Areal flooding developed along the Cache La Poudre and South Platte River Basins as a combination of heavy rainfall and spring runoff unundated the region.  The Cache La Poudre reached flood stage from the 10th the the 14th.  The South Platte rose above flood stage at Kersey from the 9th to the 15th.  A few landslides were initially reported along the Saint Vrain River with minor flooding south of Bohn Park in Lyons. Minor flooding also produced mudslides in Boulder County.  In Jefferson County, South Turkey Creek Rd was washed out in several places.  Mandatory evacuations were ordered at the St. Vrain Campground in Weld County along with numerous roads closures across southern, central and eastern portions of Weld County.   The hardest hit areas included: Elbert County, along Bijou Creek;  eastern portions Adams and Arapahoe Counties;  and Morgan County, where 3 to 5 inches of rain had fallen  Kiowa Creek, Bijou Creek, Antelope Creek and Rock Creek were all running at full capacity and in most cases widespread breaching took place along those creeks. Both the Kiowa and Bijou Creeks entered into the South Platte just west of the City of Fort Morgan and contributed to higher water levels in the South Platte which was already running high from waters coming down the South Platte from the front range rainfall and spring runoff from the mountain snow melt.   Antelope Creek which enters Morgan County from Adams County was  running over capacity and caused heavy damage and dangerous conditions in the southwest portion of the county.   These conditions caused the closure of CO 52 south of Wiggins to Hudson due to water running over the highway and in some cases through the highway.  Morgan County authorities issued pre-evacuation alerts.
The floods and heavy rainfall created damage over large portions of Morgan County. Approximately 26 square miles of Morgan County���s 36 square miles experiences some degree of road damage and road closures.  The combination of saturating rains on the 8th and 9th produced more runoff than the creeks and drainages could handle. Flooding due to rain water started to move east through Morgan County washing over county roads, both dirt and pavement.  The southwest and northeast portions of the county were greatly affected and the majority of roads in these areas we impassable by vehicle due to water either running over the roads or water cutting trenches through the road.  Swift-flowing water swept an ambulance, and its passengers, into rain-swollen  Antelope Creek in Morgan County early on the 10th. The Byers Fire and Rescue ambulance was attempting to rendezvous with the Morgan County Ambulance service to transfer a patient when it was carried into the normally dry creek. The Byers ambulance attempting to cross an intersection at Morgan County Roads 4 and D. They went through water that was a little too swift and a little too high and were swept off the road. Fast water carried the ambulance , with the patient, one passenger and three firefighters, about 100 yards downstream. Everybody was able to make it out of the vehicle with no injuries due to the accident. The patient was able to walk, and the group traveled about a mile through the snow by foot to reach the Morgan County and Wiggins Rural Fire ambulances. The vehicle remained caught on a bank in up to 8 feet of water.

Flash Flood in LOGAN, COLORADO
From 09-MAY-15 04:45:00 to 09-MAY-15 06:30:00 (MST-7)
Location: PADRONI
Flood cause: Heavy Rain
Property damage: 25.00K
Crop damage: 10.00K
Reported by: Emergency Manager

Heavy rain coupled with already swollen rivers and streams produced flash flooding.  Numerous county roads were inundated by floodwaters.

Flood in LARIMER, COLORADO
From 09-MAY-15 15:00:00 to 09-MAY-15 19:50:00 (MST-7)
Location: TIMNATH
Flood cause: Heavy Rain
Property damage: 100.00K
Crop damage: 10.00K
Reported by: Emergency Manager

High water levels prompted the release of water through the Fossil Creek Dam Spillway near Interstate 25, southwest of Ft Collins.  Some road closures included:  CR 23, from CR 50E to CR 52E; CR 43, from CR 51B to just east of Glen Haven; CR 15/CR 6C intersection, from CR15 to CR15A to Berthoud.

Flood in WELD, COLORADO
From 09-MAY-15 15:00:00 to 09-MAY-15 19:50:00 (MST-7)
Location: SEVERANCE
Flood cause: Heavy Rain
Property damage: 15.00K
Crop damage: 5.00K
Reported by: Emergency Manager

Heavy rain produced flooding along already swollen creeks and streams in southwestern Weld County.

Flash Flood in ARAPAHOE, COLORADO
From 09-MAY-15 08:00:00 to 09-MAY-15 09:30:00 (MST-7)
Location: PEORIA
Flood cause: Heavy Rain
Property damage: 15.00K
Crop damage: 5.00K
Reported by: Broadcast Media

Floodwaters damaged Arapahoe County Road 42 at the Kingsburrow Bridge.  Water overtopped the road at several locations.

Flood in JEFFERSON, COLORADO
From 09-MAY-15 08:28:00 to 09-MAY-15 19:30:00 (MST-7)
Location: INDIAN HILLS
Flood cause: Heavy Rain
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Heavy rain and rising levels of South Turkey Creek washed out many driveways.

