Flash Flooding and Hail in Arizona, August 18, 2021

Dirt road up to Reevis Mountain School, which cuts through Campaign Creek, was washed out by significant flash flooding. A couple yurpees on the property of the school were damaged or destroyed. Their fire circle and labyrinth were also washed away. The school and road are inside the 2019 Woodbury burn area. Rainfall of 4.5 inches was measured in 3 to 4 hours. Timing based on radar. No injuries were reported.

Multiple photos and videos show significant flow within the typically dry Reno Creek with flow over Old Highway 188, leading to its closure. Runoff may have been enhanced by the 2020 Bush Fire burn area. Reno Creek would experience another flash flood again in the early afternoon following another round of heavy rain upstream. This kept 188 closed for an extended period. No damages or injuries were reported.

Multiple photos and videos showed a few feet of rapidly flowing water within Campaign Creek, leading to the closure of Mesquite Street in Roosevelt Estates. One video even showed a 6 to 8 foot standing wave of water. Video after the water receded showed significant damage to the road. No injuries were reported.

Video shows considerable flow through Pinal Creek with at least 6 inches of swift-moving water over Beer Tree Crossing near Jess Hayes Road. Rainfall of 1.5 to 2 inches was measured in the area and upstream. Runoff may have been enhanced by the 2021 Telegraph burn area. No damages or injuries were reported.

Photos and videos show large sections of Russell Road, in multiple spots, were eroded and washed into Russell Gulch during significant flash flooding. Some photos, after the water receded, suggest the floodwaters may have been 6 to 8 feet deep. The significant destruction of Russell Road occurred roughly 2 miles south of the catastrophic flooding that occurred in the Claypool area, between Miami and Globe. Timing based on webcam footage in the area. No injuries were reported.

After 2 to 4 inches of rain fell, beginning around 0830MST, over the 2021 Telegraph burn area, catastrophic flooding occurred in Claypool area between Miami and Globe. Runoff mostly collected in Russell Gulch and a few feet of floodwaters moved downhill through the Claypool community. Security cam footage from a pizza shop showed floodwaters reached US-60 near mile post 247 around 1056MST. US-60 became impassible a couple minutes later and was closed in both directions for a couple hours before being reopened around 1240MST. The same areas were impacted again in the mid-afternoon after another wave of flash flooding move through the area. The Gila County Emergency Manager estimated over 50 homes and structures were damaged by flooding. Included in the damage was the pizza shop with the security footage, which was fully surrounded by flooding. A hotel next to the pizza shop had all of its ground level rooms flooded, including a wall that collapsed due to the force of the water. Roads to the nearby hospital were cutoff by floodwaters. The hardest hit area was Little Acres Mobile Home Park, 1 mile south of US-60. Most if not all of the mobile homes had flood damage as an estimated 4 feet of water and mud moved through the park. Security footage shows one home was even swept from one side of the park to the other and was destroyed. Many of the owners were displaced from their homes for several days while the park was cleaned. A power substation next to the park also experienced significant flooding. Fortunately there were no injuries or fatalities reported from this event.

Multiple photos and videos show significant flow in Pinto and Spring (tributary to Pinto) along State Route 188 near mile post 234. One photo showed a storage structure (possibly abandoned) in Spring Creek with roughly 8 feet of water flowing through it. It is unknown if the structure had any damage. Many of the photos and videos were posted in the early afternoon, but flood impacts likely began in the morning after 2 to 4 inches of rain fell over the 2019 Woodbury burn area. No injuries were reported.

Arizona Department of Transportation reported State Route 77 was overtopped by floodwaters at mile post 163.2. Timing based on report time and radar. No damages or injuries were reported.

Arizona Department of Transportation reported State Route 188 was closed in both directions near mile post 219 due to flooding. No damages or injuries were reported.

A USGS streamflow gage along Pinal Creek near Inspiration Dam measured multiple a couple rapid rises between 1230MST and 1430MST with a peak stage cresting at 8 feet. The flood waves likely originated from heavy rain roughly 15 miles upstream over the 2021 Telegraph burn area southwest of Globe. There were a couple more smaller follow-on waves that were recorded as the flow was decreasing from its crest. No damages or injuries were reported.

Heavy rainfall led to a rapid increase in flow in Sycamore Creek. A Maricopa County Flood Control District stream gage along Sycamore Creek near NF-201 and Beeline Highway recorded the creek climbing above alarm stage, cresting at 4.54 feet at 1247MST. Downstream impacts included old SR 87 and low-lying homes. No damage or injuries were reported.

Photos and videos show considerable floodwaters, roughly a few feet deep, rapidly moving down Reno Creek and flowing across Old Highway 188, making it impassable. Runoff may have been enhanced by the 2020 Bush Fire burn area. Reno Creek flooded earlier in the morning as well. No damages or injuries were reported.

A camera located along Kitty Joe Creek showed high, swiftly moving flow that was nearly topping the banks of the creek. No damage or injuries were reported.

