Preparing for El Niño on the LA River
Following a dry summer, on Sept. 15, a parched Southern California received rain, with more than 2.39 inches falling in Los Angeles in just a few short hours. The rain had left the L.A. River swollen with water, transforming it from its usual trickle to a raging torrent. Swift Water Rescue Teams were called to retrieve fourpeople and a dog that were swept away in the harsh current towards the sea. The river's typically dry bed attracts a number of recreational users who bike, jog and fish and others who seek shelter on the islands of vegetation and underneath rafters who, when caught unaware, can easily get caught in the torrent that can reach up to 45 mph. Considering how tame the river is most of the year, people can forget that the river was altered to act as a flood channel designed to whisk water out to the ocean quickly and efficiently, causing waters to rise quickly and move rapidly.
The recent storm was just a fraction of what is to be expected if the predictions for a "Godzilla" El Niño this winter are realized. Forecasts suggest that this El Niño could be the strongest ever, surpassing the strength and destruction of the El Niño of 1997, which brought on deadly flooding and mudslides and gave Southern California double its annual rainfall. The river was channelized to keep the regularly flooding river under control, but with mother nature's unpredictability, nothing is unexpected and agencies that monitor the safety of the river's infrastructure and nearby human life are taking extra precautions to keep the river safe this rainy season by increasing swift water rescue training and making repairs to the river's levees and dams.
"This is usually the time of year where the swift water rescue team begins to prepare for the rainy season, certainly this year in anticipation of El Niño we are ramping up our training," said Gonzalo Medina, Marine Safety Chief of Long Beach Fire Department. "We train like our lives depend on it because they do."
Those onLong Beach Fire Department's Swift Water Rescue Team take more than 100 additional hours of specialized training, which includes swift water rescue, inflatable boat operations and flood rescue technique. In anticipation of the heavy rain season, they are currently identifying potential high flood-risk areas in dense urban neighborhoods and pre-deploying inflatable rescue boats to areas that are known to have a tendency to flood.
The specialized training came in handy during a rescue to extract 3 people from the river in September. They used a vertical haul rope system — sending down a rope with a harness for those in the river to connect to, and then hauled them out vertically onto safe ground. "Using the rope system, we are minimizing the risk of putting somebody in the water and maximizing the return by providing for life safety and rescue," Medina said.
The Long Beach Swift Water Rescue Team has jurisdiction of the river south of Del Amo Boulevard in Carson. The 30-member team includes a combination of fire fighters, urban search and rescue and marine safety personnel, who have on-duty units in close proximity to flood channels. $60,000 of the Marine Safety Budget is allocated yearly to Swift Water Operations. The number fluctuates depending on the amount of rain anticipated and they are anticipating the number will increase next year due to El Niño, Medina said.
The homeless population that finds shelter in the rafters underneath the river's bridges and in soft-bottom sections of the river with large swaths of vegetation are most at risk of finding themselves in danger during a storm. Long Beach tries to take a holistic approach when evacuating the river prior to a storm, Medina said. It deploys active lifeguard patrols to the riverbed to advise recreational users of the river and those living in the river of the possible dangers. Patrols work closely with the Long Beach Police Department and the Long Beach Department of Health and Human Services to get people out of high danger areas and direct them to emergency shelters or to the Long Beach Multi-Service Center that can provide them with shelter, housing vouchers and health services.
A rescue can cost tens of thousands of dollars and could require swift water teams from Los Angeles Fire Department and Los Angeles County Fire Department as well as a number of rescue apparatuses — from helicopters to boats, sometimes both. "River rescues take a large amount of inter-agency participation because when somebody falls in the water, they don't know where they will go in and where they will come out," Medina said.
Although recreational areas near the river, like those at the Sepulveda Basin or Glendale Narrows, have an open season that runs from Memorial Day to Labor Day, the trails, bike paths and walking paths remain accessible during the rainy season. With plans moving forward to make the length of the L.A. River a recreational and living destination, Thomas Henzgen, Fire Captain with Los Angeles Fire Department, believes the plans will cause an increase in the number of rescues in the river.
