Issued by NWS San Francisco Bay Area, CA
WGUS86 KMTR 211245
National Weather Service San Francisco CA
445 AM PST SAT JAN 21 2017
Santa Clara CA-San Benito CA-
445 AM PST SAT JAN 21 2017
...THE FLOOD ADVISORY FOR A DAM FLOODGATE RELEASE REMAINS IN EFFECT
UNTIL 345 PM PST SUNDAY FOR SOUTHEASTERN SANTA CLARA AND NORTHWESTERN
SAN BENITO COUNTIES...
* Local Water District and County Emergency Management personnel
have indicated that limited portions of the spillway structure for
Pacheco Lake have been compromised from prior storm activity and
spillway releases this winter. Specifically, there is concern that
renewed spillway releases anticipated in response to forecast
rainfall through the remainder of this weekend could cause
additional erosion of the spillway structure, which could lead to
excessive sediment and/or runoff to enter Pacheco Creek
downstream. Excessive runoff and sediment could cause or increase
* NWS Monterey is forecasting an additional 1-2" of rainfall this
weekend in the Pacheco Creek watershed that feeds the reservoir.
Development of post-frontal convective thunderstorms over the
watershed could increase local precipitation totals over the
weekend. Rainfall this weekend will likely be accompanied by
increased releases over the spillway, but it is currently not
expected that additional releases would pose additional risk to
the spillway or downstream areas.
* Engineers from the local Water District as well as California
Division of Safety of Dams and California Department of Water
Resources engineers are on-site conducting inspections and
assessing the level of risk posed by current and expected
conditions. County Emergency Managers are aware of the situation
and are taking appropriate action and following necessary
* There is no expectation at this time that a dam breach or failure
would occur. The dam itself is not compromised; it is only the
spillway structure that is under investigation.
* Should the situation worsen and elevate the threat to human life
and property, either prior to or during storm activity this
weekend, a Flash Flood Warning will be issued for affected areas.
Stay tuned to your wireless emergency alerts via cellular phone,
Emergency Alert System interruptions on local radio and television
stations, NOAA Weather Radio, Twitter (@NWSBayArea), Facebook
(NWSBayArea), and other local news and notification services
should a Flash Flood Warning be necessary.
Turn around, don`t drown when encountering flooded roads. Most flood
deaths occur in vehicles.
Be especially cautious at night when it is harder to recognize the
dangers of flooding.
LAT...LON 3710 12127 3704 12127 3697 12133 3687 12136
3687 12145 3689 12150 3690 12157 3696 12154
3699 12149 3699 12144 3697 12141 3709 12131