Tag: department of water resources

Posted on

Portrait of a Drought: Lake Oroville

lakeoroville040514.jpg

The further adventures of a California reservoir. A year and a week ago — late March 2013 — Kate and I camped in the very nice Loafer Creek campground at Lake Oroville State Recreation Area. The lake, the main reservoir for the State Water Project and the second largest California reservoir after Lake Shasta, was about 85 percent full at the time. If you were following the vagaries of the state’s water season, you might have been a little troubled by the fact the 2012-13 rains had virtually disappeared after the turn of the new year. What wasn’t apparent during the first visit up there was that the rains wouldn’t return in the fall, either, and that the lake would fall to just one-third full by January — low in any season, but especially alarming in that the reservoir levels here and virtually everywhere else across the state continued to decline at a time when they’d usually be filling up with runoff from winter storms.

I drove up to Lake Oroville on January 18, which happened to mark the lake’s low point during the current water year (July 1, 2013-June 30, 2014). The difference in the lake’s appearance was dramatic — see the slideshow below. But when seasonal rains finally returned in early February, the lake began to rise. One way of measuring lake level is the height of the lake surface above sea level. When full, Lake Oroville’s surface is 900 feet above sea level. When Kate and I visited in March 2013, the surface level was 860 feet; when I went back in January, it stood at 701 feet according to the numbers from the state Department of Water Resources. The same source shows the lake at 759 feet now and rising.

Yesterday, Thom and I drove up to Oroville to take a look and take a new set of pictures to show the change since January (they’re incorporated into the slideshow). My impressions:

I suppose this is a “glass half-full/half-empty” exercise on a grand scale, especially since the lake is at almost exactly 50 percent of its total capacity right now. On one hand the lake is up almost 60 feet from the last time I saw it and has added about 40 percent to its storage — it’s added about 500,000 acre-feet since January, enough water for about 1 million California households. More water is coming, too: Even though the forecast for the next couple of weeks and beyond looks pretty dry, and even though we’re nearing the tail end of the rainy season, the snowpack will start too melt and run down the branches of the Feather River that flow into the lake.

The conventional wisdom is that half of the state’s stored water is captured in the Sierra snows that wind up in streams, rivers and reservoirs. One slice of Lake Oroville history shows how dramatic an impact the snowpack can have:

A drier-than-normal water year in 2008-09 reduced the reservoir’s storage to a shade more than 1 million acre-feet, less than 30 percent of capacity, and lowered the surface to 665 feet above sea level by early January 2009; that’s about 20 percent less water and about 45 feet lower than the level we saw this past January. Then storms began arriving and began building the northern Sierra snowpack. The water content of the snow in the Feather River drainage reached about 130 percent of normal by early April 2010, and the lake had come up to virtually the same level as it is this weekend. The reservoir, which had reached its lowest point on January 11, kept rising through June 29, when it reached its high point of about 2.7 million acre-feet and elevation of 843 feet above sea level. That’s a rise of 178 feet in less than six months.

So that’s the glass half-full. It’s normal for our reservoirs to rise and fall, often dramatically (and no, I’m not addressing here the impact of how the reservoirs are operated — how much water is released, when, and why).

Here’s the empty half of the glass for Lake Oroville: This year, the Department of Water Resources estimates that the water content in the thin layer of snow in the Feather River watershed’s high country is just 13 percent of average for this time of year. Thirteen percent. So, we’re not going to see any late season rise in the lake. More likely, we’ll see a scenario more like the one that unfolded in 2007-08, when two drier-than-normal years left the lake at close to the same level we see today — 753 feet. The watershed’s snowpack was lower than normal, and although runoff gave the lake a boost, it topped out at just 760 feet and 50 percent capacity in late May. That dry rain year was followed by another, and in February 2009, the state declared a drought emergency.

