Report tracks water during July flooding events on Abrego

Gauges in nearby watersheds recorded nearly two inches of rain on July 22, and 2.7 to 5.5 inches on July 24, as two significant storms rolled through the area.

A post-storm analysis by Flood Control hydrologists revealed that water broke out of the channel, known as Green Valley Drainageway 1, at two locations: one upstream, between Interstate 19 and 79 E. Duval Road (the first home east of I-19), and another downstream, at the four cell box culvert under Abrego Drive.

Further post-flood observations noted the culverts under Abrego Drive were completely obstructed, forcing water out of the channel to the north and the south, and eventually down a utility easement that flowed into the Casas de Abrego neighborhood.

Impact and clean-up

According to the report, houses off of Via Terrenal in Green Valley’s Casas de Abrego neighborhood were the hardest hit during the flood event, where homeowners saw four to eight inches of water inside their living rooms and garages.

Floodwaters also deposited a large volume of sediment – up to a couple feet in some areas – that buried gas meters and muddied roads in the 43-home subdivision for days.

In the Town of Sahuarita, two homes on North Avenida Mena, just north of Duval Road, experienced flooding in their garages, but no significant water damage was reported in any habitable parts of the home, the report stated.

In the days and weeks following the July storm, Pima County Regional Flood Control District assisted homeowners and the Town of Sahuarita with the clean-up efforts, providing roll-off dumpsters to dispose of water-damaged property and clearing sediment and vegetation from the culvert and the downstream channel to improve drainage.

On Aug. 19, after nearly a month of work, all four cells under Abrego Drive had been cleared.

Who’s responsible?

Pima County Department of Transportation confirmed that maintenance of the culverts and the drainage underneath Abrego Drive is the responsibility of the Town of Sahuarita.

While the report confirmed the drainageway upstream of the box culverts under Abrego Drive is the responsibility of the HOA for La Joya Verde Rancho Abrego III, the boundaries of a public drainage easement indicate mixed responsibility for the drainageway east of Abrego Drive.

To alleviate confusion, Pima County Regional Flood Control District has recommended to the HOA and the Town of Sahuarita that the town assume maintenance of the entire channel downstream of Abrego Drive.

Pre-flood conditions

According to the report, little is known about the conditions of the drainageway prior to July’s storm event.

As part of a larger 2014 study of Green Valley drainageways, Pima County Flood Control identified “significant sedimentation within the drainageway” under Abrego Drive, noting that the culvert was about 80 percent blocked by sediment during the time.

In a letter sent to the Town’s engineer in April 2014, Flood Control notified officials of drainageway issues highlighted by the study, and recommended the Town “perform necessary maintenance” to resolve them.

While the Town stated they did conduct maintenance as a result of the letter, Flood Control “does not currently have any details about that maintenance,” according to the report.

A Town spokesman said they don’t have “any real way of confirming receipt of that letter or any official town response to it.”

It was also noted that Director of Public Works Beth Abramovitz was not on staff at that time and neither were most of the maintenance staff now employed with the town. Abramovitz started at the town in 2017, and became director in 2019.

The report does state that the drainageway appeared “more open in 2016 than in 2020,” when an aerial photograph taken May 21, 2020, appears to show the box culverts under Abrego Drive partially obstructed with sediment.

Pre-storm conditions of the drainageway upstream and downstream of the culverts are even less clear, the report stated, as aerial photographs were not useful in determining sediment levels of the channel.

No records

The Town of Sahuarita confirmed to the Sahuarita Sun/Green Valley News that they are responsible for maintaining the culvert. However, it said it has no records, maintenance logs or documents to prove when maintenance last occurred on the culvert. The town also did not know how long the culvert had been its responsibility.

Abramovitz said that in the past the town didn’t have a specific policy on what types of maintenance logs town personnel needed to track.

“Some of them may have written things down in a log book but there are others who probably never documented their work,” she said via email.

Culverts and other storm water features were also not included in the town’s asset management system in the past, something Abramovitz said they are adding in now so they “can keep records of the work moving forward.”

She said they had a temporary employee through the end of the last fiscal year working on entering storm assets, like culverts, into an asset management system.

While there are no records indicating the last time the culvert under Abrego was maintained, Abramovitz said they have a checklist of tasks they perform prior to any storm.

Abramovitz said the culvert at Abrego was challenging when it came to whose jurisdiction it was.

She said very few of the washes in town are actually the responsibility of the town to maintain. Some of the washes are the responsibility of HOAS, some are the responsibility of Pima County and others are maintained by developers.

She noted that town staff noticed several types of residential debris in the wash as they were helping to clean the area after the storm and flooding.

“It was noted that there was a significant amount of debris, such as landscape waste (branches with clean cuts), two shopping carts, and other items, which get lodged in the culverts and trap sediment,” she said. “In extreme weather events like this one a certain amount of debris will wind up in washes and culverts, but there is also some responsibility on the part of homeowners who look at washes as convenient ways to dispose of landscaping and other debris.”

John Stichter, head of the Casas de Abrego HOA, said the neighborhood still has not recovered from the one-two punch of July storms.

He said they appreciate the county providing dumpsters, which have been filled several times with carpet, ruined furniture and other items damaged by water and mud. They were expected to be hauled off this week.

“It’s going to take some time to figure this out and do it in a fair way,” Stichter said.

A spokesman for Supervisor Steve Christy’s office said they are continuing to help the HOA work through issues and that a dozen homes in Casas de Abrego were affected.