DAM IN DANGER OF MASSIVE SPILLWAY EROSION
AGENDA 21 RADIO
BY PAUL PRESTON
I traveled to the Oroville Dam just outside of Oroville, CA in Northern California (State of Jefferson) yesterday and got to see all aspects of the ‘broken’ spillway issue. It must be said that the large hole is in the primary spillway about 3/4 of the way down from the dam. There are two spillways a primary and a secondary.
The location of both spillways is not in the location of the dam proper but to the north of the main area of the dam. As you watch the visual from the drone note the massive erosion to the right of the primary spillway. This is a result of the water coming down the spillway and going into the hole that was created from the concrete breaking up in the spillway.
The water fills the hole and then explodes upwards into a massive mist cloud, Excess water moves to the sides of the spillway has to go some where so it leaves the spillway and exits to the right where massive erosion into the hillside is seen.
Secondary Spillway Used for the First Time in Dam History
A series of storms which has ended a 5 year drought in California has created a monster snow pack and run off from rain soaked hills and mountains has caused reservoirs, rivers and streams to fill to the top of their capacity. Lake Oroville as I was standing on top of the dam actually reached it’s capacity and started to spill water over the top of the secondary spillway for the first time since the dam was built in 1968. Run off from the secondary dam started to erode a large section just to the north of the damaged primary spillway.
At the time of this article DWR is saying there is no threat to the dam since the spillways are not a part of the dam. Time and erosion will tell how bad the damage will be if there is a threat to the dam.
Recent Oro Dam spillway inspections found nothing suspect
The Oroville Mercury Record reported that there were no major issue regarding the spillway in the last several years.
“The most recent inspection of the Oroville Dam spillway was conducted about six months ago, according to the Department of Water Resources, and nothing at the spillway seemed amiss, according to the reports.
This newspaper requested the most recent inspection reports of the spillway and received documents from August 2016, July and February 2015, and a report from June and August in 2014.
At Friday’s afternoon press conference, DWR civil engineer Kevin Dossey, said spillway voids are common and confirmed Oroville’s spillway surface was repaired in 2013 near where Tuesday’s failure occurred. He said the spillway has never undergone major repair”.
Governor Jerry Brown Silent on Potential Dam Disaster
As of the writing of this article Governor Jerry Brown has yet to comment or take a public position on safety issues regarding the Oroville Dam spillway incident. On February 10, 2017 Governor Brown issued the following: GOVERNOR BROWN REQUESTS PRESIDENTIAL MAJOR DISASTER DECLARATION DUE TO JANUARY STORMS which states:
2-10-2017
SACRAMENTO – Governor Edmund G. Brown Jr. today requested a Presidential Major Disaster Declaration for the state to bolster ongoing state and local recovery efforts following January storms that caused flooding, mudslides, erosion, power outages and damage to critical infrastructure across California.
Governor Brown also issued an executive order today that adds the counties of Amador, Mono and Riverside to the 49 counties already included in the emergency proclamation issued last month due to January storms. The order also authorizes state funding through the California Disaster Assistance Act for 34 counties impacted by the storms and directs the California Department of Transportation to formally request immediate assistance through the Federal Highway Administration’s Emergency Relief Program for Amador and Riverside counties.
The Governor’s request for a Presidential Major Disaster Declaration due to January storms can be found here and the full text of the executive order issued today can be found here.