None of this is meant to make a single reservoir, even a big one like Lake Oroville, seem more important than it really is. But reservoirs are important to making it possible for 38 million people to live, and for a rich agricultural industry to thrive,in a place where it typically doesn’t rain much for six months of the year. And Lake Oroville’s water storage happens to mirror what’s happening with the state’s water supply picture as a whole at the moment: The Department of Water Resources’ daily summary of 44 key reservoirs shows them collectively at 64.4 percent of average for today’s date. Lake Oroville is at 65 percent.

Here’s the revised slideshow:

Posted on

Hey, Rainmaker

A dry summer, and then comes the fall
Which I depend on most of all.
Hey rainmaker can you hear the call?
Please let these crops grow tall.

—The Band, “King Harvest”

We had some rain overnight–just enough to keep the dust down, if there had been any dust (we did have plenty of crap in the air, though: a miasma of car exhaust, smoke, and other metropolitan exhalations that led the regional air district to ban wood fires for four days in a row). The “storm” total in San Francisco for the rain that started falling last night is .04 of an inch–four-hundredths–and according to the National Weather Service is the first rain since we got .21 of an inch on Thanksgiving.

Meantime, continuing my claim to be the first in my neighborhood to express precipitation anxiety this year, the state Department of Water Resources and its California Data Exchange Center are out with their latest summary of hydrologic conditions for the state. Here’s my summary of their summary: November 2010 was wet, November 2011 was dry. Or in the summary’s own machete-proof prose:

On November 30, the Northern Sierra 8-Station Precipitation Index Water Year total was 6.5 inches, which is about 70 percent of the seasonal average to date and 13 percent of an average water year (50.0 inches). During November, the total precipitation for the 8-Stations was 2.6 inches, which is about 41 percent of the monthly average. Last year on November 30, the seasonal total for the 8-Stations was 15.5 inches, or about 167 percent of average for the date. On November 30, the San Joaquin 5-Station Precipitation Index Water Year total was 4.0 inches, which is about 59 percent of the seasonal average to date and 10 percent of an average water year (40.8 inches). During November, the total precipitation for the 5-Stations was 1.5 inches, or about 32 percent of the monthly average. Last year on November 30, the seasonal total for the 5-Stations to date was 14.4 inches, or about 212 percent of average for the date.

Of course, one or two good drenchings will make all this early-season anxiousness go away.

Related:
It’s December. Do You Know Where Your Rain Is?
KQED: California Reservoir Watch

Posted on

California Water: Face of the Drought

It’s California Water Saturday in these parts. Let’s see if I can keep it simple:

Continued wet weather means most of the state’s reservoirs are filling up. But if your definition of drought means all reservoirs brim-full, no, we’re not out of the woods yet. (My KQED Radio News colleague Amy Standen just finished a story that will air Monday: “Is the Drought Over?” (I have a starring role in her accompanying blog post.) Another take on our drought status comes from the U.S. Drought Monitor. Over the last couple of weeks, this report has shown a dramatic contraction of the area of the state affected by drought.

The face of the drought: At the end of January, the state Department of Water Resources issued its latest drought update (18-page PDF). The most interesting aspect of the document is the way it adopts the Westlands Water District as a proxy for the drought’s impact on agriculture throughout the state. It’s not a subtle touch, either: the front and back covers of the drought report contain dramatic photographs, courtesy of Westlands, of dead orchards. We’re to understand from the context that drought has killed these productive groves. Inside the report, there’s a writeup on Westlands, complete with a table on page 12 showing the reduction in planted acreage since 2006–a little misleading to use as an index year since it was a decidedly wet year when no one had to worry about water supplies. The table does show that virtually all field, seed, and truck crops have experienced dramatic reductions since ’06 (exception: wheat, for which acreage grew by 53.4 percent, and garbanzo beans, which had a 42.5 percent increase in acreage). At the same time, though, the Westlands table shows that the acreage in tree and vine crops–remember the dead orchards?–has increased by 20 percent since the drought began. Most of that jump has been in almonds, which grew from 55,000 acres in 2006 to 70,000 acres in 2008 before falling back to 67,000 acres last year.

