Ahead of this month’s rain-related flooding, San Diego city officials repeatedly debated how fast and aggressively to perform the costly stormwater maintenance on its channels that are considered most prone to spilling over.
Officials said they inspected and cleared all of the city’s more than 24,000 storm drains and repaired several corrugated metal pipes in the run-up to the first series of storms.
Still, Alvarado Creek, the San Diego River and the Tijuana River overflowed in sections, leaving cars floating in large pools of rainwater. More than 500 reports of clogged drains, mudslides and flooded streets poured in from all over the city. In at least one case, an old storm pipe burst and flooded more than half a dozen homes.
Some lawmakers, led by Councilman David Alvarez, had prodded city departments starting in September to take significant action.
“I continue to be concerned about the city’s preparation efforts,” Alvarez said. “The flooding and incidents that occurred [earlier this month] are very telling that our city is not prepared for the next storm.”
The city acted aggressively to prepare in the run-up to the storms, said Bill Harris, spokesman for the city’s Public Works Department. “We did hurry up, and it literally made a difference.”
In November, the city began applying for emergency permits to clear flood channels. The paperwork was filed with the U.S. Army Corp of Engineers and the San Diego Regional Water Quality Control Board.
Maintenance was needed on as many as 25 sections of flood-control channels, according to a report released last fall. So far, the city has completed work on about nine of those areas, with three more in progress and at least six in line for the emergency permits approval. Clearing each section can cost anywhere from about $500,000 to $1 million.
Major structural damage caused by flooded channels has so far been identified only along Alvarado Creek, which the city cleared ahead of the series of storms, Harris said. Los Peñasquitos Lagoon in Sorrento Valley also overflowed and caused some damage.
“In all the areas where we performed maintenance, the channels performed as they were supposed to,” Harris said. “In some instances, like Alvarado creek, those channels were overwhelmed by the volume of rain.”
As development has paved over floodplains and wetlands, stormwater systems have become increasingly burdened. During heavy showers, dangerously fast-moving water rolls off roofs, parking lots and sidewalks, overwhelming storm drains and flood channels.
In regions such as Southern California that receive heavy but infrequent storms, spending tax dollars on getting rainwater out to the ocean and away from homes and businesses can raise tricky questions.
“What cities balance is the amount of rainfall they expect against cost,” said Sarah Elkind, a professor of environmental history at San Diego State University who specializes in urban policy and infrastructure.
“Every drainage system is built with a particular capacity, and that capacity is very rarely overbuilt,” she added. “Some of our drainage problems are designed into the system.”
For years, San Diego has had a multimillion-dollar backlog of stormwater needs. In general, it also has a billion-dollar-plus infrastructure spending gap.
If the city wanted to come up to speed on all needs associated with flood-risk management, it would have to spend about $250 million during the next five years as opposed to the $50 million it has allocated.
“If we put all the eggs in the stormwater basket, what are willing to sacrifice to do that? Do you want the Chargers or do you want to resurface half the roads that need regrading?” Elkind said.
In the meantime, homeowners can apply for insurance through the National Flood Insurance Program. An average policy in California costs about $850 a year. Nearly 40 percent of claims in the state are paid out during El Niño years. A new policy will take 30 days to go into effect.
In cases where the city is believed to be at fault, San Diego residents can also seek reimbursement for property damage through claims filed with its Risk Management Department.
To address flood and water-quality concerns, environmentalists have long called for limits on sprawling development, as well as boosting wetlands and open space to allow more stormwater to seep into the ground. When rain runs over city streets, it not only can cause property damage but also pick up bacteria, chemicals and other pollution that contaminate rivers, bays and beaches.
“It floods because we’ve built up impervious surfaces and disrupted the natural flow of water,” said Matt O’Malley, policy director for San Diego Coastkeeper. “We’ve accelerated its journey into streams, which we’ve then channelized with concrete, further disrupting the natural flow and pollution abatement and ecosystem services provided by natural systems.”
The region’s crisis-oriented approach to flood management leads to ecological destruction of natural waterways because vegetation that slows down and cleans stormwater is ripped out to protect property along flood channels, said critics of the practice.
“We need to get away from this gray, hardened infrastructure and implement green infrastructure projects that restore or mimic natural functions, recognize water as an asset and beneficial resource, and provide the pollution abatement and ecosystem functions we’ve lost,” O’Malley said.
The regional water quality board has issued new rules on stormwater that greatly increase the amount of water that new developments must capture on-site. To comply, contractors can use permeable pavement, build detention basins and install underground tanks that help feed rain slowly back into the ground.
However, cities like San Diego are already largely built out. To fully address the issue, these municipalities would have to spend billions of tax dollars over coming decades.
“We built in the middle of a flood plain,” said Livia Borak, legal adviser for the Coastal Environmental Rights Foundation. “It’s not like we didn’t know that that’s where the San Diego River overflows. We built around it knowingly thinking that we had done as much as we could that was cost-effective.”
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