BILL ANALYSIS �
Senate Appropriations Committee Fiscal Summary
Senator Kevin de Le�n, Chair
SB 1259 (Pavley) - Dams: sedimentation studies.
Amended: May 5, 2014 Policy Vote: NR&W 9-0
Urgency: No Mandate: No
Hearing Date: May 23, 2014 Consultant: Marie Liu
SUSPENSE FILE. AS AMENDED.
Bill Summary: SB 1259 would require the Department of Water
Resources (DWR) to conduct a study regarding the loss of storage
capacity behind dams resulting from siltation by January 1, 2017
and would require that the results be included in the California
Water Plan.
Fiscal Impact (as approved on May 23, 2014): Cost pressures of
approximately $10 million from the General Fund to DWR to
conduct sedimentation studies of the reservoirs in the state.
Background: Existing law charges DWR with supervising the
construction, enlargement, alteration, repair, maintenance,
operation, and removal of dams and reservoirs for the protection
of life and property. Under this authority, DWR has sediment
removal projects for five dams. While it is recognized that
sedimentation can significant reduce dam capacity, there is no
robust information on statewide impact of sedimentation on
statewide water supplies.
The California Water Plan is the state's master plan which
guides the orderly and coordinated development, management, and
efficient utilization of the water resources of the state. DWR
is required to update the Water Plan every five years.
Proposed Law: This bill would require DWR to investigate the
loss of storage capacity behind dams resulting from
sedimentation. The study may be based on data from dam operators
and other sources, modeling, and evaluation of sediment for
mercury and sediment grain size. The study would be required to
include evaluation of cost-effective strategies for sediment
removal.
The initial study would be required to be completed by January
SB 1259 (Pavley)
Page 1
1, 2017. Results from these studies would be required to be
included in the California Water Plan and transmitted to the
Legislature.
Staff Comments: DWR estimates that conducting the study required
by the bill would cost at least $30 million assuming that only a
fourth of the 1250 state-regulated dams would need to be
evaluated for the purpose of this study and that evaluation at
each dam would cost $100,000 per dam. Staff notes that this cost
estimate is for a one-time study.
Staff notes that the bill is unclear how much flexibility DWR
has in focusing the study on high priority dams, with priority
being determined by dam purpose, capacity, state-wide or
regional significance, or other factor and excluding
low-priority dams. The bill also does not speak to the level of
accuracy necessary for the study. As noted in the Senate Natural
Resources and Water analysis, there has been one published study
estimating sedimentation rates in California at large spatial
and temporal scales based on modeling. Presumably the cost of
this study was not in the millions of dollars, but the study's
level of accuracy is less than what the author intends.
Author Amendments: Allows rather than requires the sedimentation
study by January 1, 2017 and explicitly gives DWR discretion in
setting the scope of the study.