In dam news today, Lake Oroville nears limit, close to flowing over spillway; Use of untested emergency spillway yet again a possibility at crippled Oroville Dam; At Oroville Dam, a break in storms gives engineers hope; Saved by the sun: DWR says emergency spillway might not get used; Damage to Oroville Dam spillway worsens – could cost $100 million; What engineers are doing about the 300-foot hole in Oroville Dam’s spillway; and Department of Fish and Wildlife rescues 8 million young salmon, 1 million steelhead on the Feather River
Sat AM breaking news …
In dam news today …
Lake Oroville nears limit, close to flowing over spillway: “Anyone who’s been watching the numbers associated with Oroville Dam and Lake Oroville this evening — how much water is flowing into the lake, how much is flowing out through the partially destroyed spillway — probably has come to a conclusion similar to this one: At some point during the next few hours, water from the state’s second-largest reservoir is likely to start pouring across the dam’s emergency spillway and start racing down an adjacent slope toward the waterway below. At midnight Friday, Lake Oroville had risen to within about 18 inches of the lip of the emergency spillway. With water still coming into the lake from the Feather River watershed faster than it can be released down the damaged spillway, the level is rising at about 3 inches per hour. At that rate, simple spectator arithmetic tells you that lake will overtop the emergency spillway as early as 6 a.m. Saturday. … ” Read more from KQED here: Lake Oroville nears limit, close to flowing over spillway
Use of untested emergency spillway yet again a possibility at crippled Oroville Dam: “Pressing down on the accelerator to flush water out of their swollen reservoir, the operators of crippled Oroville Dam thought they had achieved a breakthrough Friday: So much water was cascading out over the damaged main spillway, it looked as if they could keep the lake from reaching the brim and emptying through the dam’s untested emergency spillway. But by Friday evening, more unexpected trouble: The Department of Water Resources announced it was dialing back water releases over the battered main spillway by about 15 percent to keep erosion along the side of the spillway from “compromising” the power line towers that fuel the dam’s power plant. That reduced releases to 55,000 cubic feet per second. … ” Read more from the Sacramento Bee here: Use of untested emergency spillway yet again a possibility at crippled Oroville Dam
At Oroville Dam, a break in storms gives engineers hope: “Friday afternoon the sun peaked through the clouds above Lake Oroville and a rainbow arched over the Feather River. It was a welcome sight for state engineers who were battling the lake’s worrisome rise with torrential releases down the reservoir’s broken concrete spillway. The break in storms and a drop in the volume of water pouring into the huge reservoir gave dam operators hope that they could keep lake levels from hitting an elevation of 901 feet — the point at which uncontrolled flows would start washing down an unpaved emergency spillway that has never been used in Oroville’s 48-year history. ... ” Read more from the LA Times here: At Oroville Dam, a break in storms gives engineers hope
Saved by the sun: DWR says emergency spillway might not get used: “Department of Water Resources representatives said Friday they did not anticipate needing to use the emergency spillway to control the level of Lake Oroville, even with the main controlled spillway damaged. DWR even dialed back the releases a bit on Friday evening, concerned about erosion on the north side of the spillway. “The sun is coming out. The rain has stopped. We think the inflow has peaked and it’s on its way down,” said DWR public information officer Eric See. “We hope that continues.” … ” Read more from the Chico Enterprise-Record here: Saved by the sun: DWR says emergency spillway might not get used
Damage to Oroville Dam spillway worsens – could cost $100 million: “A foaming mass of whitewater cascaded down the badly damaged Oroville Dam spillway Friday after state officials upped the flow in an attempt to avoid what would be an even more disastrous overflowing of California’s second-largest reservoir. By increasing the flow, dam operators were conceding they were likely to lose a big portion of the spillway to erosion — perhaps the entire bottom half, or about 150 yards of concrete that will have to be painstakingly rebuilt during the dry months. The cost, state officials said Friday, will likely top $100 million. … ” Read more from SF Gate here: Damage to Oroville Dam spillway worsens – could cost $100 million
What engineers are doing about the 300-foot hole in Oroville Dam’s spillway: “Heavy rains are washing away California’s drought, but now a new problem has surfaced for state officials. Engineers are scrambling to address severe damage to a concrete spillway used to release water from Lake Oroville, located about 75 miles north of Sacramento. On Tuesday, engineers discovered a massive hole in the lower half of the spillway. The gash has since grown to an estimated 300 feet wide, 180 feet long and 40 feet deep, Department of Water Resources (DWR) Spokesperson Doug Carlson told PBS NewsHour. Gushing water has launched chunks of concrete haphazardly and churned the Feather River below into mush, putting millions of steelhead salmon at a downstream hatchery into immediate danger. ... ” Read more from PBS News Hour here: What engineers are doing about the 300-foot hole in Oroville Dam’s spillway
Department of Fish and Wildlife rescues 8 million young salmon, 1 million steelhead on the Feather River: “Over 50 California Department of Fish and Wildlife staff conducted a successful relocation over the past two days of 6.5 million young Chinook salmon imperiled by raging, muddy flows of 65,000 cfs below Oroville Dam as a giant hole caused by erosion continues to expand. The California Department of Water Resources (DWR) this afternoon boosted the water release from 40,000 cubic feet per second (cfs) to 65,000 cfs with hopes that they could avoid the use of the emergency spillway at the Lake Oroville and Oroville Dam site in Butte County, according to DWR. However, the agency just issued an update saying they plan to reduce the releases to 55,000 cfs to prevent erosion along the north side of the spillway from compromising nearby power line towers. ... ” Read more from the Fish Sniffer here: Department of Fish and Wildlife rescues 8 million young salmon, 1 million steelhead on the Feather River
In dam commentary today …
Oroville Dam hole illustrates California’s infrastructure deficit, says the Fresno Bee: They write, “On the day the massive hole in the Oroville Dam spillway was discovered, the California Department of Water Resources issued a report detailing a separate and very real threat to the state’s vital water delivery system. Because of overpumping to irrigate crops during the drought, large swaths of the Central Valley in and around Chowchilla, Corcoran and the Fresno County town of Tranquility subsided rapidly in 2015 and 2016. Land subsidence in the Central Valley and the gaping hole that appeared in the spillway at Oroville Dam are not connected in any direct way. But they are of a piece. California’s plumbing system, largely built five decades ago, is outdated and in distress. We will face a reckoning sooner rather than later. … ” Read more from the Fresno Bee here: Oroville Dam hole illustrates California’s infrastructure deficit
Precipitation watch …
For all of the Notebook’s coverage of the Oroville Dam spillway damage, click here.
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About the Daily Digest: The Daily Digest is a collection of selected news articles, commentaries and editorials appearing in the mainstream press. Items are generally selected to follow the focus of the Notebook blog. The Daily Digest is published every weekday with a weekend edition posting on Sundays.
