Lake Oroville Spillways February 18, 2017
Here’s the release from Douglas County:
Five rural Douglas County fire protection districts that respond to incidents in the Pike National Forest area received needed funds to help them manage wildland fires, medical emergencies or structure fires.
These five fire districts were awarded $100,000 in federal funds by the Board of Douglas County Commissioners. The districts will use the money over the course of the year to update wildland fire equipment, purchase new rescue equipment, pay for training and improve their communication mechanisms.
“Volunteers and staff from these fire districts are often the first responders on an incident in the Pike National Forest,” said Douglas County Commissioner and Board Chair Roger Partridge. “Consistent with the Board of County Commissioners Public Safety priority, we work in partnership with these districts as we prepare for and respond to incidents within Douglas County. We recognize how important this funding is to their ability to protect and serve.”
Money was distributed to the five agencies, based on the number of calls they made during the year, at an average of $675 per call. Awards were as follows:
Jackson 105 Fire Protection District: $21,620 (32 calls) Larkspur Fire Protection District: $4,745 (7 calls) Mountain Communities Volunteer Fire Protection District: $29,045 (43 calls) North Fork Fire Protection District: $22,295 (33 calls) West Douglas Fire Protection District: $22,295 (33 calls)
Douglas County — like many other local governments that have non-taxable federal lands within their boundaries — receives a Payment in Lieu of Taxes (PILT) annually from the federal government to help offset losses in property taxes spent on the utilization of County services on non-taxable federal lands.
Beginning in 2002, Douglas County designated a portion of its PILT money to provide supplemental funding for the five rural fire districts.
Snowex is hoping to determine how to measure the effect of the tree canopy on snowpack, snow depth, and snow density, all from space. This is the first year for SnowEx and is an intense data collection phase. An airplane is used as a proxy for satellite observations during this phase which also includes a ground effort on Grand Mesa (forest canopy site) and in the Senator Beck Basin (high altitude alpine site).
The team will spend next year examining the data and hoping to model a combination of sensors (multi-sensor approach) that correlates with the ground data sites. Edward Kim (NASA) called this, “ground-truthing.”
Years 3, 4, and 5 are lined-out for more data collection.
The other two speakers, Karl Wetlaufer (NRCS), and Frank McCormick (USFS), spoke about current snowpack estimation methods, the importance of estimation of the tree canopy effect, and the potential benefits of SnowEx.
Kim listed the benefits:
1. Water is critical to society — the project aims to measure the water in the snowpack to estimate runoff.
2. Forecast the potential for snowmelt floods — (9 of the most devastating floods in US history were snowmelt driven). Forecast drought.
3. For national security reasons it is important to know who has snow, and therefore water supply.
4. Forecast changes in climate.
Snow surveys have always been a cooperative effort in the water community, he explained, citing participation by ditch companies, the NRCS, municipal providers, and others. Federal funding fired up in 1934.
Rani Gran (NASA) said that the science was at the frontier of snow science.
Frank McComick said that the USFS has been the lead agency concerned with snow water equivalent for over a century. In the West, he said, 80% of water supply comes from snowmelt from forested mountain areas.
He talked about the difficult and exacting work going on by the 100 or so ground folks including digging snow pits, from the surface to bare ground, with hand tools. At times the temperatures are well below zero. He said work in the Senator Beck basin was suspended earlier this week due to 60mph winds and white-out conditions, even though it was not snowing at the time. The field crews have been working since February 6th and plan to end the field work on the 20th.
I really liked talking to the Navy crew.
The survey requires low-level flying over the mountains. One of the pilots talked about the Rockies and how she was psyched at the chance to catch some of the views.
The other pilot was enthusiastic about his role on the team, helping the scientists aboard the aircraft accomplish their goals.
Oroville, the aerospace engineering program at CU, water rights, Colorado’s position as a the “Headwaters State”, the flood of September 2013, and how mountains concentrate streamflow, all came up in my conversations with the team members.
Thanks to Rani for organizing the event.
Click on a thumbnail graphic below to view a gallery of photos from the event.
From Water Deeply (Laura Feinstein, Peter Gleick):
Let’s not let a good crisis go to waste: Here are six important conversations that need to happen in the aftermath of problems at Oroville Dam in Northern California.
A critical question is whether the main spillway will be serviceable for the remainder of the winter. Dam managers must continue to release water down the damaged main spillway to maintain flood space behind the dam for coming storms and spring snowmelt. Bill Croyle, acting director of DWR, told the Sacramento Bee this past Sunday that his agency is not seeing further erosion of the main spillway at current flow levels of 100,000 cubic feet per second (cfs). Managers also shut down the turbines at the base of the dam that normally release up to 15,000 cfs because of downstream obstructions.