Flood in LOGAN, COLORADO
From 09-MAY-15 10:30:00 to 14-MAY-15 09:00:00 (MST-7)
Location: PEETZ
Flood cause: Heavy Rain
Property damage: 200.00K
Crop damage: 50.00K
Reported by: Emergency Manager

Numerous roads were impassable across western Logan County due to excessive runoff from Pawnee Creek and the South Platte River.  Road closures included:  CR 113 from the Nebraska line to CO 138; CR 72 from CO 113 to CR 51; CR 51 from CR 72 and CR 74; CR 39 from CR 66 to CR 68; CR 49 from CR 72 to CR 74; CR 20 from CR 9 and CR 11; CR 21 and CR 21.5 at CO 14; and CR 37, one half mile north of CR 52.

Flood in MORGAN, COLORADO
From 09-MAY-15 12:00:00 to 14-MAY-15 08:00:00 (MST-7)
Location: GOODRICH
Flood cause: Heavy Rain
Property damage: 500.00K
Crop damage: 100.00K
Reported by: Emergency Manager

The combination of saturating rains in the first part of May, and the May 8th and 9th heavy rain storms, produced more water than the creeks and drainages could handle. Flooding due to rain water started to move east through the county washing over county roads, both dirt and pavement).The southwest and northeast portions of the county were greatly affected and the majority of roads in these areas we impassable by vehicle due to water either running over the roads or water cutting trenches through the road.  County roads throughout Morgan County were inundated by floodwaters.  Some parts of the county received at least 10 inches of rainfall over a two week period.

Flood in LINCOLN, COLORADO
From 09-MAY-15 18:00:00 to 10-MAY-15 12:30:00 (MST-7)
Location: GENOA
Flood cause: Heavy Rain
Property damage: 15.00K
Crop damage: 10.00K
Reported by: Law Enforcement

Heavy rain produced widespread flooding.  Several county roads were impassable.

Flood in WELD, COLORADO
From 08-MAY-15 22:00:00 to 15-MAY-15 12:30:00 (MST-7)
Location: ERIE
Flood cause: Heavy Rain
Property damage: 500.00K
Crop damage: 100.00K
Reported by: Trained Spotter

Flooding resulted in numerous road closures in the vicinities of Barnesville, Briggsdale, Firestone, Frederick, Ft Lupton, Gill, Highland Lake, Keenesburg, Kersey, Mead, New Raymer, Riverside Reservoir near Masters, Roggen, Riverside Reservoir near Masters, and Windsor.

Flash Flood in MORGAN, COLORADO
From 09-MAY-15 02:40:00 to 09-MAY-15 04:30:00 (MST-7)
Location: BRUSH
Flood cause: Heavy Rain
Property damage: 25.00K
Crop damage: 10.00K
Reported by: Emergency Manager

Several roads in the Brush area were inundated by floodwaters.

Flash Flood in MORGAN, COLORADO
From 09-MAY-15 08:00:00 to 09-MAY-15 09:45:00 (MST-7)
Location: HOYT
Flood cause: Heavy Rain
Property damage: 25.00K
Crop damage: 10.00K
Reported by: Emergency Manager

Numerous roads in southwest Morgan County were inundated by floodwaters.

Flash Flood in MORGAN, COLORADO
From 09-MAY-15 08:20:00 to 09-MAY-15 09:30:00 (MST-7)
Location: BRUSH
Flood cause: Heavy Rain
Property damage: 25.00K
Crop damage: 10.00K
Reported by: Emergency Manager

Heavy rain continued to produce flooding and flash flooding, inundating numerous roads across east central Morgan County.

Flash Flood in ELBERT, COLORADO
From 08-MAY-15 23:03:00 to 09-MAY-15 01:00:00 (MST-7)
Location: KIOWA
Flood cause: Heavy Rain
Property damage: 25.00K
Crop damage: 10.00K
Reported by: Law Enforcement

Flooding and flash flooding washed out several county roads including:  CR73 from CR112 to CR98;  Freese Road from Colorado 86 to CR112; CR102, from Double Tree Ranch to the top of the Bluff; CR9 between Colorado 86 and CR98; CR106, from Canyon Road to CR13; Maul Road also suffered extensive damage.

Flood in BOULDER, COLORADO
From 08-MAY-15 20:14:00 to 09-MAY-15 08:00:00 (MST-7)
Location: LYONS
Flood cause: Heavy Rain
Property damage: 100.00K
Crop damage: 10.00K
Reported by: Emergency Manager

Heavy rain caused flooding of businesses along the Saint Vrain River in Lyons, south of Bohn Park.  Several basements in Boulder County were reportedly flooded.  Some flooding was also reported along Coal Creek, upstream of Erie.  Road closures included the westbound lane of Arapahoe Road, between County Line Road and 119th Street.