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 certain is not going to be used anytime quickly regardless of this winter’s heavy rains, in response to College spokesperson Luisa Rapport.
Rapport wrote that the drain’s lack of operation is “as a result of water is 1681808797 allowed to percolate in an effort to recharge the groundwater.”
So who decides when to drag the plug? In accordance 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.
Concerning the drain’s structural properties, Rapport wrote that the system has a valve which controls water move by way of an 8-inch diameter pipe.
The diameter could appear small given the quantity of water in Lake Lag however in response to Freyberg, the engineers “don’t wish to overwhelm the storm drains” and there actually is “no urgency for drawing [the water level] all the best way 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 response to Freyberg, round “20 meters out into the reservoir,” you might even see a employees gauge protruding. The drain is correct beneath, he says.
Freyberg stated that though there are two spillways to channel extra water away from Lake Lag, they aren’t sufficient to utterly drain the lake. Because of this, he stated, when wanted, the valve is opened and water additionally exits by way of 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 number of vegetation rising,” Freyberg stated.
In accordance with Freyberg, if officers determine to open the valve now, it’s to offer an acceptable metamorphosis atmosphere for the California tiger salamander, who could also be imperiled by too excessive of a water degree. In accordance with Freyberg, the salamanders require a dryer atmosphere so they might 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 in an effort to decrease impacts on wildlife.”
These days, water additionally manages to flee by way of evaporation and percolation, since “parts of the underside of the reservoir are very leaky,” Freyberg stated. In accordance with him, when the water goes by way of the drain, it enters the storm sewer and “finally ends up finally in rivers and channels round campus,” particularly the San Francisquito Creek.
In accordance with Rapport, pure percolation tends to empty current water by June, however that timeline might change given the yr’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 accordance with Freyberg, there was a plentiful salamander spawn this yr, “so there’s a number of eggs in [Lake Lag],” which can information College directors’ resolution about working the drain. Nonetheless, because the 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.
Because of this, “there aren’t any plans to function the drain,” Rapport wrote.