If another storm sends water into Oroville Lake faster than it can be released via the turbines and main spillway, then water could again over flow the concrete wall that forms the top of the emergency spillway. If the hillside beneath erodes further, this wall could collapse or be undermined, sending massive amounts of water downstream causing damaging, life-threatening floods.
Sacramento Bee has a concise recap of events here.
Can We Prevent These Types of Dam Crises in the Future?
It’s well-documented that the United States has chronically underfunded dams, levees, drinking water and wastewater infrastructure for years. The Association of State Dam Safety Officials estimates the cost of known needed repairs for the country’s 2,000 deficient, high-hazard dams at $21 billion. Drinking water, wastewater, waterways, ports and levees need repairs too. The American Society of Civil Engineers in a 2013 report put the unmet funding needs of our water infrastructure at $187 billion by 2020 (calculated in 2010 dollars).
Had the emergency spillway been lined with concrete, as was recommended in a motion filed by Friends of River, Sierra Club and South Yuba River Citizens League in 2005, it might have prevented the erosion that occurred this past weekend. In hindsight, it’s easy to see that this would have been a worthwhile investment compared to the cost of repairs, mass evacuations, and environmental impacts.
But the Oroville spillway crisis reveals another important question we haven’t been asking about our underfunded infrastructure. That is: How much money do we need to budget for upgrades that are becoming necessary as engineering standards improve and climate change imposes greater pressures on the system? We may be on the hook for even more money than we realize.
Where Are We Going to Get the Money to Repair the Spillways?
Preliminary estimates to repair just the main spillway are in the range of $100m-$200m, according to Bill Croyle at DWR. The State Water Contractors that get their water from the State Water Project will likely have to pay for at least part of the repairs, and they will pass the costs on to their ratepayers. Three more things to note.
First, these expenses are likely to cause increases in costs for ratepayers, some of whom are already struggling to pay their water bill. Second, we should expect a vigorous debate as to who else should help foot the bill. Should residents of the floodplain pay for a portion of the repairs, since they benefit from flood control? Should all California taxpayers chip in via allocations from the General Fund or Proposition 1 Bond monies? Third, these types of public works projects cannot be incentivized with tax deductions to private companies looking to build profitable projects, as the Trump administration has proposed.
Are We Going to See More Water Emergencies as the Climate Changes?
Scientific models project, and observational data corroborates, that California’s climate is becoming more variable, with hotter, longer droughts and bigger precipitation events. The state’s water system was designed for a climate we no longer have. More extreme events are going to test the limits of our infrastructure and reveal new weaknesses in the system.
What Does This Mean for the Feather River Ecosystem?
In general, storms are good for rivers. California’s river ecosystems are adapted for big pulses of water in the winter. But the Feather River, where Oroville Dam is located, has been heavily altered by people, so these storms play out differently than they did before the river was dammed and leveed.
Feather River Hatchery spawns about 30 percent of the fall-run Chinook salmon in the state, as well as large numbers of spring-run Chinook and steelhead trout. Spring-run Chinook and Central Valley steelhead trout are listed as threatened under the Endangered Species Act; fall-run Chinook are still an important species for commercial fishing. Hatchery staff relocated five million juvenile salmon to a nearby facility, and have rigged a system to bring in municipal water to support the 1 million steelhead still at the hatchery. If hatchery operations go awry, it could impact populations of these valuable species.
The Feather River itself is still an important spawning ground for natural salmon and steelhead. But levees mean the river is restricted to a narrow channel, where rapid flows scour out the nesting grounds. Meanwhile, influxes of sediment and debris are likely to damage spawning grounds in the short run.
The Oroville Dam and the levees downstream were built for the joint goals of water storage and flood prevention, but floods are healthy for both the river and the floodplain. Long term, California should be thinking about places where it can move levees and allow rivers to reconnect with their floodplains.
Nobody wants to see people evacuated from their homes because of a potential natural disaster. The silver lining to a crisis is that it can generate political will to deal with unpleasant, chronic problems. The problems at Oroville Dam are linked to unresolved issues we have with funding our infrastructure, adapting to climate change and restoring natural ecosystems. Let’s move forward in ways that address the immediate emergency and the long-term problems.
Meanwhile, here’s a report about US dam safety from Brett Walton and Circle of Blue:
The near-failure on Sunday evening of the auxiliary spillway at Oroville Dam and the ongoing emergency operations to contain flood waters in California’s second-largest reservoir and shore up its eroding outlet are a tale of caution for the nation’s aging dam fleet.
“I think it should give many people reason to step back and take a hard look at things, including California,” wrote Martin McCann, director of the National Performance of Dams Program at Stanford University, in an email to Circle of Blue.
The Oroville emergency is unfolding in a state with a dam safety program widely regarded as the nation’s strongest. McCann agreed that California’s efforts to prevent a partial collapse of Oroville’s auxiliary spillway should be a wakeup call for other states with less vigilant dam regulation. Alabama, for instance, has no state dam oversight at all.
