| DAMAGING FLOODS |
| Location | Start Date | Information |
|---|
| Cheyenne, Crow Creek, Dry Creek | 15-Jul-1896 | Heavy rain (4,78 inches in 3 hours) caused flooding resulting in extensive damage to buildings, transportation facilities, and utilities. There was loss of lives. |
| Cheyenne, Crow Creek | 20-May-1904 | A 500-year flood from heavy rain created a 20-25 foot wall of water down Crow Creek. Damage to buildings, transportation facilities, utilities, bridges and houses washed from foundations; large numbers of people caught in houses. There was 1.10 inches of rain in one hour and estimated discharge of 7000 CFS. Two children Killed. |
| Cheyenne, Crow Creek | 23-Apr-1929 | A 500-year flood was caused by heavy rain producing 3.20 inches in 24 hours. The flood damaged buildings, transportation facilities, and utilities. The event resulted in one death. The Creek had a discharge of 8,000 CFS. |
| Cheyenne, Crow Creek | 1-Jun-1929 | Flooding was produced by showers near headwaters, ground saturation, and tributaries full of melting snow (WEMA Interagency Hazard Mitigation Report). Flooding was also caused by rainfall combined with snowmelt runoff (Wyoming Floods and Droughts, National Weather Summary 1988-89). The flooding led to bridges, dams, highways, crops, and railroads being damaged at a cost of an estimated $500,000. There was one death because the individual did not hear warnings to evacuate the area. According to FEMA Flood Insurance Study March 2,1994 it was a 500-year flood and the Creek had a discharge of 8,000 CFS. |
| Dry Creek Basin | 26-Aug-1949 | A severe storm producing 1 inch of rain in 10 minutes led to widespread street and basement flooding at an estimated cost of $100,000 |
| Cheyenne, Dry Creek, Crow Creek | 15-Jun-1955 | Heavy rain causing flooding washed out railroad tracks, flooded parts of the city, basements, streets crumbled, estimated cost $105,000 according to WEMA Laramie Boomerang and NOAA. Also, according to them 2.4 inches of rain fell. According to FEMA Flood Insurance Study March 2, 1995 Dry Creek had a discharge of 5,800 CFS. |
| Cheyenne | 22-Jul-1966 | Heavy rains up to 2 inches with hail measuring up to 3/4 inch caused flash flooding. Damage mostly in the central and eastern portion of Cheyenne. |
| Meriden | 9-Aug-1966 | Heavy rain with some small hail did damage to drops and caused some flash flooding with small bridges destroyed. |
| Cheyenne | 19-Jul-1973 | On the 19th, Cheyenne and part of Laramie County received heavy rains resulting in swollen creeks and flooded basements. For Cheyenne, it was the second greatest 24-hour rainfall on record and totaled 3.42 inches. The rains occurred over much of the state but seemed heaviest over the southeast corner. |
| Cheyenne | 8-Sep-1973 | A nearly 3 inches downpour of rain with small hail caused flash flooding mainly in downtown Cheyenne. Hail caused damage to trees, shrubs and flowers. |
| Cheyenne | 23-May-1982 | Brief heavy rains from 1.43 inches at the Weather office to 2.8 inches on the east side of the city combined with soft hail caused local flooding and evacuation of several homes. |
| Cheyenne, Crow Creek | 22-Jul-1983 | Heavy rain amounting to 3 inches caused a flood where a mobile home park was evacuated and ranches, bridges, roads, and an irrigation system had damage. Estimated damage to bridges was $25,000. The flooding made a new channel and basements flooded. |
| Southeast corner | 22-Jul-1984 | Golf ball-sized hail, wind gusts to 80 MPH and very heavy rain hit area a few miles west of Wheatland in Platte County. Couple houses had 4 to 5 feet of water in them. Severe thunderstorm with golf ball-sized hail in Burns and Hillsdale area of east Laramie County did over $500,000 damage to crops, vehicles, and buildings. |
| Albin | 31-Jul-1985 | Five inches of rain and marble sized hail fell at Albin. Basements were flooded and there was extensive flooding of low-lying areas. |
| Cheyenne, Crow Creek, Dry Creek | 1-Aug-1985 | A nearly stationary severe thunderstorm, or storms, produced the most damaging flash flood on record Cheyenne and the State. Twelve people lost their lives, 70 were injured; and damage to homes, cars and businesses were estimated at $65 million, $61.1 million (Wyoming Floods and Droughts, National Weather Summary 1988-89), and $40 million (WEMA). At the NWS Forecast Office near the airport, 6.06 inches of rain fell in just over 3 hours; 3.5 inches fell between 1900 and 2000 MST. Elsewhere in and around Cheyenne, rainfall from the storm totaled between 2 and 6 inches. Around 1900 MST cars and trucks were reported floating down Dry Creek in northwest Cheyenne. By 1930MST, in addition to blinding rain, hail up to 2 inches in diameter and winds to 70 mph were occurring in the area. Flood waters were at their height from 1900 to 2200 MST. Dry Creek became a raging torrent