Tehachapi News

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Another week, another storm or three for Tehachapi…2008 is on its way to becoming an epic winter for our area and California in general. After a succession of dry years, the storms of winter have returned.

We still need more rain or snow to have a truly wet year, but our annual precipitation averages about 11.75 inches and Golden Hills has already reported 9.45 inches to date.

Though it may be too much to hope for, a wet March would further improve the state’s water outlook. Water managers throughout California are breathing a little easier as reservoirs are replenished and the Sierra Nevada (and Tehachapi!) snowpack accumulates better than it has in years.

Despite the abundant rain and snowfall locally, there have been few problems with flooding. This is due in part to good management by local agencies, especially the Tehachapi-Cummings County Water District, which manages Blackburn and Antelope Canyon Dams south of Highline Road, as well as ID-3, a check dam just north of Highline near Tucker Road.

The check dam is not intended for long term storage but is used for controlled release, to slow run-off during and immediately after a rain so that the streambed doesn’t scour and erode. The water released from ID-3 runs north down along the new Antelope Run walking/bike path, passes under both Highway 202 and Tehachapi Boulevard and then joins Tehachapi Creek near the railroad.

A smaller but also important component of flood control in the Tehachapi area are sumps that are placed near housing tracts and commercial developments to trap stormwater until it can percolate into the ground. These sumps vary in size and shape and resemble small earthen reservoirs with sloping sides. By law they must be fenced to prevent children and others from wandering into them.

Most of the year these sumps are empty and are hardly noticed by the people who live around them or those who drive past the fenced excavation. During dry years they may never have standing water in them.

When heavy rain or snow arrives, however, the sumps fill and reduce catastrophic run-off. They are necessary because development produces a significant area of impermeable surfaces — streets, sidewalks, gutters, driveways, roofs, etc. — and the water that can’t be absorbed by these surfaces has to go somewhere. Sumps help prevent this diverted water from overwhelming flow channels, sewers systems and creekbeds.

The large sump just south of Sherwood Place, between Highline Road and Cherry Lane, was tested to capacity during recent storms. It filled to the rim and only round-the-clock pumping kept stormwater from breaching the sides. Local residents were surprised to see heavy flows of brown run-off flowing down Elm Street even days after the last rain, but this was being pumped out of the Sherwood Place sump.

Once Prestige Homes actually builds houses on the lots that were cleared near Highline Road, storm run-off from that planned housing tract should diminish, but for now the sump has been essential for protecting Sherwood Place homes from flooding damage.

It is interesting how the water never forgets where it’s supposed to go — creekbeds can become grassy and overgrown during successive dry years and minor channels can disappear, but when the storms return the rain quickly re-establishes the old routes.

It reminds me of the exchange in the book and movie Out of Africa, when efforts by the coffee plantation to dam up a stream are overwhelmed by floodwaters. “You can’t keep dis water here,” Issak Dinesen’s native servant informs her matter-of-factly. “Dis water lives in Mombassa,” which was his way of pointing out that the water would naturally flow downstream.

So thus far we’ve been able to enjoy the benefits of a wet winter without suffering much harmful flooding or destructive erosion. Hopefully there’s a few more good storms in our immediate future. . .

Have a good week.