Already the top spending state for dam safety, both in total dollars and inspectors per dam, California increased its program budget by six percent between 2014 and 2016, to $US 13.3 million. The Department of Water Resources’ Division of Safety of Dams has roughly one employee per 20 state-regulated dams. That is far greater than the national average of one employee per 200 dams, according to data from the Association of State Dam Safety Officials.
“California has had a strong dam safety program for many decades,” McCann said. “It’s well-funded, well-staffed, and they inspect regularly.”
Dam safety experts cite money as the most significant impediment to safer dams. Though California spends big on oversight, the cost of repairs has emerged as a factor in the Oroville emergency. Reporting from the Mercury News revealed that state and federal officials rejected an appeal from three environmental and civic groups in 2006 to line the auxiliary spillway with concrete. The groups were concerned that the topsoil on the hillside spillway would erode if it were ever used. February 11 was the first time that water flowed over the auxiliary spillway since the 770-ft-tall dam was completed in 1968. Use of the auxiliary spillway was necessary because of damage to the main spillway and inflows to the reservoir that nearly matched the flow of the Mississippi River at St. Louis. Officials had to evacuate as much water as quickly as possible.
Most of the more than 90,500 dams in the U.S. Army Corps’ national dam database, however, are not behemoths like Oroville. Most instead resemble Twenty-one Mile Dam, a 47-foot-tall earthen structure in Elko County, Nevada. Owned by Winecup Gamble Ranch, a 948,000-acre livestock operation, the dam burst on February 9 during heavy rain. Flood waters released by the dam chewed through 200 yards of Highway 233, which remains closed.
Two-thirds of U.S. dams are privately owned and often owners do not have funds for maintenance or repair, according to Lori Spragens, executive director of the Association of State Dam Safety Officials. Most U.S. dams are more than 50 years old and an unknown number are not built to current safety standards. The association estimates that $US 18.7 billion is needed to repair high-hazard, state-regulated dams. High-hazard dams could kill people if they failed…
The pressure on Oroville will not soon let up. The watershed above the dam is expected to get as much as eight inches of precipitation through February 21. Then in the spring, the massive snowpack, measuring twice the historical average in some spots, will melt. The California Nevada River Forecast Center estimates that water flows in the Feather River, which drains into Oroville, will peak on April 29.
All of which has state officials on constant alert. “We want to complete assessments, do corrective measures on the emergency spillway, and get it ready for potential future use here in the coming weeks or months,” said Bill Croyle, acting director of California Department of Water Resources.
From The Landslide Blog (Dave Petley):
The scale of the erosion problem at the Oroville Dam site
As the fairly desperate attempt continue to shore up the spillways at the Oroville Dam site, and to lower the water level ahead of the next rainstorm, better images are emerging of the scale of the problems on both spillways. If we start with the main spillway, which suffered the original erosion events last week, it is hard to appreciate the serious nature of the problems. However, this image (via the Sacramento Bee) from the weekend shows workers in the hole eroded in the main channel:-
Of course the high flows down the spillway since then are likely to have exacerbated the problem significantly. Meanwhile, the headward erosion problem in the emergency spillway is now garnering most of the attention, primarily because of the potential for a major collapse. This image, from Hamodia, shows the nature of the erosion that has developed at multiple locations immediately down slope of the emergency spillway at the Oroville dam site:
The most serious problem appears to be a gully towards the bottom of the image, but there is also substantial amounts of erosion occurring on the other side too. The danger is of course that the these gullies will suffer headward erosion until they undermine the spillway lip. whereupon collapse may occur. One challenge is that the quality of the rock does not appear to be high, which accounts for the rapid erosion in both cases. This image, via Twitter, shows the nature of the bedrock with which the crews are dealing:-
The challenges are substantial. Fortunately, as before, there is no threat to the dam itself.
From the Associated Press via The U.S. News & World Report:
HOW IMPORTANT IS LAKE OROVILLE?
Lake Oroville is the starting point for California’s State Water Project, which provides drinking water to 23 million of the state’s 39 million people and irrigates 750,000 acres of farms. It is the largest reservoir in the system, which was built in the 1960s and early 1970s to carry rain and snowpack from the Sierra Nevada mountains to parts of the San Francisco Bay area, Central Valley and Southern California.
Lake Oroville, completed in 1967, is a cornerstone of the system of 34 reservoirs, lakes and storage facilities, built and operated by California’s Department of Water Resources. It feeds into the Feather River — about 70 miles north of Sacramento — as well as the Sacramento River and the Sacramento-San Joaquin River Delta. From there it travels south on the 444-mile California Aqueduct.
Oroville’s storage capacity of 3.5 million acre-feet of water is enough to supply urban California for up to six months, said Peter Gleick, president emeritus of the Pacific Institute, a water research organization based in Oakland, California.