Multiple large trees uprooted in the area of 19th Ave between Missouri Ave and Maryland with some trees falling into and blocking streets. One tree was 30 feet tall and had a 12-18 inch diameter trunk. A large tree also reportedly fell at Palo Verde golf course. Timing was based on radar and wind gusts were estimated up to 50-60 mph with downburst signatures evident on radar. No injuries were reported.

FCDMC STREAM GAUGE

A Maricopa County Flood Control District stream gage located along Indian Bend Wash at Shea Boulevard exceeded alarm stage, resulting in impacts to downstream low water crossings as well as to the Indian Bend Wash greenbelt. At 1501MST, flow in Indian Bend Wash crested at 3.02 feet and 2031 CFS. According to a nearby mPING report close to Paradise Valley Mall, a flooded street led to a vehicle becoming stranded. No injuries were reported.

A portion of the roof of an apartment complex near 7th Avenue and Hatcher Road was torn of in strong winds and landed on an unoccupied parked car, causing damage. Nearby, multiple photos on social media showed several downed saguaros with one of them causing some damage to the front of a home near 12th Street and Northern Avenue. Winds estimated around 60 to 65 mph. No injuries were reported.

Multiple reports of wind damage from a microburst along Peoria Avenue between 35th and 43rd Avenues. A couple large pine trees fell on an apartment complex, causing damage to the edge of the roof. A tree fell on 2 unoccupied parked cars at another apartment complex, causing major damage. A 1-foot diameter tree fell on an unoccupied parked car at a business plaza. There was also a partial roof torn off reported in the area. Winds were estimated around 60 to 65 mph. Timing based on radar. No injuries were reported.

The Cave Creek Ashdale Maricopa County Flood Control District stream gage recorded flow exceeding alarm stage, impacting low water crossings along with properties in the area. At 1513MST, the creek crested at 6.7 feet and 2027 CFS. No damage or injuries were reported.

A couple videos showed significant flowing water through Skunk Creek with flow over Honda Bow Road. One of the videos showed someone being rescued on the hood of a truck by a good Samaritan from their SUV that stalled in the floodwaters. Rainfall amounts over 1 inch were observed over the foothill areas upstream of this location. Timing of impacts adjusted based on radar. No injuries were reported.

According to local media reports, the Maricopa County Sheriff's Office found two people had perished inside an ATV that was buried in mud and debris downstream in Camp Creek. MCSO was notified and began searching for the missing people around 1600MST on the 18th but did not recover the ATV until 0800MST on the 19th. Media reported that other recreationists were successfully rescued from the area, including a father and daughter who were trapped near Needle Rock Recreation Site and had to be rescued by helicopter. A Camp Creek rain gauge recorded 3.54 inches of rain between 1300MST and 1420MST. The Rackensack Canyon rain gauge measured 3.83 inches of rain between 1250MST and 1430MST. The Maricopa County Flood Control District also reported that Bartlett Dam Road was closed due to swiftly flowing water over the roadway from Camp Creek.

Old Stage Road and parts of New River Road were closed due to flooding associated with increased flow in New River. A Maricopa County Flood Control District upstream from the impacts climbed above alarm stage, cresting at 2.93 feet and 2801 CFS at 1442MST. No damage or injuries were reported.

Videos show significant floodwaters in Galloway Wash with flow across Spur Cross Road, making the road impassable to all traffic. Measured and radar estimated rainfall amounts were around 2 to 4 inches in 2 to 3 hours over areas upstream of this location. Timing adjusted based on radar. No damages or injuries were reported.

Significant flow in a typically dry wash made Carefree Highway between Tom Darlington Drive and Stagecoach Pass impassable to all traffic. There was also a photo that showed a lot of mud and gravel in one of the southbound lanes of Tom Darlington Drive near Meander Way. Both of these were reported around 1550PM. Very heavy rain began over the area and just upstream closer to 1300MST, with measured and radar estimated rainfall amounts of 2 to 4 inches in 1 hour. Timing of impacts adjusted based on radar. No damages or injuries were reported.

A Maricopa County Flood Control District stream gage along Seven Springs Wash exceeded alarm stage, impacting the unbridged Seven Springs Road downstream. At 1418MST, the flow crested at 5.06 feet and 1574 CFS.

Broadcast media coverage showed significant flow in East Fork Cave Creek leading to the closure of 7th Avenue near Coral Gables Street. A Flood Control District of Maricopa County streamflow gage a few hundred feet upstream from 7th Avenue exceeded alarm stage at 1422MST, crested at 3.66 feet at 1509MST, and fell back below alarm stage at 1645MST. A man tested the floodwaters with his unicycle, but wisely turned around. No damages or injuries were reported.

A Maricopa County Flood Control District stream gage along Cave Creek north of Carefree Highway exceeded bank full stage, impacting downstream low water crossings. At 1502MST, the creek crested at 7.65 feet and 5178 CFS. No damage or injuries were reported.

