TECHNOLOGY
The auxiliary spillway (seen on the right) at Folsom Dam,
completed in 2017, will help dissipate energy as water flows
into the American River. It is expected to improve flood
management at the reservoir, where water can be released
at 160,000 cubic feet per second. PHOTO COURTESY OF THE
CALIFORNIA DEPARTMENT OF WATER RESOURCES/FLORENCE LOW
supply, f lood risk, en-
vironmental, and other
benefits,” says Micheal
Konieczki, senior hydro-
logic engineer with HDR
in Sacramento.
Predicting
the future
bounced back after being submerged
34 years ago. The risk of flooding and
potential high costs for flood insurance
have deterred population growth in
Yuba County since the floods, James
says, adding that studies count almost
$4 billion of damageable property down-
stream in Yuba County alone ($12 billion
in the Yuba-Sutter region).
Last year, the Yuba Water Agency,
with Scripps and the California De-
partment of Water Resources, launched
FIRO projects at New Bullards Bar and
Oroville dams to improve forecasts and
reduce flood risk. A secondary spillway
is also in progress at New Bullards Bar
Reservoir, set to be completed by 2024-
25. According to James, FIRO provides a
“climate resiliency tool” to help reduce
flood risk and potentially increase
water supplies for stakeholders (resi-
dents, farmers, fisheries, aquifers, etc.).
Through the FIRO process, James ex-
pects the U.S. Army Corps of Engineers
will obtain the data needed to update
its rules and regulations, allowing for
more flexible water management.
The same strategy is in effect at
Folsom Dam. It became a successful
FIRO project with the construction of
38
comstocksmag.com | May 2020
the auxiliary spillway, substantially
completed in 2017. The water control
manual, revised in June 2019, includes
operation rules that implement FIRO.
“For 12 years now, it has been
a long uphill battle,” says Michael
McMahon, a senior hydrometeorolo-
gist with HDR engineering in Denver,
who helped oversee FIRO projects at
Folsom Dam and at Lake Mendoci-
no. “The science of hydroforecasting
finally caught up with the need to
better and more efficiently operate
our reservoirs.”
The $900 million auxiliary spill-
way (also known as the Joint Feder-
al Project) is described on the U.S.
Bureau of Reclamation’s website as
including “a 1,100-foot-long approach
channel from Folsom Reservoir,
a concrete control structure with
six bulkhead and six radial gates, a
3,100-foot-long spillway chute, and a
stilling basin” that helps dissipate en-
ergy as water f lows out into the Ameri-
can River. This spillway is expected to
improve f lood management at Folsom
Reservoir, but FIRO implementation
in general “must be tailored on a
case-by-case basis to maximize water
Meteorologists say the
skill of their forecast has
improved by about one
day per decade. Twenty
years ago, the three-day
forecast had the accu-
racy of today’s five-day
forecast. Advanced tech-
nology has the potential
to make accurate weath-
er predictions more
than two weeks out.
Artificial intelligence
and machine learning
tools could be the key to
unlocking greater forecasting poten-
tial, says Jeanine Jones, interstate
resources manager of the California
Department of Water Resources.
The National Weather Service
bases predictions on dynamic models
using high-performance (and highly
expensive) supercomputers. With a
grid of the globe, they run various
simulations to see how a weather
pattern in one area might affect
another area. Before supercomputers,
researchers did statistical modeling.
This process, which uses statistics
based on historical data to project
outcomes, requires less computing
resources, which makes it cheaper.
Machine learning methods use al-
gorithms to examine huge amounts of
data to make improvements. In 2019,
DWR initiated a pilot with NASA to see
if new techniques, including machine
learning, can be used to improve and
extend forecasting capabilities. It is
still in progress. And it will take time
to evaluate the data.
“In weather forecasting, you
always have the possibility of getting
the right answer for completely the
wrong reasons,” Jones says.