The California Drought: Just How Bad is It?
As I write this in early summer, California is suffering through a horrific drought, the effects of which are already having massive impacts on our anadromous fish populations.
Just how bad is it? Well, according to research UC Berkeley paleoclimatologist B. Lynn Ingram conducted using the climactic data stored by old-growth tree rings, this is probably the most parched the state has been since the year 1580.
The past two winters in Northern California have been very dry but the problem has been exacerbated by poor water management, urban sprawl, water deliveries to the central and southern portions of the state and the fact the water agencies are somehow still beholden to water rights granted in the 1800’s.
At press time, Nor Cal rivers were running low and warm and reservoirs were at critically low levels. All of the Central Valley reservoirs (like Shasta, Oroville and Folsom) were well below 50 percent of capacity...and dropping rapidly. By fall, some lake elevations could hit dead pool. Up in the High Sierra, there was an abysmal snow pack so there will be no replenishment until October at the very earliest.
Low lake levels also mean a lack of cold water behind the dams. The unfortunate truth is the rivers will run hot this summer and fall—and that’s not good news for fish.
In fact, during the second week of June conditions were getting so dire that the Nimbus Fish Hatchery on the American River had to evacuate all fish from its raceways because of water temperatures that were forecasted to get up to 78 degrees. Hatchery rainbows were dumped in local lakes and ad-clipped steelhead were released 6 months early so that they’d have a chance to migrate out before they cooked.
The Effects
So, what does all this mean to the salmon and steelhead of Northern California? Well, the immediate future isn’t super rosy—but there are some potential bright spots on the horizon. Here’s a look at the drought’s effects so far—and a glance to the future.
The first ill-effects of the water shortage were apparent late last fall as large areas of salmon redds were left high and dry in the Sacramento, Feather, American and Yuba rivers (and others). In some cases, it was estimated that 40-50 percent of natural spawn was lost.
In the winter, returning adult steelhead found extremely low water in all the rivers, which led to a lot of harvest by opportunistic poachers, particularly on the American until it closed via emergency order.
Then came the out-migration of juvenile wild-spawned chinook in the early spring. Due to the low flows, predator densities were much higher than normal and the tiny fish suffered heavy losses to all sorts of birds and fish.
The fall migration of adult fall-run chinook had yet to occur when I was writing this, but water temperatures in early June were already running 70-72 degrees on many salmon streams and were only going to climb through the summer. The Sacramento River System is forecasted to get a pretty good run of fish this year, but with these unfortunate water conditions, nobody knows for sure what’s going to happen when the kings come home.
One scenario that has crossed my mind is that, unless we get some unseasonably cool weather this summer and a few miracle rainstorms (yeah, right!), we could end up with a thermal barrier situation somewhere on the Sac. In other words, the river could end up being too warm to allow for chinook migration and the fish may just hold somewhere in the salt until conditions improve. Again, just speculation at this point, but I don’t think I’m talking too much out of school here.