Millerton nearly full despite drought

Water officials say that's deceptive considering the reservoir's too small.

Published online on Sunday, May. 17, 2009

As California copes with a third year of drought, federal officials are trying to avoid spilling water over the top of Friant Dam at nearly full Millerton Lake.

Millerton probably will fill and possibly spill excess water this week while many major reservoirs remain below 70% of capacity. The reason: Millerton is too small to capture the San Joaquin River's spring runoff even in a relatively dry year, say area water experts.

For days, river water has been funneled into delivery canals to farm-irrigation districts and the city of Fresno. The city is filling flood-control basins where the water can seep into the ground.

"We're very thankful for the chance to recharge the aquifers," said Lon Martin, the city's assistant public utilities director.

It's more than anyone expected in February when federal allotments were forecast at 25% for Fresno and east San Joaquin Valley farmers who buy water from Millerton. A series of late winter storms built the snowpack enough for water officials to become more optimistic.

Now, the U.S. Bureau of Reclamation, owner and operator of Friant Dam, hopes to deliver a 100% supply to the Class I or high-priority customers.

Fresno, Orange Cove and Lindsay are high priority customers. So are many irrigation districts that deliver water to 15,000 farmers on the east side.

Lower priority or Class II farm customers use river water to percolate into the ground to help replenish their wells. They are receiving some water now, but there won't be much more available for them this year, officials said.

Meanwhile, west Valley federal customers, such as Westlands Water District, remain at a 10% supply. The west-siders' Northern California water comes through the Sacramento-San Joaquin River Delta, where drought and legal protections for fish are forcing huge cutbacks in water pumping.

Much of the west-side water comes from Shasta Reservoir on the Sacramento River. The lake is the largest man-made reservoir in California -- nine times the size of Millerton. Shasta is at only 70% of capacity.

Millerton is nearing 100%, but that's a deceptive number because the reservoir is so small, water officials say. The reservoir is about half the size of Pine Flat on the Kings River, which has about the same annual runoff as the San Joaquin.

Pine Flat's capacity is 1 million acre-feet -- each 326,000-gallon acre-foot amounts to a 12- to 18-month supply for an average family. Pine Flat is 61% full with plenty of room for more water. It is not expected to fill completely this year.

But Millerton, with a capacity of 520,000 acre-feet, spills over Friant Dam during spring runoff in many years. The government built it in the 1940s on a site that would not support a larger reservoir, officials said.

Federal officials understood the limitations, but the land was donated and the reservoir was sorely needed at the time.

Fresno Irrigation District, which delivers water in a 245,000-acre area that includes the Fresno-Clovis metropolitan area, is taking water from Millerton. General manager Gary Serrato, whose district is a Class II customer, said his agency this month will get up to 15,000 acre-feet of water.

In February, the district didn't expect any water by now, Serrato said: "We take advantage of every drop of water we can get."

Fresno city officials say residents should not relax conservation efforts. They say years of drought can drastically lower the underground water table, which supplies more than 250 city wells. Fresnans use treated river water and well water.

To conserve, the city this year revised its water rules to prohibit outdoor watering during daytime hours. The revised rules also require the use of a bucket for car-washing, although a hose with a shut-off nozzle can be used for what the rules term a "quick rinse."

About 70% of residential water usage is for outdoor landscaping, said Ann Kloose, spokeswoman for the public utilities department. She recommended residents install drip irrigation and plant drought-tolerant vegetation.

She also said people can cut water usage indoors. "Take shorter showers," she said. "And shut off the water when you're brushing your teeth."