Videos from a local TV station showed deep, swiftly moving water flowing in a wash across an unbridged crossing along 7th Avenue near Coral Gables Drive in Moon Valley. Nearby, Greenway Road was closed at I-17 due to flooding. No damage or injuries were reported.

A large tree, possibly a palm tree, was blown down onto power lines along Extension Road between 2nd Street and 2nd Place, causing a power outage to approximately 600 customers. Winds estimated around 55 to 65 mph. Timing based on radar. No injuries were reported.

Arizona Department of Transportation closed State Route 88 between mile posts 230 and 242 due to flooding. Timing of impacts based on radar. No damages or injuries were reported.

Arizona Department of Transportation closed State Route 188 in both directions due to a mudslide across the highway. Initially the closure was between mile posts 246 and 255, but was updated to between 252 and 255. The mudslide was around mile post 253 and was the same location as a debris flow in July 2020. Runoff may have been enhanced by the 2020 Bush Fire burn area. Photos of the mud slide show roughly 1 to 3 feet of sediment, with burnt tree branches and twigs, across the highway and the guardrail in the southbound lane was destroyed. No injuries or additional damages were reported.

After 2 to 4 inches of rain fell over the northern portions of the 2020 Bush Fire burn area, a USGS streamflow gage on Sycamore Creek (SYCA3) registered a rapid rise from 2.53 feet at 01530MST to 9.38 feet at 1545MST. Flow continued to rise and crested 11.77 feet at 1730MST, 1.73 feet below action stage. No damages or injuries were reported.

The unpaved portion of State Route 88/Apache Trail was closed between NF-79 (mile post 230) and NF-51 (mile post 242) due to significant flash flooding and the road being washed out in many places. Arizona Department of Transportation reported the closure on the 19th, but the flooding impacts occurred on the 18th. According to Apache Lake Marina & Resort, some customers and employees had to be evacuated out of the area. Videos on social media show some of the road damage and washouts. The nearest rain gage at Reavis Trailhead measured 1.61 inches between 1350MST and 1550MST and radar estimates were upwards of 2 inches. Runoff on the southern end of the closure may have been enhanced by the 2019 Woodbury Fire burn area. Timing based on the rain gage and radar. No injuries were reported.

A photo showed an outhouse public bathroom at the Eads Wash River Access Point Recreation site had the ground beneath it eroded away due to flash flooding. Floodwaters appeared to be traveling within Poison Spring Wash toward the Salt River. Tonto National Forest posted a couple days later that access to the Eads Wash rec site was closed due to erosion damage and unsafe conditions in the area as a result of the flash flooding. Exact timing of when impacts occurred is unknown, so based the timing off of radar. No injuries were reported.

A Maricopa County Flood Control District stream gage along Cave Creek at Cactus Road recorded flow climbing above alarm stage, impacting nearby low-lying areas. At 1632MST, the gage crested at 11.14 feet and 1,567 CFS. No damage or injuries were reported.

Video shows significant flow in Six Shooter Canyon with floodwaters overtopping a small bridge at Six Shooter Canyon Road and Delores Lane. Homes may have been impacted with this flow level, considering a previous event, but there were no reports of damages and no reports of injuries either. It is uncertain if this event occurred in the morning or afternoon, but a downstream gage at Beer Tree Crossing registered a greater rise in the afternoon versus the morning. The gage crested at 3.91 feet at 1659MST. Although not reported, Beer Tree Crossing was likely impassable.

Gila County Emergency Manager reported Russell Gulch experienced flash flooding, in the Claypool area between Miami and Globe, after heavy rain fell over the Pinal Mountains within the 2021 Telegraph Fire burn area. Measured and radar estimated rainfall amounts were around 1 to 2 inches over the area and upstream, bringing the day's total to around 2.5 to 4.5 inches over the burn scar. Flash flooding impacted the same areas as the catastrophic flooding earlier in the morning, but was less intense according to the emergency manager. Still the bridge to the hospital near Hospital Road and Russell Road was impassable and nearby homes likely experienced impacts again. No injuries were reported and there were no reports of new damage costs.

Pictures on social media show multiple snapped tree due to strong downburst winds. Wind speeds estimated around 55 to 60 mph. Timing based on radar. No injuries were reported.

Roads into Bartlett Lake were reported to be flooded and impassable in multiple locations, with some people having to be rescued out of the lake area.

Numerous trees down across Ahwatukee with many along Desert Foothills Parkway and Chandler Boulevard over to Ray Road. Many of the trees were palo verdes and several fell into roads and impeded traffic. Winds estimated around 50 to 60 mph. Time based on radar. No injuries were reported.

Arizona Department of Transportation reported State Route 238 was closed for several hours between mile posts 35 and 40 due to flooding. Timing of impacts based on radar. No damages or injuries were reported.