The U.S. Army Corps of Engineers has
developed three plans to increase the level of
flood protection for Sacramento residents from
the current 100-year level.
- THE FOLSOM MODIFICATION PLAN calls
for the permanent “reoperation” (draining)
of Folsom Reservoir each winter to make
room for seasonal flood flows, improvements
to Folsom Dam, and the 36 miles of downstream
levees. This plan would provide Sacramento
with 180-year level flood protection
(a 1 in 180 chance in any one year of
flooding). This plan includes lowering
the dam spillway and increasing release
capacity of dam river outlets, implementing
an advanced warning flood plain evacuation
plan, and improving 24 miles of downstream
levees. The Folsom Modified alternative
offers the lowest level of flood protection
of the three plans, Sacramento could
expect the highest average annual equivalent
flood damages: $90 million.
ADC comments on the FOLSOM MODIFICATION
PLAN:
Despite the planned
improvements to Folsom Dam, there still a 46% chance
of system breech and failure should a 200-year
storm event strike Sacramento. For this reason,
this plan fails to meet the minimum flood protection
standard for Sacramento set by the non-federal
cost sharing partners, the State of California
and the Sacramento Area Flood Control Agency (SAFCA).
The Folsom Modification Plan would
permanently increase the flood control space at
Folsom Reservoir negatively impacting water supply
and power generation according to the U.S. Army
Corps of Engineers. The Corps has calculated this
impact over the 100-year life of the project at
$114 million. We feel that more threatening to
the region is the lack of dependable water supplies
from Folsom Lake given recent and extended drought
periods in California. Winter storms and spring
runoff cannot always be counted upon to refill
the reservoir after Folsom has been drawn down
every winter.
- FOLSOM STEPPED RELEASE PLAN is
similar to the Folsom Modification plan. It would
add extensive modifications to 36 miles of American
River levees, Sacramento Weir and Bypass, and Yolo
Bypass levees to permit elevated releases from
Folsom Dam of up to 180,000 cubic feet per second
(cfs)-a 56% increase over the current capacity
of these levees. The Stepped Release alternative
would provide a 235-year level of flood protection
for Sacramento (1 in 235 chance of flooding in
any one year) and have a 32% chance of
breach in the event of a 200-year storm.
This plan does not meet the minimum flood protection
standards for Sacramento. Average annual equivalent
flood damage has been calculated at $80 million.
ADC Comments on the FOLSOM STEPPED
RELEASE PLAN:
The first and last
defense under the Folsom Modified and Folsom Stepped
Release Plan would be levees. According to a recent
Sacramento Bee Article “Budget cuts and environmental
regulations have compromised repairs of 1600 miles
of state-controlled levees that are part of the
Sacramento and San Joanquin flood-control projects”.
State leaders and lawmakers have also cut the flood
management budget of the Department of Water Resources
by 74%, from $116 to $30 million. DWR now admits
it can’t meet many of its flood-control obligations,
which include maintenance of essential flood channels,
such as the Yolo Bypass that shunts water around
Sacramento. According to the Bee, “some of
these erosion sites increase the flood threat to
such heavily populated areas as downtown Sacramento,
the Pocket-in south Sacramento-and Natomas, to
the North.”
Are we being pennywise and
pound foolish?
Besides environmental
concerns, much has been made about the cost
of the proposed flood control projects. But
are we being pennywise and pound foolish considering
the potential damage to over 400,000 lives
and $20 billion dollars in property? It would
seem that if we do not pay now, we’ll
pay later. In 2002, the 6 th Appellate District
of California found that Monterey County and
three other counties were responsible for
the damage from a 1995 flood that overwhelmed
levees on the Pajaro River, near Watsonville.
The 3 rd Distrct Court of Appeals found the
state liable for the 1986 levee break in Yuba
County. These rulings may very well set the
precedent that could place California risk
of facing billions of dollars in liabilities.
We can either choose to continue paying those
damages or invest in a flood control system
that will provide both flood protection and
water supply.
- Detention Dam would provide Sacramento with an extremely
high 500-year level of protection in accordance
with federal guidelines. The chance that a
200-year flood event would overwhelm the dam
and levee improvements is a minuscule 3%.
The dam would provide a level of protection
that would no longer require flood insurance.
Although
the most expensive of the three plans, the
dam alternative provides 1.5 times greater
net average annual flood control benefits
than the other two plans, together with a
benefit to cost ratio of 1.8 to 1. A 1991
report developed for Congress stated, “For
highly urbanized areas such as Sacramento,
a flood detention facility is preferred over
levees. Reliance on levees for flood
protection is inherently less safe than
an upstream detention dam.”
The Detention Dam plan would increase
water storage over the current Folsom
Reservoir reoperation plan. The potential
exists for joint flood operation of Folsom
and the flood control dam at Auburn, adding
to the region’s available
water and power supply. The Corps has
calculated this increase in water, power,
and recreation at Folsom to be $2.6 millin
each year or $58.5 million over the life of
reoperation.
ADC comments on the DETENTION
DAM
The flood control dam
significantly increases flood
protection reliability
because 894,000 acre-feet of water will be removed
from flood flows reaching Sacramento. Even flows
greather than a 500-year flood will be significantly
reduced, thereby reducing the threats to life and
property.
The Dentention Dam plan would allow
the discontinuation of the Folsom Reoperation Plan.
This would allow for higher Folsom Reservoir levels
which could benefit downstream fisheries. Higher
lake levels at Folsom Reservoir would enhance the
beauty of the lake and its recreational experience.