The Mohave County ALERT Flood Warning System

1
The Mohave County ALERT Flood Warning System

• How the system works ..

Fred Weyermiller, Flood Warning Systems
Supervisor fred.weyermiller_at_co.mohave.az.us (928)
757-0925
2

• Mohave County currently manages 309 sensors
  located at 109 sites.
• These sites are located not only throughout
  Mohave County but also southern Utah, Yavapai
  County and the Hualapai Indian Reservation.

3

• Transmitters at these sites communicate the
  raw data utilizing 5 watt VHF radios to
  repeaters, which in turn forward or pass along
  the data to base collection stations.

Once the data reaches the base station it is
converted from its raw format into values that we
can relate to.
4

• Mohave County currently manages four base
  collection stations designed to collect raw
  weather data from the network. Two stations are
  maintained at the Public Works facility in
  Kingman. One station is the main server for the
  system and one is for diagnostic and testing
  purposes.
• Base collection stations are also located in
  the County Emergency Operations Center and the
  Public Works facility in Beaver Dam.
• Each base station is equipped with an antenna,
  data receiver and a data decoder which is
  connected to the computer.

5

• Each base collection station uses
  Environmental Data Acquisition and Database
  Management software to record and manage data
  from the field sensors.

6

• The server also monitors sensors for alarm
  threshold values such as heavy rainfall, stream
  flow and roadway surface ice.

7

• When pre-defined alarm thresholds are met, the
  server automatically dispatches these alarms to
  its recipients via cellular text messages and
  alpha-numeric pagers.
• Recipients of these alarms include Emergency
  Management personnel, Traffic Control personnel,
  Road Maintenance personnel, Sheriffs Office
  coordinators and dispatchers, Public Works
  Management personnel and Flood Control District
  personnel.

8

• Public Works responds to or investigates all
  alarms generated from the ALERT Flood Warning
  System.

9

• The 12 diameter waterproof standpipe houses
  all of the sensors and the data transmitter
  equipment.

10

• Sites like this one located near Mineral Park
  are designed to collect rainfall data only.
• This site is equipped with a 6dB gain
  directional antenna which improves the quality of
  the radio signal over longer distances.
• All of the sites are solar charged 12 VDC.

11

• Sites such as this one located along
  Interstate 40 _at_ Frees Wash measure both rainfall
  and stream flow.
• A low voltage (0-5V) submersible pressure
  transducer housed in a 2 inch diameter rigid pipe
  and anchored at the bottom of the wash sends
  information to the data transmitter.
• There are currently 40 sites in the network
  that monitor stream flow.

12

• Repeaters such as the Gold Road Crest site
  located near Oatman receive data from other sites
  and forward it to other repeaters. This allows
  the network to relay data from distances up to
  150 miles away. The network currently has nine
  repeaters.

13

• This map shows all of the repeaters in the
  Mohave County Network along with their
  communication paths
• The Hayden Peak repeater located south of
  Kingman at an elevation of 8,335 feet is the
  backbone of the network. All network data must
  pass through this repeater to reach the base
  station.

14

• The ALERT transmitter which is housed inside
  the standpipe collects information from the
  sensors and transmits the data to repeaters
  through the use of VHF radios.
• This particular transmitter is 12 VDC powered
  and capable of supporting up to 4 analog sensors.

15

• The tipping bucket is mounted to the top of
  the sites standpipe where rainfall is funneled
  into tipping mechanism. As the bucket tips, it
  causes a magnet to pass over a reed switch
  generating information to the transmitter. This
  particular bucket is calibrated to tip at 0.03937
  inch increments.

16

• Rainfall sensors are event driven meaning a
  transmission is generated for every tip of the
  tipping bucket.
• Analog sensors such as relative humidity,
  temperature, barometric pressure, road
  temperature, etc. generate reports on a change of
  0.25 or every 30 minutes, depending on their
  set-up.

17

• By continuing to develop and maintain the
  ALERT Flood Warning System, first responders can
  effectively and efficiently respond to disasters
  such as this one which occurred in Beaver Dam in
  2005.