“The risk of losing Oroville is very, very low” he said. “The consequences would be catastrophic.”
WHAT ARE SPILLWAYS?
When reservoirs get too full, their operators release extra water down long channels, or spillways, designed to carry it downstream in a safe, controlled way.
Oroville Dam has a main concrete spillway that normally is used to release floodwaters into the Feather River downstream. A second spillway mainly made of earth serves as an emergency backup. It also was supposed to be able to handle high flows from the dam, but it had never been used before Saturday.
The force of water [released] from the lake has damaged both spillways.
WHAT CAUSED THE FLOOD THREAT?
After five years of drought, a wet winter has strained the system at Lake Oroville, which is receiving runoff from melting snow in the Sierra Nevada as well as from the latest in a series of heavy storms.
Dam operators noticed chunks of concrete in the main spillway on Feb. 7. When workers stopped releasing water to investigate…With the reservoir nearing the top of the 770-foot-high dam, dam operators were forced to keep using the main spillway despite increasing damage to it from the rushing water.
The dam reached capacity Saturday, sending water surging over the second, emergency spillway. Operators on Sunday noticed water was gouging a hole in the earthen emergency spillway as well. Fearing that the emergency spillway could fail and send torrents of water rushing downstream uncontrolled, authorities ordered the evacuation Sunday evening.
BESIDES OROVILLE, WHERE DOES CALIFORNIA GET ITS WATER?
The Central Valley Project, operated by the U.S. Bureau of Reclamation, irrigates more than 3 million acres of farms and provides enough drinking water for more than 1 million people. The system of 22 reservoirs was built from 1937 to the 1950s, extending about 400 miles from the Cascade Mountains near Redding to the Tehachapi Mountains near Bakersfield. It includes Shasta Lake, the only reservoir in California that’s larger than Oroville.
The Colorado River supplies 19 million urban dwellers in Southern California through a 242-mile aqueduct from Lake Havasu, Arizona, to the state’s coastal regions that was completed by Metropolitan Water District of Southern California in 1941. The Colorado also farms California’s Imperial Valley — a major source of the nation’s winter vegetables — through the 80-mile All-American Canal that hugs the state’s border with Mexico.
Other significant pieces of the state system include the Los Angeles Aqueduct, which carries water from Mono Lake to the city of Los Angeles, and the Hetch Hetchy reservoir in Yosemite National Park, which supplies the San Francisco Bay area.
Gov. Jerry Brown is asking the Trump administration for federal assistance in responding to a potential failure of a spillway at the Oroville Dam in Northern California.
In a letter to President Donald Trump released Monday, Brown asks for help for the three Northern California counties affected.
Brown says aid is needed to assist the 188,000 residents of Butte, Sutter and Yuba counties who were ordered to evacuate Sunday after concerns an emergency spillway could give way, unleashing a gush of water to downstream towns.
Brown has criticized Trump on many of his initiatives, but at a news conference Monday he lauded the president’s plan to invest $1 trillion on infrastructure.
The governor says California and Washington will work “in a constructive way” to repair failing infrastructure in the state…
The California Department of Water Resources says helicopters are dropping loads of rock on a hole at the lip of Oroville Dam’s emergency spillway.
Workers are hoisting giant white bags filled with rocks and at least two helicopters flying them and releasing them in the spillway’s erosion. Dump trucks full of boulders also are on their way to dump their cargo on the damaged spillway.
The barrier at the nation’s tallest dam is being repaired a day after authorities ordered mass evacuations for everyone living below the lake out of concerns the spillway could fail and send a 30-foot wall of water roaring downstream…
California’s U.S. senators are calling on President Donald Trump to approve a disaster declaration for the state in response to damage from recent storms.
Sens. Dianne Feinstein and Kamala Harris wrote in a letter Monday that the situation is especially dire downriver from Oroville Dam, where damage has threatened flooding and forced nearly 200,000 people to evacuate.
The senators are asking the president to provide $162.3 million in disaster assistance that California requested.
The lake behind Oroville Dam swelled significantly with this winter’s rains and the collapse of its damaged spillway threatens to flood downstream communities.
From the Associated Press (Olga R. Rodriguez and Don Thompson) via The Colorado Springs Gazette:
Nearly 200,000 people who were ordered to leave their homes out of fear that a spillway could collapse may not be able to return until the barrier at the nation’s tallest dam is repaired, a sheriff said Monday.
Butte County Sheriff Kory Honea gave no timetable for the work. Officials from the California Department of Water Resources were considering using helicopters to drop loads of rock on the eroded spillway at Lake Oroville, about 150 miles northeast of San Francisco.
Meanwhile, the water level behind the dam dropped, easing slightly the fears of a catastrophic spillway collapse. But with more rain expected later in the week, time was running short to fix the damage ahead of the storms.