been adjusted since 2007.

For details about the water agency and its efforts, visit scwa.ca.gov.