Will Stanford drain Lake Lag?

In Lake Lagunita sits a drain that’s rumored to have been created by the College within the early days of the lake’s creation. The drain was final operated in 1995 and sure is not going to be used anytime quickly regardless of this winter’s heavy rains, in line with College spokesperson Luisa Rapport.

Rapport wrote that the drain’s lack of operation is “as a result of water is 1681805211 allowed to percolate so as to recharge the groundwater.” 

So who decides when to tug the plug?  In keeping with affiliate professor of civil and environmental engineering David Freyberg Ph.D. ’91, that call is as much as the Stanford Water Division in collaboration with the Campus Biologist Alan Launer ’81 M.S. ’82.

Relating to the drain’s structural properties, Rapport wrote that the system has a valve which controls water circulate via an 8-inch diameter pipe.

The diameter could appear small given the amount of water in Lake Lag however in line with Freyberg, the engineers “don’t need to overwhelm the storm drains” and there actually is “no urgency for drawing [the water level] all the way in which down.”

The College nor Freyberg disclosed the place the valve is situated lest somebody tamper with it. “There’s a valve that’s accessible […] on land” however is locked and “protected in opposition to mischief,” Freyberg stated.

As for the place the drain is situated, in line with Freyberg, round “20 meters out into the reservoir,” you may even see a employees gauge protruding. The drain is true beneath, he says.

Freyberg stated that though there are two spillways to channel extra water away from Lake Lag, they don’t seem to be sufficient to utterly drain the lake. Consequently, he stated, when wanted, the valve is opened and water additionally exits via the drain within the lake.

Freyberg stated that within the drain’s earlier days, the lake was emptied out in order that the College might “mow it.” “In any other case, you’d get a lot of vegetation rising,” Freyberg stated. 

In keeping with Freyberg, if officers determine to open the valve now, it’s to offer an acceptable metamorphosis setting for the California tiger salamander, who could also be imperiled by too excessive of a water degree. In keeping with Freyberg, the salamanders require a dryer setting so they could metamorphose from larvae into juveniles.

Launer, who’s Director of Conservation Planning at Stanford, wrote that when the drain is activated, they’ll “[inevitably] work with the Water Division so as to reduce impacts on wildlife.”

These days, water additionally manages to flee via evaporation and percolation, since “parts of the underside of the reservoir are very leaky,” Freyberg stated. In keeping with him, when the water goes via the drain, it enters the storm sewer and “finally ends up ultimately in rivers and channels round campus,” particularly the San Francisquito Creek.

In keeping with Rapport, pure percolation tends to empty present water by June, however that timeline might change given the 12 months’s rainfall. Though Stanford had an unseasonably wet winter, Rapport wrote that, “This season’s rainfall has not affected the pure percolation of the lake.” Again when the drain utilization was in full swing, having the water degree fall from ‘‘’full’ till ‘dry’ sometimes took about 6 weeks,” Freyberg wrote.

In keeping with Freyberg, there was a plentiful salamander spawn this 12 months, “so there’s a lot of eggs in [Lake Lag],” which is able to information College directors’ choice about working the drain. Nevertheless, for the reason that lake “leaks a lot, [the water level] will most likely go down quick sufficient” that they gained’t want to make use of the drain.

Consequently, “there aren’t any plans to function the drain,” Rapport wrote.