BILL ANALYSIS Ó
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|SENATE RULES COMMITTEE | SB 758|
|Office of Senate Floor Analyses | |
|(916) 651-1520 Fax: (916) | |
|327-4478 | |
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THIRD READING
Bill No: SB 758
Author: Block (D)
Amended: 6/2/15
Vote: 21
SENATE NATURAL RES. & WATER COMMITTEE: 8-0, 4/28/15
AYES: Pavley, Stone, Allen, Hertzberg, Hueso, Jackson,
Monning, Wolk
NO VOTE RECORDED: Vidak
SENATE APPROPRIATIONS COMMITTEE: 7-0, 5/28/15
AYES: Lara, Bates, Beall, Hill, Leyva, Mendoza, Nielsen
SUBJECT: Atmospheric Rivers Research and Mitigation
ProgramAtmospheric Rivers Research and Mitigation
Program.
SOURCE: Author
DIGEST: This bill requires the Department of Water Resources
(DWR) to research the cause and effects of atmospheric rivers
and to take all actions to capture water generated by
atmospheric rivers.
ANALYSIS: Existing law establishes DWR to manage the state's
water resources. Within DWR is the Hydrology and Flood
Operations Office that is responsible for directing DWR's flood
and water supply forecasting operations, hydrology and
climatology studies, emergency flood operations, and flood
control project inspections and encroachment permitting. The
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Office also includes the California State Climatologist.
This bill:
1)Establishes the Atmospheric Rivers and Research and Mitigation
Program.
2)Requires DWR, upon appropriation of special fund moneys,
including private funds, to study the causes and effects of
atmospheric rivers.
3)Requires DWR to take actions, including through reservoir
management, to increase water supply and reliability of water
resources by capturing water generated by atmospheric rivers.
Comments
What are atmospheric rivers? According to the National Oceanic
and Atmospheric Administration, atmospheric rivers are
relatively narrow regions in the atmosphere that are responsible
for most of the horizontal transport of water vapor outside of
the tropics. On the west coast, 30-50% of the annual
precipitation on average comes from a few atmospheric river
events.
Current operation of flood control dams. When dams are built
for flood control, a flood operations curve is developed to
govern flood operations throughout the year. Also known as "rule
curves," these curves define how full a reservoir can be for
each day of the year, versus how much space must be reserved for
potential flood flows. Rule curves are determined based on an
analysis of historic weather and runoff patterns and the
potential economic loss due to flooding.
Because most of California's dams were built in the mid-1900s,
the historical record used to create rule curves includes only
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the first half of the 20th century. While our knowledge of and
ability to forecast weather has improved, and land use patterns
have changed significantly since the initial rule curves were
calculated, the rule curves have not typically been updated.
Indeed, one common complaint about rule curves is that they do
not take into consideration weather forecasts.
FISCAL EFFECT: Appropriation: No Fiscal
Com.:YesLocal: No
According to the Senate Appropriations Committee:
One-time costs of $2.5 million to unspecified special funds and
private funds to DWR to expand its extreme precipitation
network.
Ongoing costs of $1.25 million to unspecified special funds and
private funds to operate and analyze the expanded extreme
precipitation network.
One-time costs of $500,000 to unspecified special funds and
private funds to DWR for a study to improve predictability of
the formation and strength of atmospheric rivers.
SUPPORT: (Verified5/29/15)
Bay Area Flood Protection Agencies Association
Orange County Water District
Sonoma County Water Agency
OPPOSITION: (Verified5/29/15)
None received
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ARGUMENTS IN SUPPORT: According to the author, "California
has the most variable precipitation annually of any location in
the U.S., ranging from severe drought to major floods. Research
has shown that this variability is largely due to a weather
condition known as 'atmospheric rivers' (AR). AR are responsible
for 30-50% of California's precipitation and water supply in
just a handful of days each year. Pineapple Express Storms are
a common example of AR. Better forecasting of ARs (from hours,
to days, weeks and seasons) has the potential to enable new
levels of both water supply and flood protection through the use
of 'Forecast-Informed Reservoir Operations' (FIRO). A pilot
project to test the feasibility of FIRO is being planned by an
expert committee on a vital reservoir on the Russian River, Lake
Mendocino. It is led by researchers at the Center for Western
Weather and Water Extremes at the University of California San
Diego and the Sonoma County Water Agency. This pilot project has
the potential to predict AR patterns to make intelligent water
management decisions in order to both collect additional water
supply and protect against floods. Seasonal AR outlooks are
another promising direction that could help water managers and
emergency preparedness officials anticipate and prepare for
drought and/or flood. Developing such outlooks is on the
cutting edge of science today and SB 758 ensures the state
develops a program to study AR."
Prepared by:Dennis O'Connor / N.R. & W. / (916) 651-4116
6/2/15 16:00:07
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