Water is the city enemies of planners. Because the built environment is impervious to liquids, thanks to all that asphalt, concrete, and brick, water accumulates instead of seeping into the ground. That’s how you get severe flooding has been hard on California for weeks, so far 19 people killed and cause maybe 30 billion USD in damage.
Engineers traditionally view stormwater as a nuisance, building complex infrastructure like sewers and canals to channel floodwater into rivers or oceans before it has a chance to form a puddle. But in California and elsewhere, climate change is forcing a shift in that strategy. As the world warms, more water evaporates from the land into the atmosphere, which itself can hold more water as it gets hotter. Storms in the Golden State will come less often, but pour more water when they do. Rainwater drainage systems cannot drain water fast enough.
To prepare for this soggy future, engineers are turning to a different plan for flood control, forcing water to seep underground into natural aquifers. Such a plan would simultaneously reduce flooding and help the American West store more water despite a worsening climate. “We need to think a little more creatively about: How do we make the most of essentially these giant underground sponges that we can use to provide drinking water? ” Katherine Kao Cushing, who studies sustainable water management at San José State University, said.
California’s water system is built for the Mediterranean climate. Rainfalls in the fall and winter fill the reservoir system, providing water for the entire state during the dry summer. But that system is strained during a drought, like the one that is ravaging the state: The past three years have been a period of time. driest three-year period since 1896. (Drought maybe actually aggravate the floodbecause the arid ground does not absorb water either.) Before this series of storms made landfall, some of California’s reservoirs were nearly exhausted. dry up. Now statewide reservoir storage is near historical average. That’s how this rain is epic.
Snowpack is also very important. It grows at high altitudes during winter, then melts and powers reservoirs as temperatures rise. But climate models predict that a significant portion of the state’s ice will disappear by 2100, said Andrew Fisher, who runs the University of California, Santa Cruz’s. Recharge initiativeResearch on groundwater resources. “Some of the models say it all,” Fisher adds. “Let that sink in for a second. That’s more water than all the dams in the state. That’s sad because there’s no way we’re going to double the number of dams.”
To provide water for people and agriculture, California is step up efforts to conserve watersuch as adding more low-flow toilets into the home and pay people to rip their lawnsthat’s terrible for all kinds of reasons besides their thirst. It’s recycling wastewater from households and businesses into ultrapure water you can actually drink. But most of all, it is trying to keep its sporadic rainfall, instead of draining it, building the infrastructure to generate it.”sponge city.” They are popping up all over the world; concept has been Widely deployed in Chinaand city planners in places like Berlin in Germany and Auckland in New Zealand are using it to deal with greater rainfall.
