Flood — Northern Washoe, Nevada

1997-01-01 to 1997-01-17 · Northern Washoe, Nevada

Wider weather episode

The floods of January l997 were caused by several factors. First, the Sierra and western Nevada had experienced two above normal precipitation years (1995, 1996). Second, a major winter storm December 21st and 22nd 1996 deposited heavy snow in the Sierra and western Nevada. Four to six feet of snow was common below 7000 feet in the Sierra with up to eight feet at the higher elevations. One to three feet of snow was found across the valleys of western Nevada. The following week into New Years' Day showed a dramatic change in the weather pattern. Copious amounts of moisture and warm air were transported from the subtropics into the Sierra and western Nevada. The heaviest rainfall occurred Janaury lst and 2nd, and snow levels were as high as 11,700 feet on the 1st.An incredible amount of rainfall and snowmelt runoff poured out of the Sierra Nevada from December 30, 1996 to January 6, 1997. For example, an estimated 25 inches of rain and snowmelt runoff occurred during the period on the Squaw Creek Basin (in the upper Truckee River Basin in Placer County, California) during this period. This scenario was typical throughout the region and resulted in extensive flooding on the Truckee, Carson, Walker, and Susan Rivers. Record flooding occurred on much of the Truckee, Carson, and Walker Basins. This flooding caused tremendous amounts of public and private damage throughout the eastern Sierra and extreme western Nevada.A winter storm on January 22nd again dropped heavy amounts of snow in the Sierra and the valleys of western Nevada but not as much as the December storm. This storm was followed by another significant storm January 24th through the 26th which aggravated flooding along the Truckee and Carson Rivers. However, this storm system was much colder than the New Years' storm. Snow levels were around 6500-7000 feet in the Sierra and western Nevada, minimizing the amount of snowmelt from the higher elevations. Thus, river stages were much lower than the New Years' flooding. The main result was urban and small stream flooding.The following information provides details of damages, deaths, and injuries caused by flooding in the Reno County Warning Forecast Area (CWFA). The CWFA includes parts of the eastern Sierra and western Nevada.NVZ005-CAZ070 Northern Washoe County Nevada and Surprise Valley CaliforniaThere were no reports of damage in Northern Washoe County Nevada. However, parts of Surprise Valley California were inundated by heavy rainfall, causing mud and debris from mountain and hill sides to slide into homes in the community of Lake City (north of Cedarville). Also, parts of County Road One were either covered by mud or washed out. Estimated damage to the road was about $1.5 million. Estimated damage to area homes was about $500,000.CAZ071 Lassen...Eastern Plumas...and Eastern Sierra CountiesThe greatest damage due to flooding occurred in Plumas County. $90,000 in damage was done in the city of Portola alone. The most extensive damage was to homes, bridges, and roadways. Flooding and rain caused a 50 foot section of Highway 70 to crumble between Blairsden and Sloat. There was also extensive damage to railroad infrastructure. Damage amounts were as follows: 1) public facilities $60 million, 2) private owners and businesses $10 million (50 homes reported damage), and 3) Federal Highway System $21.2 million (which includes severe damage to Highway 70). For Lassen County, damage amounts were as follows: 1) public facilites not available, 2) private owners and businesses $500,000, and 3) Federal Highway System $1 million. Finally, there was one injury reported in Sierra County. Sierra County estimated damage to private owners, businesses, and public facilities at $2 million. The Federal Highway System destruction was near $25.6 million (incudes damage to Highway 49).NVZ002-CAZ072 The Greater Lake Tahoe AreaThe Greater Lake Tahoe experienced extensive damage due to flooding rivers, streams, and mudslides. There was so much rain and melted snow that Lake Tahoe was pushed over its legal limit by 3.5 inches, reaching an altitude of 6,229.39 feet on January 5th. This was the highest elevation of the lake since July 17, 1917. Each county that lies within this zone is examined below:Placer County: Flooding in this county eroded away mountain sides which broke sewer and power lines. Serious damage occurred at Squaw Valley Lodge, a separately owned facility behind the Squaw Valley Ski Area main entrance. The south fork of Squaw Creek jumped its bank and burst through the lodge. This destroyed many units in the lodge as well as depositing thick mud. Many public roads, bridges, and other infrastructure were affected by the floods, especially along the Truckee River. All bridges across Highway 89 were destroyed or severely damaged. Damage estimates for public property was near $11 million. 137 homes and 22 businesses were damaged. Total damage to private homes, businesses, agricultural losses, and private roads was near $10 million. Destruction to the Federal Highway System was near $7.7 million which includes widespread damage to Highway 89.Nevada County: Property along the Truckee River, Donner Creek, and Trout Creek was severely damaged. On the Truckee River, two small bridges were ripped out and several others were under water. Mudslides closed several major roads and Union Pacific railroad tracks. Estimated damage to public facilities was $5 million. 