through north Cheyenne. Ten of the twelve deaths occurred along Dry Creek when people were swept away in their cars as they tried to cross flooded streets. A Sheriff's Deputy and the child he was trying to rescue from a stranded vehicle were swept away. Many streets turned into 2 to 4 foot deep rivers with large amounts of hail floating on top. Basements of homes and businesses quickly filled up with water and hail as flood waters crashed through doors and windows. One man suffered a heart attack and died while bailing out water from his basement. An elderly woman, who had taken shelter in her basement due to an earlier tornado warning, became trapped in her basement when the flood waters came crashing through basement windows and filled to the ceiling. Funnel clouds were observed 5 and 3 miles southwest of the Weather Service Office at 1824 and 1841 MST, respectively. Some basements equipped with drains were still flooded with 2 to 5 feet of hail after the water drained away. In some low-lying areas of Cheyenne the hail had piled up by flood waters into 4-to 8-foot drifts. Estimated peak discharge at Dry Creek location 5100 CFS (WEMA) and 5,880 CFS (FEMA Flood Insurance Study March 2,1994). Estimated peak discharge at Crow Creek 8,000 CFS (FEMA Flood Insurance Study March 2,1994) |
| 25W Cheyenne | 17-May-1987 | A thunderstorm developed over the west section of Laramie County during the morning. This thunderstorm marched through Laramie County with locally heavy rain and hail. Rains of over an inch were reported west and north of Cheyenne with 0.82 inches of rain reported at the Cheyenne airport. Water got as deep as 3 to 4 feet in areas of Cheyenne. This flooded some parked cars and made a few roads temporarily impassable. Numerous reports of 0.25 to 0.75 inch diameter hail were noted around Cheyenne. Drifts of hail 6 to 8 inches deep were observed about 1.5 miles north of the airport. |
| Pine Bluffs | 29-Jul-1990 | A thunderstorm produced 3 to 4 inches of rain in the Pine Bluffs area between 1500 and 1600 MST. Minor flooding of streets occurred in the city, with some basements flooded. |
| Pine Bluffs | 29-Jul-1990 | A thunderstorm produced 3 to 4 inches of rain in the Pine Bluffs area between 1500 and 1600 MST. Minor flooding of streets occurred in the city, with some basements flooded. |
| Near Cheyenne | 12-Jul-1991 | Heavy rains with thunderstorms brought 1.70 inches of rain 4 miles west of Cheyenne and 1.95 inches of rain 3 miles north of the airport. Street and some basement flooding was reported in Cheyenne. |
| 3 W Cheyenne | 22-Jul-1991 | A thunderstorm brought 0.56 inch of rain in 45 minutes with some street and basement flooding. |
| (CYS) Cheyenne Arpt | 13-Aug-1994 | A thunderstorm moved north out of Colorado into southwest Laramie County. This storm produced flash flooding in a few small streams in extreme southwest Laramie county, washing out a couple of roads. Rainfall totaled 3.26 inches in an hour and 0.65 inches in 10 minutes. |
| Cheyenne | 31-Jul-1996 | Heavy rain caused by thunderstorms caused urban flooding in Cheyenne. |
| 8 NE Cheyenne | 15-Aug-1996 | Heavy rainfall from thunderstorms caused some flooding of creeks in the area. |
| Cheyenne | 29-Aug-1996 | Heavy rainfall from thunderstorms caused flooding in and near Cheyenne. Some roads had up to a foot of water on them and some intersections were closed for a time. Some basements in the north part of town became flooded. |
| Cheyenne | 16-Aug-1997 | Two to 3 feet of water flooded intersections in southern Cheyenne. |
| 9 ESE Cheyenne to 12 SE Cheyenne | 9-Jul-1998 | A thunderstorm produced rainfall amounts of up to 3.5 inches, 9 miles east of Cheyenne. Water was flowing over Campstool Road, which runs along Crow Creek. |
| Laramie Range - Cheyenne Foothills | 29-Apr-1999 | Minor flooding occurred in parts of the Laramie range into the Cheyenne foothills as a result of snowmelt and around 2 inches of rainfall. Flooding was reported along parts of Crow Creek in south Cheyenne with other minor flooding reported along Lodgepole Creek northwest of Cheyenne. |
| West Portion | 15-Aug-2000 | Heavy rains fell over parts of Laramie county west of Cheyenne, with estimates of 4 to 6 inches over an area southwest of Federal, WY. Some flooding was reported on Happy Jack Road, with parts of County Road 109 washed out. |
| 5 S Cheyenne | 30-Jun-2004 | Heavy rain fell over Orchard Valley resulting in flooding of low-lying areas. U.S. Highway 85 was closed for a time just south of Cheyenne, WY due to flooding. |
| NON-DAMAGING FLOODS |
| 5 E Cheyenne to Burns | 9-Jul-1998 | A thunderstorm dropped up to 3.5 inches of rain on Lodgepole Creek, 5 miles east of Cheyenne. Minor flooding occurred along the creek betweeen Cheyenne and Burns. |
| Carpenter | 3-Jun-2005 | Water up to a foot deep covered roads in and near Carpenter, WY. |
