Making the Most of Flooding and Learning for the Future
Updated: Apr 5
California flooding, San Francisco Chronicle reporting
In January, we were reminded of California’s climate predicament: to be living amidst the twin risks of flood and drought simultaneously. Increasing ocean and atmospheric temperatures drives more energy and water vapor into our storms, while also creating more potential for deeper droughts.
What these successive atmospheric rivers highlight is that more of California’s precipitation will
arrive as rain than snow, and in greater concentrations. So how can California, and other places
in the world with torrential downpours and monsoons, make the most of these plentiful water
opportunities? How can groundwater basins be replenished? What will prevent sewer systems
from being overwhelmed? What information is needed to better predict and manage future
atmospheric river events?
The traditional, reflexive response was to build more dams. In the U.S., however, dams have
already been built wherever they were feasible–400,000 dams at last count, of which 85% are
“unnecessary, harmful or dangerous.” So let’s put the discussion of dams aside, except in the
effort to remove 30,000 of the worst, and say that no new dams will be developed. (American
Map of 90,000+ dams in the United States. National Inventory of Dams.
So what should we do to capture water in the deluges to better manage and save water during the rainy days and store water for later? Here are a few starting points for consideration for households, for cities, and for states.
Homeowners can install on-site rainwater capture. Anyone with a yard or roof can get started capturing, collecting and using rainwater at their home and business. Most practices involve directing rainwater into the garden or capturing rainwater for later use. 55 gallon rain barrels cost less than $100 and can be integrated into irrigating gardens. You don’t need approval or a permit to use water outdoors (except in Colorado over 100 gallons), and it improves climate resilience and reduces your water bill. Home and business owners in the US can find resources at the Surfrider Foundation’s Ocean Friendly Garden program.
Image from Surfrider Foundation Ocean Friendly Garden program.
Cities can develop Green Infrastructure. Some of the urban flooding seen last month has occurred because of the paving or “hardening” of city surfaces with streets, sidewalks and roofs. Where once rain might have seeped and infiltrated into the ground, now rain hits impermeable surfaces and runs off into gutters, sewers and channelized rivers. This municipal infrastructure has modest limits that can get overwhelmed and stop working – essentially blocking excess rainfall from accessing these engineered systems. Solutions can look like rain gardens, bioswales, vegetated road medians, and other systems. Cities can incentivize designing and building green infrastructure and empower property owners to do this themselves by partnering with systems like 3R Water. Financial incentives are important drivers for participation. Los Angeles County’s Safe Clean Water program is the national leader in building a regional program to increase local water supply, replenish groundwater, improve water quality and protect public health. Cities looking to develop green infrastructure projects can rely on the “Tap Into Resilience” program created by the WaterNow Alliance to explore ideas and partner with WaterNow to develop pilot projects.
States can give rivers room to run by reconnecting rivers and floodplains. Flood waters need places to spread out, as they used to do before their banks were straightened and armored with levees. Erica Gies explains in her insightful new book Water Always Wins that “much of the water we see today, especially in industrialized countries, is not in its natural state. Human’s efforts to control it have created giant lakes behind dams; deeply scoured, fast-flowing rivers; straightened, narrow creeks far below their banks; arrow-straight canals that deliver irrigation water to farms…What many of us think of as “river” is a hobbled water canal that no longer wanders across its floodplains, depositing nutrient-rich, land forming silt as it goes.” She argues for adopting a “Slow Water Manifesto.” States should move toward enabling agricultural and rural landowners to allow flood flows on their land to recharge groundwater, to enable plants and animals to thrive in floodplains, and re-establish a semblance of this natural water cycle. Echo River Portfolio company Gybe is aiding The Nature Conservancy to monitor water quality across the Mississippi River Basin, and supporting California’s efforts to restore the Klamath River after its four large dams are removed in 2024.
Water Always Wins book by Erica Gies
By pursuing rainwater capture and flood management strategies at the local, regional and state levels, water can spend more time following its natural course, and can be re-connected with natural processes. Flood risk can be reduced, groundwater basins can be restored, and rivers can live closer to their ecological potential.