100 homes and 40 businesses were damaged, costing an estimated $20 million. Federal Highway System damage was about $3.9 million.El Dorado County: The Upper Truckee River reached its highest level ever on January 2nd. The National Weather Service does not have a flood stage here, and there is no telemetry on the gage. The American River west of Echo Summit tore away a number of bridges that provided access to summer homes. U.S. Highway 50 received extensive damage from water undermining sections and also from mud slides. One injury was reported when a boulder dislodged by a saturated hillside slammed into a truck. A 43 year old woman received serious head injuries. Estimated damage in El Dorado County was as follows: 1) public facilites $17 million, 2) private owners and businesses $5 million, and 3) Federal Highway System $40.5 million. This incudes severe damage to U.S. Highway 50. Most of the damage was not in the Reno CWFA.Alpine County: The most damage in this county was to the Federal Highway System which was estimated at $5.5 million. Public damage was projected to be near $400,000.The following shows selected crests at certain sites along the Truckee River in Placer and Nevada Counties and the east and west forks of the Carson River in Alpine County:River/Location Flood State Maximum Crest (feet) and DateTruckee River near 4.5 ft 9.97 ft (11,900 cfs) on Truckee, CA 1/2/97*. The United States Geological Survey (USGS) estimated this to be a new record stage/flow here. USGS estimated this to be greater than a 100-year flood at this location.Truckee River at 11.0 ft 13.17 ft (14,800 cfs) onFarad, CA 1/2/97. This was short of the record stage of 14.50 feet (17,500 cfs) set 11/21/50. This was estimated by the USGS to be less than a 50 year flood.East Fork Carson 7.0 ft* 11.78 ft (21,000 cfs) onRiver near 1/2/97. This was a newMarkleeville, CA record stage/flow for this location. This was estimated by the USGS to be greater than a 100 year flood.West Fork Carson 6.0 ft Estimated greater thanRiver at Woodsfords, 11.0 ft (8,000 cfs) sinceCA river diverted away from gage on 1/2/97. This was a new record stage/flow here. This was estimated by the USGS to be greater than a 100 year flood.*Telemetry inoperative or unreliable during most of the flood event.NVZ001-003-004 MINERAL AND SOUTHERN LYON COUNTIES...THE GREATER RENO-CARSON CITY-MINDEN AREA...WESTERN NEVADA BASIN AND RANGEFlood devastation was widespread across western Nevada. Most of the damage occurred from the Truckee, Carson, and Walker Rivers early in January. As reported by the American Red Cross, two deaths and at least 50 injuries occurred in western Nevada (four of the injuries required hospitalization). The Truckee and Carson Rivers crested above flood stage again later in the month (Janaury 25th and 26th), but the flooding was much less than the record flooding at the beginning of the month. Each county within Nevada zones one, three, and four is analyzed below:Mineral County: Only minor damage occurred here. Estimated cost was $2,400.Pershing County: No damage was reported here as the flooding rivers mentioned above do not flow into this county.Churchill County: Damage to the public facilities (including public buildings, utilities, and roads) was about $30,000. Total private damage was estimated at $315,000 of which $267,000 was to the Truckee-Carson Irrigation District facilties.Carson City: The mainstem Carson river in combination with swollen creeks and streams flowing from the eastern Sierra caused extensive damage in the Carson City area. The heavy rains of January 1st and 2nd deluged parts of Carson City, forcing the closure of roads and businesses. Damage to public facilities was about $6.4 million. Damage to homes and businesses was not available at the time of this documentation.Storey County: There was damage done to public and private property in Storey County, both on the mainstem Truckee and on small streams. Estimated public damage was about $2 million. This includes the destruction of five bridges on the Truckee, two miles of levees, and Six Mile Canyon Road. Damage to private owners and businesses was about $1 million. This includes $500,000 to the Mustang Ranch and $125,000 to three homes.Lyon County: Widespread devastation occurred in the towns of Dayton (from the Carson River), Wellington and Smith (from the West Walker River), and Yerington (from the mainstem Walker River). The greatest destruction was inflicted on the town of Yerington. Over 250 homes received extensive damage from flood waters. Estimated damage for private property in Yerington alone was near $15 million. Over 30 homes were damaged in the Wellington and Smith areas, bringing damage estimates here to $1.5 million. Damage to public facilities in the county was over $3 million. Parts of Highway 208 and 339 in the Wilson Canyon area were completely washed away. Damage to agricultural land was widespread, but losses will not be known for some time.Douglas County: The raging Carson River caused massive destruction to homes and levees. Over 75 homes in the Minden/Gardnerville area were known to receive damage estimated at $5 million. Public damage, especially to the Carson Valley levee and irrigation system, will likely exceed $50 million. U.S. Highway 395 and Highway 88 were inundated with water, isolating residents in the Minden/Gardnerville area for several days. There was one death attributed to the flooding in Gardnerville. A 59 year old man was swept into the East Carson River while operating a front-end loader near its banks.Washoe County: Devastation was immense in this county due to the concentration of businesses and homes along the Truckee River. Estimated damage to 1,420 businesses and homes in the city of Reno was near $200 million. Four major casinos