For the second day in a row, a torrent of water on Sunday flowed over the Anderson Reservoir spillway, marking a phenomenon that hadn’t happened for 11 years until this weekend. The Morgan Hill reservoir hovered around 101.4 percent of its maximum capacity as of Sunday afternoon, but that number could rise as an impending storm barrels toward the Bay Area.
Waterlogged Northern California will get more heavy rainfall into Wednesday, renewing fears about flooding in the region. The new onslaught of rain comes as Southern California dries out following downpours that left five people dead. A flood warning is in effect for Northern California’s interior counties through Thursday. Storms started overnight Saturday, with two to four inches of rain expected by Wednesday, CNN meteorologist Allison Chinchar said. Some areas may get up to 10 inches and the driving rain could drastically reduce visibility, Chinchar warned.
California Department of Water Resources officials reached their goal of getting water levels in Lake Oroville 50 feet below the dam crest Monday.The reservoir reached 50 feet below capacity as of 6 a.m. Monday. The 850-foot mark is important because it gives ground crews more flexibility for water flowing into the lake during this week’s storms, DWR officials said. “It allows us to lower our outflows from the dam, so we can start working on the diversion pool,” said Chris Orrock, a DWR spokesman.
By now we have all seen the spectacular images of volumes of water crashing down the Oroville Dam spillway in California and blasting upward into the air as they hit an enormous crater in the spillway floor, flooding down the adjacent hillside, threatening people in towns below. Those images reveal a big mistake: failure to update infrastructure to defend against climate change.
Earlier this week, while areas downstream of Oroville Dam were still under an evacuation order, California’s State Water Resources Control Board released a draft resolution for a comprehensive response to climate change. It resolves that the agency will embed climate science into all its existing work, both to mitigate greenhouse gas emissions and to build resilience to the impacts of climate change. In doing so, the state water board demonstrates how public agencies can respond more proactively to the challenges that global warming is bringing our way.
In a region that has seen so much drought over the last decade, the prospect of moisture would be a welcome one. But right now, not so much. The state of California has seen more moisture in the last few weeks than it typically gets in a year and this could actually turn into their wettest “wet season” on record. Several more inches of rain looks likely for northern and central parts of the state with the highest elevations getting several more feet of snow.
Just because nature allows a delay of many years while officials dither over a catastrophe in the making doesn’t make that disaster any easier to handle when it finally strikes. This is one major lesson of the Oroville Dam spillway crisis that saw the sudden evacuation of almost 200,000 persons from their homes when the dam’s emergency spillway crumbled under the force of millions of gallons of fast-moving water. Warnings of precisely this sort of crisis at Lake Oroville were submitted to the Federal Energy Regulation Commission during a 2005 relicensing process, almost 12 years before those predictions came true.
It’s raining in California. Again. A storm system hitting north and central California on Monday and Tuesday will deliver two to three inches of rain to the Central Valley, and up to 10 inches of rain to the mountains, said Eric Kurth, a meteorologist with the National Weather Service in Sacramento. The service has issued a flood warning through Wednesday across most of the Sacramento River Valley and the surrounding areas.
Oroville Dam’s badly damaged main spillway is still deteriorating from an onslaught of fast-paced water, but state officials insist that it is “stable” as they make repairs. State officials expected the concrete main spillway to erode last week when they opened its gates, betting that it was a safer option than the dam’s little-used emergency spillway.
You hear this every time there’s a drought or deluge in California: “Why haven’t they built more dams?” Truth is, they’ve built a bunch. And they’re about done with it. Tally them up. There are more than 1,400 dams in the state. At least 1,000 are major and 55 can hold 100,000 acre-feet or more of water. One acre-foot is enough to supply two average households for a year. There are 36 reservoirs that can contain at least 200,000 acre-feet. Eleven can hold 1 million or more.
