HomeMy WebLinkAboutStatus of Spillway 02-09-17 Menchaca, Clarissa
From: Hahn' Pau|
Sent: Thursday, February Q' 2O17Q:55AK4
To: Connelly, Bill; Kirk, Maureen; Lambert, Steve; Teeter, Doug;Wahl, Larry
Cc: Dept Heads; CAO Administration (All Employees)
Subject: FW: Status of Lake (]rov||e spillway (Spillway Incident)
Board Members,
Here is an update from Darren Read sent this morning regarding latest on {}rovi||e Spillway incident. Cal-Fire staff ia
now imbedded into the UVVR/OES command structure and aiding in the event, which should help our communication. |
want toreiterate that the dam itself ianot indanger. AUVVRbriefing iaoccurring at1Ua.m, and aa |get additional
information, itwill bepassed on. Our E{}Cstaff, Sheriff, Fire,Administration and Public Works staffs will continue to
monitor the situation very closely.
Thanks,
Pau| MahD
Chief Administrative Officer/CAO
2.5 C..o.jg.int Center [Irive Suite 200 Oroville
Phahn(cDbuttecounty.net
T: 530.538.7831
From: Read, Darren@CALF|RE [mai|to:Darren.Read @fireza.gov]
Sent:Thursday, February 9, 20177:39AM
To: Hahn, Paul <PHahn@buttecounty.net>; Pickett,Andy<APickett@buttecountyoet>; Honea, Kory
<KHonea@buttecountyoet>; Dunomoor, Cindi<CDuins moor@buttecounty.net>
Cc: Read, Darren <Darnen.Read @fireza.gov>
Subject: Fvv: Status ofLake OroviUespillway(Spillway Incident)
All,
Anupdate onthe Spillway Incident.
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N� Read
Unit & Fire Chief
CAL FIRE Butte Unit
Butte County Fire Department
z
Proudly Serving the Cities of Biggs, Gridley& Town of Paradise
From: Read, Darren@CALFIRE
Sent:Thursday, February 9, 2017 7:35 AM
To: CALFIRE BTU; CALFIRE BTU Volunteers
Subject: Fw: Status of Lake Oroville spillway(Spillway Incident)
BTU,
As you most likely know on Tuesday February 7, 2017, DWR stopped the flow of water over the Oroville Dam
spillway due to erosion and concrete damage concerns on the spillway itself. Upon inspection DWR
found significant concrete damage and erosion to the spillway.
As of early yesterday morning we assigned BC Russ Fowler as the CAL FIRE Agency Rep for the Spillway
Incident. We wanted to be included in the planning process for this incident for many reasons the most
important being the potential for flooding down stream from the lake due to the current lake levels and
storage capacity and future predicted wet storms.
As of late last night DWR made a formal request to our Sacramento ECC Duty Officer for CAL FIRE to assist
them with this incident. We will be assist DWR with incident planning, information, and
contingency operations. DWR and CAL FIRE have an MOU for emergency flood fighting operations that CAL
FIRE is working within. This is not an OES mission tasking operation. OES has been notified that CAL FIRE is
assisting DWR within our MOU.
As of this morning the following CAL FIRE resources have been assigned:
1 Agency Rep
1 PIO
1 GIS Specialist
1 Safety Officer
1 Division Group Supervisor
2 Fire Crews
4 dozers
Below are updates from Chief Fowler from last night.
Darren Read
Unit & Fire Chief
CAL FIRE Butte Unit
Butte County Fire Department
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Proudly Serving the Cities of Biggs, Gridley& Town of Paradise
Update on the Lake Oroville Spillway situation February 8, 2017 at 2130 hours:
Spillway test went well, performing better than expected. The south undermined wall collapsed, but it was
expected. The erosion has slowed because the hydraulics are getting into solid bedrock, which was
expected. Flows will resume out of the spillway at 20,000 CFS tonight through tomorrow AM at 0700. They
will shut off flow for 2 hours in the morning for a hasty evaluation and then restart flows at 20,000 CFS around
0900, with possible increases to 25,000 to 30,000 CFS down spillway. The total flow in the river channel will
not exceed 44,000 CFS under the 30,000 CFS release scenario.
Cal Fire resources will begin working the Morris Ravine tree removal project tomorrow with crews and
dozers. This will make a shoot for the water to flow through should the emergency spillway come into
play. Removing this vegetation will help reduce debris flow into the river channel which will help protect the
Diversion Dam infrastructure. DWR does NOT expect the emergency spillway to come into play in the short
term, possibly not at all.
Update on the Lake Oroville Spillway situation February 8, 2017 at 1900 hours
This morning DWR staff evaluated the large hole that was created in the spillway yesterday at about 0930 (for
unknown reasons). The damage is about 2/3 of the way down the spillway, with the hole depth ranging from
3' to 45'. The south wall of the spillway is compromised due to hydraulic undermining. Today at 1400 DWR
began increasing flows down the spillway in order to test it (20,000 CFS by 1600). This resulted in a total rise
in the river of about 5' in the low flow section. The total flow through HYPP is now at 14,000 CFS (all 5
penstocks are operational, river valves are not currently operational). This equals a total outflow of 34,000
CFS (26,000 through the low flow channel).
At 1800 today DWR reduced spillway flows to zero to begin assessing the hole/damage. After assessments
tonight they will make decisions on future spillway use. It is preferred to use the normal spillway for up to
30,000 CFS starting tomorrow. This will allow total releases of 44,000 CFS, which is projected to keep the lake
below 997' through the period of 2/19, in which the level should start to recede very slowly. This is taking into
account the forecasted storm next weekend. If they can use the spillway, which looks promising, we should
avert an uncontrolled flow scenario and maintain a river of no more than 44,000 CFS, which is no threat to the
public outside of the river channel.
If the uncontrolled scenario does play out the outflows into the river will be the same as inflows into the
lake. This is not a predicted scenario, but cannot be ruled out.
For our plans, I am working on 3 options/levels of concern:
3
1. Controlled release (additional debris into channel)
2. Uncontrolled release within design of river channel (additional debris into river and damage to
infrastructure, no flooding outside of river channel)
3. Uncontrolled release, exceeding design of river channel (possible river breaches and mass flooding)
With all of these scenarios there is NO scenario predicted that could cause a catastrophic breech of the Dam.
DWR has requested CalFire to assist with heavy equipment and overhead for the "grubbing" of the area below
the emergency spillway, beginning tomorrow at 0800. Cal Fire dozers and overhead will be assigned for up to
3 days to accomplish this task. DWR will enter into a emergency rental agreement with CalFire for
reimbursement.
More to follow after our 1930 meeting tonight
Russ Fowler
Battalion Chief(Bat-6)
CAL FIRE- Butte County Fires
176 Nelson Ave
Oroville,CA 95965
(530)521-8056
russ.fowler(a firexa.aov
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