"On the rescue side, we don't see the river as a recreational area. In our eyes, it's a flood control channel designed to move a lot of water in a short period of time through the L.A. area and out to the ocean, so that nothing floods. If you tell people they can play in the river certain times of the year and they can't play during other times of the year, they're only going to remember the times they can play. So when the river becomes dangerous, chances are they will still go down there," Henzgen said.
While Fire Departments along the river are working to keep people out of the river, the Army Corp of Engineers and the Los Angeles County Flood Control District are doing everything in their power to keep the water from escaping the river channel.
Following a massive flood in 1938, which left homes and businesses near the river destroyed and more than 100 people dead. There are now nine levees in the river, spread out from the Sepulveda Dam down to the ocean in Long Beach. The five levees upstream of the Rio Hondo Confluence and Compton Creek are maintained by the Army Corps and the four levees downstream of that are maintained by Flood Control District. There are portions where there are no levees, though an improved concrete-lined channel conveys the flow down the river.
The Flood Control District does maintenance along the river on a regular basis, which includes the reinforcement of concrete panels and replacing pieces of old or damaged infrastructure. Maintenance personnel regularly check the levee system and "hot spot" areas that have high mud and debris flow and tend to have high instances of flooding, said Kerjon Lee, a spokesperson for the flood control district. In neighborhoods they see as high-risk, they've built rail and timber structures to shore up the hillside.
"Maintenance repair is ongoing and we are regularly monitoring the area to make sure everything is in good working order," Lee said.
The storm in September brought the river's levee system and dams to full capacity, said Richard Leifield, chief of engineering at the Army Corps. "Upstream of the river, prior to the Rio Hondo Confluence, the river would not be able to convey the 100 year storm. However, downstream of the Rio Hondo Confluence, improvements were made in 1990 and the river can now convey more than the 100 year storm," said Leifield.
Considering this coming El Niño could bring rains stronger than the 100 year storm, the Army Corps and the Flood Control District plan to remain in close coordination during the rainy season, said Leifield. During a flood event, the Flood Control District has a team that patrols the river, watching out for trouble areas along the levee system and the Army Corps has a team of "channel observers" who, through visual inspections, make sure there is no erosion taking place on the banks or any other type of damage that could prevent the water from being safely conveyed. The Army Corps has a team ready to respond if there is any trouble by warning those nearby and by getting an emergency contractor to do quick reinforcements.
"Dependent upon mother nature and how significant the rain and the runoff is, whatever flood system we build there's a chance that it could be succeeded. And that's definitely the case with the L.A. River," Leifield said.
The Army Corps does an annual routine inspection to the levees and its facilities. A more thorough periodic inspection happens every 5 years, conducted by a team of engineers that walk the entire levee system for a complete analysis. The purpose of the inspection is to "identify deficiencies that pose hazards to human life or property" and is intended to identify areas that need further studies or immediate repairs. The last periodic inspection took place in 2013 and rated fice of the eight levees as "Unacceptable" out of a rating system that ranges from "Minimally Acceptable," "Acceptable" to "Not Applicable." The problems identified included significant amounts of vegetation and debris impeding the flow of drainage systems and erosion. Problems which the Corp is actively working to repair, said Jay Field, spokesperson for the Army Corp of Engineers.
"The county has done a great job repairing nearly everything that has been identified as needing repairs in the periodic inspections and most of the repairs have been done. The Corps suffers from a lack of funding, so we haven't been able to make as many repairs as the county has made, but it is definitely on our list of work we need to accomplish," said Field. The Corp received more than $750,000 in funding in 2016 for channel maintenance and is currently seeking funding to complete the repairs needed between now and the end of December.
"All the agencies are very aware of the El Niño predictions. Every winter we get ready, but this winter we're doing extra efforts to get ready and doing everything we can to be as ready as we can because of the prediction of a wet winter," Leifield said.