System monitors flood-prone creeks
- By Eric Kulisch
- Mar 04, 2001
Creek Level Monitor
When rain is forecast in Palo Alto, Calif., city workers and residents may
turn to a new Web site to learn how fast their creeks are rising.
The Creek Level Monitor is a welcome warning tool for people who still vividly remember when the
San Francisquito, Matadero and Adobe creeks overflowed their banks in 1998,
said John Ballard, who supervises the storm drain system for the city's
Department of Public Works.
At that time, police officers and other emergency personnel had to scramble
to bridges to check gauges and radio in the readings about every 20 minutes.
Now the Web-based system has become an integral part of emergency management
"Local residents watch this very religiously," Ballard said. "We created
it so residents can get this information themselves."
After the 1998 flood, Palo Alto Public Works installed ultrasonic devices
on bridges and wired them to adjacent storm pump stations to provide remote
water-level measurements. The data is transferred by an existing communications
system that controls the pumps and is then made available online.
The dynamic creek monitor graphically represents the creek beds at five
bridge locations. Water levels are shown in blue. An accompanying line graph
shows creek, tide and flood basin levels for the preceding 12 hours. Other
data includes 24-hour and annual rainfall totals. There's even a Creek Cam
at a bridge over West Bayshore Road.
The system also helps park rangers remotely monitor and maintain water levels
in the flood basin, which serves as a wildlife and bird sanctuary. Using
electric gates on a man-made levy, the rangers periodically allow water
from the San Francisco Bay to flush the ecosystem to keep it from drying
Many agencies and flood districts have flood prediction Web sites relying
on historical data, but Ballard said he knows of no one else that provides
current information. The Creek Level Monitor is updated every three minutes.
Future plans call for the system to integrate data from rain gauges
in the regional watershed to help predict creek levels before they reach
critical levels, Ballard said.