They measured and dug and built for 20 hours a day, six days a week over more than a year, but workers on the Los Vaqueros Reservoir Expansion Project finished the job – ahead of schedule – so that lovers of the outdoors could start re-enjoying the watershed’s treasures.

Last Saturday, Los Vaqueros celebrated its reopening with an array of activities ranging from hikes to up-close encounters with snakes and spiders to demonstrations of Native American crafts and foods. Looming high in the south above the festivities was the new dam, 34 feet taller, widened from 1,000 feet to a quarter-mile and holding a million cubic yards of earth more than the previous structure – all in the service of expanding the reservoir’s capacity from 100,000 acre feet to 160,000.

The reservoir now provides Contra Costa Water District customers not only more water storage, but higher water quality. And factored alongside the human equation are the needs of other Delta dwellers. Those fierce, floppy creatures that provide anglers such exhilarating recreation can’t regulate the salinity of their own habitat. That’s Los Vaqueros’ job.

“We adjust our pumping schedule to protect sensitive fish species such as salmon and smelt,” said CCWD Director of Public Affairs Jennifer Allen. (The Delta smelt, not strictly a sport fish, is an “indicator species” that signifies the Delta’s health.) “And because we’re an off-stream dam, we don’t block any creeks or rivers.”

Fish aficionados appreciate Los Vaqueros’ commitment to their sport of choice. According to CCWD Information Specialist Jim Freschi, the reservoir stocks a thousand pounds of trout every week. And since the expansion project raised the reservoir’s level, forcing the Los Vaqueros Marina to relocate to higher ground, the marina got an upgrade, too. “Boat rentals aren’t available yet,” said Freschi, “and not all the new piers have been installed, but the new marina should open later this summer.”

Fishing is currently limited to the reservoir’s south side, accessible off Vasco Road just north of Livermore.

Back on terra firma, Los Vaqueros' 50-plus miles of trails offer some of the finest scenery – and challenging climbs – in the Bay Area. Saturday’s bash saw naturalists Mike Marchiano and John Mottashed conducting hands-on sessions in the Interpretive Center and among the oaks and reeds of the Kellogg Creek Trail. From seniors to Cub Scouts, hardcore hikers to neophytes in nature, visitors were treated to a taste of the many adventures the watershed affords – and the many educational programs the watershed provides on a regular basis.

The day also featured demonstrations of the ingenuity and intimacy with the land of our Native American predecessors. “The Ohlone women were showing some of their skills using soap root, acorn flour and using dogbane to make rope,” said visitor Eloine Chapman. “I marveled at the ease with which they did it.”

Los Vaqueros Watershed is located south of Brentwood on Walnut Boulevard south of Camino Diablo. For more information on fees, plus the final touches on trails and fishing facilities, visit www.ccwater.com/losvaqueros.