Development of the Mohave County ALERT Flood Warning System

Each year, more deaths occur due to flooding than from any other severe weather related hazard. The main reason is people underestimate the force and the power of water. More than half of all flood related deaths result from vehicles being swept downstream. Of these, many are preventable. NOAA, National Weather Service.

In December of 2001, the Arizona Department of Water Resources (ADWR) installed seventeen weather gauge sites throughout portions of Mohave County. These locations included the Kingman area, Bullhead City area and the Golden Valley area. Included in this project was a repeater on Hayden Peak in the Hualapai Mountains and a repeater/precipitation gauge located on Gold Road Crest near Oatman. Additionally, one full weather station was installed in Kingman. A central base station which collects the raw data from the network was also installed at the Public Works facility located in Kingman.

In 2002, Mohave County installed a full weather station in the Hualapai Mountains. This new site also included the capability to monitor the road surface for wet, frost or frozen pavement conditions.

In 2003, the Mohave County Division of Emergency Management funded the upgrade of five sites to provide the capability to record and transmit wind data. Since these sensors have the ability to monitor wind direction and wind speed, this data can benefit emergency responders in the event of a hazardous materials incident or wild land fire. The network currently collects wind data from a total of nineteen different sites throughout Mohave County.

In 2003, Mohave County installed full weather stations in Dolan Springs and Mohave Valley as well as several precipitation and stream flow gauges (pressure transducers) throughout other areas that had been limited in coverage. In addition, a repeater/precipitation gauge was installed on Aubrey Peak and Mt. Tipton.

In 2004, Mohave County added several additional sites to the network including full weather stations in Beaver Dam, Colorado City, Wikieup and Lake Havasu City. Repeaters and precipitation gauges were also installed on Ram Peak north of Lake Havasu City and Scrub Peak in southern Utah.

In 2005, the Mohave County Division of Emergency Management coordinated a project that funded three repeater/precipitation sites that were installed on the Hualapai Indian Reservation.

In 2005, Mohave County added several additional sites to the network including full weather stations in Bullhead City, Meadview, Valle Vista, Audley Grade and Pinion Pines. The Pinion Pines and Audley Grade sites also included the capability to monitor the road surface for wet, frost or frozen pavement conditions. Additionally, base stations were installed in Beaver Dam, the Mohave County Emergency Operations Center (EOC) in Kingman and at the Arizona Department of Transportation Office located in Kingman. These additional base stations will enhance access to real-time data monitoring in the event of weather related emergencies.

In 2006, Mohave County installed eleven new weather system sites including a repeater/precipitation station on the Arizona Strip northwest of Mt. Trumbull (Craigs Knoll). This new site was added to reduce the 137 mile distance the data was required to travel from the Scrub Peak, Utah repeater to the Hayden Peak repeater. The Craigs Knoll repeater will improve the quality of the data received from the Colorado City, Beaver Dam and Moccasin areas.

In 2007, Mohave County installed twenty-six new weather system sites including four new sites in north Golden Valley to enhance the Sacramento Valley network. Three new precipitation gauges were installed in the Diamond Bar/Grapevine Canyon area to provide an early warning network for this area due to the additional traffic generated from Grand Canyon West and the potential for flash flooding in this area. Four new precipitation gauges including two with stream flow monitoring capabilities were installed in the Bullhead City/Mohave Valley area to compliment the existing area network. Additionally, a precipitation and stream flow gauge was installed in the community of Moccasin on the Moccasin Wash to monitor activity at this location which has a history of flood related damage. Mohave County also partnered with the Arizona Department of Transportation to install precipitation and road surface sensors at Hillside and Peach Springs to monitor road surface temperature and surface moisture activity. In addition to the automated gauges installed in 2007, real-time weather monitoring cameras were installed in the Hualapai Mountains southeast of Kingman and in the community of Beaver Dam near the Utah border. The Hualapai Mountain camera monitors road surface conditions along Hualapai Mountain Road at an elevation of 6,093 feet. The camera located in Beaver Dam monitors activity along the Beaver Dam Wash and the Virgin River.

In 2008, Mohave County installed ten new weather system sites which included the completion of the Beaver Dam Watershed network. As a result of a significant flood event which occurred in the community of Beaver Dam in January of 2005, seven new gauges were identified for installation in the watershed which encompasses portions of Washington County, Utah and Lincoln County, Nevada. Of these seven new installations, three of the sites are capable of monitoring stream flow upstream of the community. Additionally, during the 2008 year, Mohave County partnered with the Arizona Game & Fish Department to install gauges in the Virgin Mountains and in the Potts Mountain area north of Alamo Lake. In addition to rain gauges, these installations included sensors which provide the ability to remotely monitor the depth of the wildlife water tanks managed by the AZGFD. Funding for these two projects was provided courtesy of the Wild Sheep Foundation.

