Tropical Rainstorm Expected on Tuesday

A tropical storm heading for Ventura County is expected to drop between half an inch and three inches of rain Tuesday, possibly the last bit of rain on the horizon, meteorologists said Sunday.

The forecast for additional rainfall follows the county’s heaviest rainstorm in five years, a three-day downpour that soaked farmland and provided a slight boost to drought-stricken reservoirs and ground-water basins.

“If we get three more inches of rain, we’ll get a lot more water” into the reservoirs and ground-water recharge pools adjoining the new Freeman Diversion Dam on the Santa Clara River in Saticoy, said Frederick J. Gientke, general manager of United Water Conservation District. “It will be efficient runoff. The ground hasn’t had a chance to dry out.”

Terry Schaeffer, an agricultural meteorologist with the National Weather Service in Santa Paula, said the storm predicted for Tuesday may be preceded by mild rainfall or mist today from a tropical airstream moving from the equatorial region south of Hawaii to the California coast.

“There’s a whole bunch of moisture streaming up from the tropics, and I wouldn’t be surprised to get something pushing out of that,” Schaeffer said. “Our next significant rain should be Tuesday, anywhere from half an inch to three inches.”

He added, “This one may be the last one for a while.”

Grimes Canyon and Balcom Canyon roads between Moorpark and Fillmore remained closed Sunday, impassable because of rock and mudslides caused by last week’s torrential rains.

Runoff from the storms continued to feed the county’s three reservoirs Sunday. Richard Hajas, assistant general manager of Casitas Municipal Water District, said Lake Casitas has risen by nearly three feet Sunday, gaining 4,500 acre-feet since Wednesday morning. An acre-foot is enough to supply two households with water for a year.

Water supply officials are quick to say the storms did little to replenish underground aquifers that have fallen to record depths over the course of the five-year drought. But Hajas acknowledged that the storm provided his district with nearly 20% of the 21,000 acre-feet delivered last year to its customers in the Ojai Valley, western Ventura and the Rincon.

“This is pretty good for us,” said Hajas, whose district declared a water shortage last April. “We were pretty well prepared for no rain this year.”

Although four to six inches fell at most lower elevations, with six to 10 inches in the mountains, Matilija Canyon was drenched by 12.7 inches last week, the highest rainfall recorded in the county. Matilija Dam spilled over the top Friday for the first time in five years, causing the Casitas water district to divert the overflow into Lake Casitas.

Schaeffer said that even with Tuesday’s rainfall, it would take “a couple of rain years of 20 inches or better” to overcome the drought, which has led to mandatory water rationing in many parts of the county.

The Ventura County Government Center averages 16 inches of rainfall a year, but got only five inches last year and 7.47 inches so far in the 1991 rain year, which ends Sept. 30.

Times correspondent Thia Bell contributed to this story.