had to close during the climax of the flood, including the Reno Hilton which received $15 million in damage (a part of the total $200 million calculated for the city). Parks and recreational facilities along the Truckee River in Washoe County were either damaged or ruined, costing about $3.2 million. The Reno-Tahoe International Airport also took a heavy blow from flooding. Runways and parts of the terminal building were submerged in water. Consequently, there was extensive damage to the east-west runway and the terminal building. Cost to repair the airport was calculated near $32 million. Sparks, just east of Reno, was also devastated. The Sparks industrial park was flooded by the Truckee River. In some parts of the industrial area, standing water reached as high as six feet. Damage to homes and businesses in the city of Sparks was estimated near $300 million. One death occurred in Sparks. A 53 year old man was believed to have been swept into the Truckee River. He apparently went to his place of business in order to retrieve some personal belongings. The road to his business was washed away, and it was surmised that he and his truck were swept into the Truckee River.In addition to the homes and businesses damaged, roads in Washoe County were also affected by erosion and mudslides. Three mudslides closed Highway 43l (Mt. Rose Highway) between the Mt. Rose Ski area and the 8,9ll foot summit for several days. Interstate 80 near the California border was smothered by a mudslide, closing the area to commuters for a period of time on January 2nd. A part of the westbound lane of Interstate 80 in Sparks was closed for several days when flood waters eroded the south wall of the nearby Helm's Gravel Pit. Heavy flooding on the south side of the interstate forced water to flow in the opposite direction and into the Helm's Gravel Pit, eroding the banks of the pit to a depth exceeding one hundred feet. This caused the nearby westbound lane to collapse. Cost to repair the interstate was near $2.5 million. Finally, U.S. Highway 395 in Washoe Valley was covered by water for two days, closing the main link between Reno and Carson City. Total damage to the Federal Highway System in Washoe County alone was about $5 million. Overall damage to the Federal Highway System in the state of Nevada was estimated over $13 million.The following shows selected crests along the Truckee, Carson, and Walker Rivers in western Nevada:River/Location Flood Stage Maximum Crest (feet) and DateTruckee River at 12.0 ft Estimated at 14.94 ft Reno, NV (18,200 cfs) on 1/2/97. This was short of the record flow of 20,800 cfs set 12/23/55. This was estimated by the USGS to be less than a 50 year flood.Truckee River at 11.5 ft Estimated over 17.5 ft Sparks, NV (over 19,000 cfs). This was a new record stage/ flow for this location.Truckee River at 14.0 ft 24.04 ft (flow unknown)Vista, NV on 1/2/97 which was a new record stage/flow for this location.Truckee River at 10.0 ft 16.08 ft (22,000 cfs) onNixon, NV l/3/97 which was a new record stage/flow for this location.East Carson River 7.0 ft Estimated at 12.8 ftnear Gardnerville, NV (20,000 cfs) on 1/2/97 which was a new record stage/flow for this location. This was estimated by the USGS as a greater than 100 year flood.Mainstem Carson 10.0 ft 18.4 ft (27,500 cfs) onRiver near Carson l/3/97 which was a newCity, NV record stage/flow. This was a 100 year flood by the USGS estimates.Mainstem Carson 10.0 ft Estimated at 15.2 ftRiver near Fort (25,000 cfs) on 1/3/97Churchill, NV which was a new record stage/flow. The USGS estimated this a greater than 100 year flood.West Walker River 8.0 ft Estimated at 13.6 ftnear Wellington,NV (5,800 cfs) on 1/3/97 which was a new record stage/ flow. The USGS estimated this as a greater than 100 year flood.Mainstem Walker River 11.3 ft 14.47 ft (flow unknown)at Yerington, NV on 1/4/97 which was a new record stage/flow.CAZ073 MONO COUNTY CALIFORNIAThe floods of January l997 did not spare Mono County. Heavy rains with high snow levels produced disastrous results. For example, the town of Mammoth Lakes reported about eight inches of rain in a 36 hour period (January lst and 2nd). This same intensity was common across the eastern Sierra in Mono County, causing a rapid rise to rivers, creeks, and streams. In fact, the West Walker River became a powerful torrent of water which caused massive destruction. Damage from flooding was found in the towns of Mammoth Lakes, Coleville, Walker, and Topaz. 111 homes and 4 businesses were destroyed by the floods, totaling at least $25 million in damage. Destruction to public facilities (including national monuments) was near $5 million. Above all, extensive damage was done to the Federal Highway System. In fact, a 12 mile stretch of U.S. Highway 395 (roughly between Topaz and Sonora Junction at Highway 108) was completely destroyed by the West Walker River. The cost for repairs was estimated at $20 million. Total damage to the Federal Highway System in the county was near $48 million.The following shows river information near Coleville, California for the West Walker River:River/Location Flood Stage Maximum Stage and CrestWest Walker below 5.5 ft 10.06 ft (11,700 cfs) onLittle Walker near 1/2/97 was a recordColeville, CA stage/flow. The USGS estimated this to be a greater than 100 year flood West Walker near 7.0 ft 9.12 ft was the highest Coleville, CA stage recorded before the gage was washed away on 1/2/97. Crest was estimated over 12 feet. This was considered a greater than 100 year flood.

Source: NOAA Storm Events Database, event_id 5590160. Narrative written by the NWS forecast office that issued the report.