Скачать с ютуб How better water systems can help a city in Colorado survive the next firestorm в хорошем качестве

How better water systems can help a city in Colorado survive the next firestorm

As a firestorm whipped through Boulder County on December 30, 2021, burning homes and businesses, technicians for the City of Louisville Department of Public Works and Utilities suddenly became front line workers. Hydrants trickled. Pumps and treatment plants lost power. Chemical contaminants were sucked into pipes. And water utility technicians worked swiftly to manage all of it. “When you respond to the fire, you're asking people to put their lives at risk that aren't even first responders. They're people that operate water systems,” said Kurt Kowar, Director of Public Works and Utilities for the City of Louisville, on Colorado’s Front Range. But Louisville wasn’t alone. There was Santa Rosa, Paradise, Lahaina and most recently, Los Angeles. All are places that have shown that American cities and their water systems weren't built to withstand wildfire, experts say. As wildfires grow more frequent and intense with climate change, and become a greater threat to cities, water utilities are reckoning with the reality that they must build back better. Better water infrastructure by itself won't protect neighborhoods from fire, experts say, and many of the ideas are expensive. But there are things that communities can do. Here are some of them: Remote shutoff valves As buildings burn, so do their pipes, which spill water until a utility worker can safely get in to shut off the supply valve. The delay can be hours or days, all while precious water for firefighting is lost. Since the Marshall Fire burned more than 500 homes in the city of Louisville, Colorado in 2021, the city has worked to install remote shutoff valves at meters at all the homes that have been rebuilt. A standard meter costs around $400, while one with remote shutoff capabilities is about twice that. They require cell signal to operate, making them a possible vulnerability if telecommunications are lost where fire is burning, but Kowar says swift action can reduce that risk. Remote shutoff valves can be installed on main distribution pipes, too, allowing utilities to redirect water more easily to areas that need it. Emergency water sources There's a simple idea for making water available to firefighting helicopters right in cities so they don't have to fly to distant reservoirs or the ocean. They're called “heli-hydrants” — concrete tanks that hold a few thousand gallons of water. Helicopters can fill up in less than a minute, and the heli-hydrant refills quickly from a gravity-fed tank. In November, a 5,000-gallon heli-hydrant in San Diego County was tapped nearly 30 times by aircraft fighting the 48-acre Garden Fire. The Rainbow Municipal Water District, a small utility that serves several unincorporated communities, paid around $200,000 to install its heli-hydrant in 2021 after the 2017 Lilac Fire burned more than 100 buildings nearby. Meanwhile, homes and businesses can take steps to protect themselves by storing water on site for firefighting. Some commercial properties and large residential properties, such as condos or apartment buildings, are already doing this. Those tanks can range from $100,000 to millions of dollars depending on size. Individual homes and neighborhoods can do the same, but only if they have deep pockets. A tank to protect a 2,000-square-foot home could cost $15,000 to $30,000, even before piping and a sprinkler system, according to engineers at CST Industries, which manufacture tanks. Dedicated pipes for firefighting It's not a fantasy: Separate, high-pressure pipes that move water— even ocean water if needed — across town to dedicated hydrants that can be tapped for the worst fires have been standard in much of San Francisco for more than a century after the 1906 earthquake sparked widespread fires that burned more than 500 city blocks. Today, 135 miles of pipe are fed by a reservoir and two large tanks, used only for the biggest fires. The city has a backup reservoir, 70 backup underground cisterns that hold 70,000 gallons each, and can pump in seawater if needed. The regular drinking water system is tapped first for small fires and is sufficient under normal conditions. Officials at the San Francisco Public Utility Commission, which owns and manages the system, say something similar would have helped in the Palisades Fire. The utility has invested billions to update the system and is expanding it to west and southeast neighborhoods over the next 15 years for another $4.5 billion. Building a comparable system today would be too costly for most communities, but elements such as additional cisterns, or a couple of high-pressure lines with dedicated hydrants in high-risk areas could be feasible, experts say.