Antelope Valley Report Blames Poor Drainage Practices for Flooding

Storm flooding that damaged dozens of homes in the Quartz Hill area of the Antelope Valley was caused more by poor drainage measures there than by the collapse of flood basins in nearby Palmdale, according to a Palmdale-sponsored report released Friday.

The report said homes in the unincorporated Quartz Hill area would have been flooded by the heavy storms in February and March even without the failure of at least three detention basins in Palmdale.

But without blaming the city, the report also urged Palmdale to require developers to build much stronger basins.

Quartz Hill resident Dale Valdivia, leader of a flood victims group, rejected the report’s chief conclusion, continuing to insist along with county officials that recent development in Palmdale was responsible.

“How come nobody ever got flooded before?” Valdivia asked.

Palmdale and Quartz Hill residents in recent months have filed about 75 claims against Palmdale seeking about $1.5 million in flood damages.

Palmdale thus far has settled 25 of those, mostly smaller ones, for payments totaling $68,268.

But many of the larger claims remain unresolved.

Some residents had been hoping that the report by the city’s consultant might provide them with ammunition for pressing their claims or a potential lawsuit.

But the report skirted placing any blame on Palmdale, arguing instead that poor drainage and development practices in county areas were at fault.

The Palmdale City Council authorized the investigation shortly after the flooding, hiring the Colorado-based engineering firm of Daniel, Mann, Johnson & Mendenhall for $49,600.

City officials Friday pledged to act on the report’s recommendations for stronger flood-control basins.

The consultant said many residences in Quartz Hill, which is under county control, were damaged by floodwaters primarily because they were built on streets without curbs and gutters, with floor levels lower than street levels, and without adequate drainage.

The initial failure March 1 of a detention basin at Kaufman and Broad’s California Chateau development in Palmdale, and the ensuing floodwaters that swamped two other nearby basins built by Pacifica Development, “only added somewhat” to flooding downhill in Quartz Hill, the report said.

“Drainage problems very likely existed in the Quartz Hill area long before any development took place in what is now northwest Palmdale. They will continue to exist until a system to collect and convey storm water out of the area is constructed,” the report said.

Aides to county Supervisor Mike Antonovich, who represents the Antelope Valley, said they could not comment on the consultant’s findings because they had not seen the report.

But in the past, Antonovich has contended that it is development in Palmdale that lacks adequate flood control.

Nevertheless, in the wake of the flooding, the city and county have agreed to explore resurrecting long-delayed plans for an Antelope Valley flood-control district.

In the past, local residents balked at such proposals because they would be assessed to pay for the projects.

Among its findings, the report said the failures of the earth detention basins in Palmdale occurred because rising floodwaters in them eroded areas of the embankments near their outlet pipes, allowing the pent-up water to spill out.

The consultant recommended a long list of basin improvements, including using concrete reinforcements.

The report’s author said the improvements should have been required by the city.

Asked why the city had not done so, City Engineer John Mundweil said: “I don’t know. I can’t tell you.”