Now, there is no question at all that the district, which includes about 1,000 square miles along the western fringe of the mid-San Joaquin Valley, has been hit hard by the shortage of water. It’s dry country and because the district was formed relatively recently (in the 1950s), it’s near the bottom of the totem pole for getting a share of the water pumped into the valley from up north. Yes, land has been fallowed and fieldworkers have lost jobs–pretty much the same way that’s happened during every dry cycle. The question is whether Westlands really represents the face of the drought across the state. Reading about the plight of the district, one would hardly guess that the state’s harvest of processing tomatoes–by acreage the biggest vegetable crop in California–hit an all-time high in 2009 (data by way of the U.S.D.A.’s National Agricultural Statistics Service, in its latest “California Vegetable Review“).

Of course, the processing-tomato harvest doesn’t tell you much, either–by itself. And neither does Westlands, if your interest is understanding the wide impact of California’s water challenges. Of course, if your interest is putting the grimmest possible face on the drought to scare up support for a new round of dam- and canal-building–which is exactly what many environmentalists say the Department of Water Resources is doing–then Westlands will do just fine as a poster child.

Delta pumps–turn up the volume: The biggest water news of the week came out of the Fresno courtroom of U.S. District Court Judge Oliver W. Wanger (W. is for Winston, not Wendell; and those who know say his last name rhymes with “ranger”) in a case featuring Central Valley chinook salmon, federal fishery and water managers, and (again) the Westlands Water District. On Friday, Wanger issued a temporary restraining order that blocks a federal plan to protect endangered chinook salmon that migrate back and forth through the Sacramento-San Joaquin Delta. The plan limits, but does not halt, exports from the Delta to avoid sucking fish into the pumps that send water south. Westlands and other water districts argued that pumping limits are letting hundreds of thousands of acre feet of water escape into the ocean instead of being shipped to San Luis Reservoir, the main storehouse for San Joaquin Valley irrigation supplies. Letting the water flow out to sea would amount to irreparable harm to communities depending on it for growing crops and providing jobs.

Wanger agreed, issuing a 23-page decision that sets aside the federal protection plan for two weeks, pending a permanent ruling. He found a) that recent pumping in the Delta hasn’t killed enough endangered winter-run chinook to threaten the species’ survival; b) that our wet weather has caused flows that ought to be captured now; and c) that the federal defendants have brought this ruling on themselves by failing to assess the impact of their salmon plan on people. A portion of the ruling that’s gone generally unnoticed, as far as I can tell, acknowledges that it’s unknown what effect increased pumping will have on migrating juvenile winter-run salmon. That being the case, “the temporary restraining order … shall initially be for a period of fourteen days, subject to renewal by plaintiffs upon an affirmative showing that neither the species’ nor their critical habitat will be jeopardized by continued injunction” of the pumping limits (emphasis mine). In other words, Westlands and company will need to prove that the increased flow of water they’re getting hasn’t caused a big jump in the number of salmon killed off at the pumps. (You can follow the dead salmon count at home, if you’re inclined: the federal Central Valley Project, which runs one set of the pumps in question, publishes a daily report, Chinook Salmon Loss Data.)

The key piece of Wanger’s decision, though, is not really about the amount of water being pumped out of the Delta. It’s about the winning legal strategy (in this court, anyway) used by Westlands and its allies in arguing that the agencies trying to enforce the Endangered Species Act must weigh their actions’ impact on human communities. The judge seems to be saying, “Yes, you can protect plants and animals that we humans have driven to the edge of extinction–but only if protecting them doesn’t harm us humans.” Wanger made a similar ruling last year in a case involving endangered species protection for the delta smelt. Legal Planet, an environmental law blog from UC-Berkeley and UCLA, called his findings “curious” and said, “Judge Wanger is asking the agency to balance on an absolute knife edge, ensuring that it doesn’t deny farmers a single drop of water that the fish don’t critically require.”