In 2009, Mohave County installed eleven new weather system sites which included six in the Big Sandy Basin. Two of these sites located in the upper portion of the basin have the ability to monitor stream flow activity. Additionally, one new rain gauge was installed in the Kingman area at the head of the Diagonal Wash sub-basin and one new rain gauge was installed in the Virgin River Basin along State Route 389, near Moccasin. In addition, one new rain gauge was installed in Mohave Valley approximately five miles east of State Route 95 to enhance early warning for events similar to the September 4, 2009 event that impacted the Tierra Del Rio Sub-division. New repeaters were installed at Senator Mountain, Mt Perkins and Grand Canyon West. The Senator Mountain Repeater which is located north of White Hills will improve the radio telemetry between the Meadview/White Hills area sensors and the Hayden Peak Repeater. The Grand Canyon West Repeater will improve the quality of data from sensors along Diamond Bar Road and the Mt Perkins Repeater will improve the quality of data from sensors along the Colorado River between Hoover Dam and Bullhead City. In addition, Mohave County partnered with the Arizona Game & Fish Department to install the Tufa site located in the Black Mountains north of Cottonwood Road. This site has the ability to remotely monitor both rainfall and the depth of the wildlife water tank managed by the AZGFD. In addition to the automated gauges and repeaters installed in 2009, a real-time monitoring camera was installed in Golden Valley to monitor activities along the upper portion of the Sacramento Wash.

In 2010, Mohave County installed eight new weather system sites which included two precipitation gauges in the Hualapai Valley Basin, two precipitation gauges in the Kanab Plateau Basin, one precipitation gauge in the Sacramento Valley Basin, one stream flow sensor in the Lake Havasu Basin and two precipitation/stream flow sensors in the Lake Mohave Basin. The two new sites in the Lake Mohave Basin were located north and east of Bullhead City to provide early warning for the Laughlin/Bullhead International Airport.

In 2011, Mohave County installed ten new weather system sites which included two in the Lake Havasu Basin, two in the Lake Mohave Basin and one in the Sacramento Valley Basin. The new gauge in the Sacramento Valley Basin is capable of measuring stream flow along the Sacramento Wash, and was placed approximately nineteen miles upstream of Oatman Highway to provide early warning for the low water crossing south of Golden Shores. Five of the new gauge installations were placed on ridgelines along various mountain ranges to provide precipitation data for multiple drainage basins. In addition to the automated gauges installed in 2011, real-time weather monitoring cameras were installed on the Highland Wash in Bullhead City and the Sacramento Wash south of Golden Shores.

In 2012, Mohave County installed eight new weather system sites including one in the Lake Mohave Basin that is designed to monitor the water depth of a rapid infiltration basin. Four of the new gauge installations were placed on ridgelines along various mountain ranges to provide precipitation data for multiple drainage basins. In addition to the automated gauges installed in 2012, real-time weather monitoring cameras were installed in Horizon 6, near Lake Havasu City and at Antelope Drain, south of Bullhead City near the Desert Lakes Golf Course.

In 2013, Mohave County installed fourteen new weather system sites including two in the 5,400 Acre Dean Peak Burn Scar, southeast of Kingman. One new repeater was installed in the Dolan Springs area (Table Mountain Plateau) to enhance communication coverage throughout this area. In addition, three stream flow measuring stations were installed in south central Golden Valley where the Thirteenmile Wash joins two branches of the Sacramento Wash. In the Lake Havasu City area, a stream flow measuring station was installed in the newly constructed Horizon 6 Detention Basins to provide early flood warning for the Horizon 6 community and Mockingbird Wash.

In 2014, Mohave County installed sixteen new weather system sites including five in the Upper Sacramento Wash Basin in north Golden Valley. One new station was installed near the community of Golden Shores in the lower portion of the 1,330 square mile Sacramento Wash Basin. Two new stations were installed along the newly constructed Diamond Bar Road to enhance flood warning for the motorists traveling to Grand Canyon West and two new stations were installed near Lake Havasu City.

Presently, the Mohave County ALERT (Automated Local Evaluation in Real Time) Flood Warning System Network consists of one hundred and seventy-two fully automated sites including twelve repeaters and fourteen full weather stations. One hundred and fifty-nine sites have the capability of receiving and reporting precipitation data in .04" increments. Six of the sites in the network monitor road surface temperature and road surface moisture (conductivity). Sixty-one sites have the ability to report stream flow data by use of a pressure transducer (Stream Gauge PT) which is installed in the bottom of the dry wash or stream bed. This device senses the pressure exerted from the water surrounding it and instantaneously transmits the information to the base station. The stream and precipitation gauges are "event driven", meaning they report in real-time or immediately as the data is collected at the site. Five of the sites have the ability to measure the stormwater depth of constructed infiltration basins by use of a pressure transducer (Depth Gauge PT). All of the full weather stations update their sensor data on a timed basis, typically every thirty minutes. The primary funding for the continued growth of the ALERT System has come from the Flood Control District and from the Highway User Revenue Funds (HURF).

The central base station which receives all of the data in "real-time" from the network uses DataWise software which was developed by DEC DataSystems. This software provides the ability to collect and manage weather related raw data values from all of the sites within the network. This data is used to assess potential flooding threats throughout Mohave County and trigger a response from emergency personnel. Pre-set alarm values are defined in the software that when met, provide notification to personnel via alpha pagers and cellular phones. Recipients of these alarms include the Flood Control District, Emergency Management, Sheriffs Office and various administrative personnel within Public Works and Development Services.


Beaver Dam Flood, January 2005

All of the data that is collected throughout the Mohave County network is uploaded through the internet in real-time and also transmitted to the National Weather Service Office in Las Vegas, Nevada from the Hayden Peak Repeater on a frequency of 169.425 MHz. This data provides the Weather Service with the ability to compare actual ground conditions with those observed on radar, thus enhancing the ability to issue weather watches and warnings. In addition, data is forwarded to the Arizona Department of Water Resources on five minute intervals as part of the statewide Flood Warning System Network.

The Mohave County ALERT Flood Warning System network is maintained by the Flood Control District under the direction and authority of Nicholas Hont, P.E., Flood Control District Chief Engineer.