The district has proposed an 18-month, $26 million dollar project to replace a deteriorating outlet pipe under the James J. Lenihan Dam. The current pipe, which empties water from Lexington into Los Gatos Creek, was installed in 1952. Since 1989, numerous bulges have been discovered and repaired along the pipe.

Water district spokesman Mike Di Marco said that the pipe is safe, but that the state agency regulating dams has placed restrictions on its use. A new pipe would allow the reservoir to be drained more quickly in the event of heavy rain, an earthquake or other situation that would require doing so. The pipe is also used to release water during dry months and replenish the groundwater basin.

A public hearing will be held Sept. 9 at 7 p.m. in the Los Gatos Neighborhood Center at 208 E. Main St. to hear comments on a preliminary environmental impact report.

According to the report, there are a number of potentially significant impacts, but most can be mitigated through careful planning and work practices. Some, though, will be unavoidable.

The first phase of the project would consist of tunneling through St. Joseph's Hill east of the dam. The second phase would require the reservoir to be lowered to a volume of about 13 million gallons—significantly lower than its 6.4-billion-gallon capacity.

The volume reduction is the cause of two unavoidable concerns. One is that the Los Gatos Rowing Club and other recreational boaters would not be able to use the facility during the period. The other is that the water temperature could rise as much as five degrees in the reservoir and the upper sections of Los Gatos Creek. This could have a negative impact on rainbow trout living in the creek.

"We have a staff of fisheries biologists," DiMarco said. "They'll be monitoring that on a regular basis."

He said that if the drainage occurs when planned, the fish would probably not be in the areas that would warm up, but that if temperatures rise and fish are hanging around, "fish-rescue operations" are available to transport the trout to a safer habitat.

"We will spend a considerable amount of time and effort making sure the fish are safe," he said.

The rowers, though, are on their own. Santa Clara County Parks and Recreation Department spokeswoman Tamara Clark-Shear said other county reservoirs allowing nonpowered boating could serve as temporary replacements. Stevens Creek Reservoir in Cupertino is the closest such facility to Los Gatos.

Los Gatos Rowing Club president Shirley Reekie said that if water levels are too low for boaters, it would be quite a "pain in the neck" to relocate the operations of more than 125 high school students and 100 adults who use the reservoir. But she said she understood the need for the construction work, and appreciated the water district notifying the club so far in advance of work.

"Ultimately it looks like if this gets fixed, we should benefit as well," Reekie said. "I guess you have to put up with one year of complete misery so that you have a better water level overall."

All recreational trails in the area are expected to remain open during the construction, though a portion of the Los Gatos Creek Trail would be temporarily rerouted.

The water district will present its board of directors with a final environmental impact report, incorporating any concerns raised by members of the public, next spring. DiMarco said the project could start as soon as late spring or early summer of 2006.

Copies of the draft environmental impact report and an engineer's report are available at the Los Gatos Community Library and online at www.valleywater.org.