You can make a difference to the hurt being caused by climate chaos and the great extinction event in your town or your city! How? Reuse, repurpose, and recycle this information. You can push your local politicians to act. It will make a difference!
This is the letter for week 170 of a weekly climate strike that went on for 4 years in front of San Francisco City Hall, beginning early March 2019. For more context, see this story. For an annotated table of contents of the topics for all the strike letters, see this story. Meanwhile…
STRIKE FOR THE PLANET
Who’ll stop the rain?
Reaction Guidelines for Flooding, pt. 1: Precipitation
This is a resource for storm-caused flooding. The goal is to have procedures you can pick up off the shelf and start putting in place when it’s too late to avoid disaster.
Glossary of terms used
flooding
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water or other liquids submerging land that is usually dry
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megadrought
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a prolonged drought lasting two decades (20 years) or longer
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precipitation
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water condensed from the atmosphere, often in the form of rain or snow
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SF will get more extreme flooding
Because warmer air holds more water vapor, hotter temperatures mean an increase in atmospheric water and energy, which means more extreme precipitation events (a lot of rain falling in a very short period of time). Unfortunately, more rain per storm does not produce greater yearly rainfall totals; we can and will see extreme rainfall events and flooding in the middle of a megadrought.
How well is SF set up for this kind of extreme precipitation flooding?
SF already has many flood strategies in place
Due to past flooding events and other emergency situations, San Francisco has the following resources in place and mostly available when precip-caused flooding happens:
- a distribution system to get sandbags out to people before possible flooding events
- the “adoption” of storm drains by locals to keep those storm drains clear
- the dispatching of crews pre-storm to put up flood barriers and clean out catch basins in flood-prone areas
- good emergency broadcast systems
- posted tsunami evacuation routes (useful for flood evacuation as well)
- designated evacuation locations on higher ground
- water rescue equipment and personnel, located mostly on the west side of the city
Are these strategies enough?
If expanded and kept up-to-date, these could take care of the majority of SF’s precip-caused flooding needs. Many of these resources, though, are not well-maintained.
For example, the evacuation centers I personally know have not been restocked or reevaluated for supply needs in over 15 years, and few people in the neighborhoods know where their evacuation centers are. The Tuesday at noon Outdoor Warning System has been down for repair for a few years already. There are loads of storm drains that have not been “adopted” or have been orphaned by people moving out of the city. And other areas of the city that will need water rescue operations in the event of extreme precip flooding do not have those resources readily available.
The strategies listed above all need to be inspected, updated, reevaluated, and restocked yearly. The only one that is regularly looked at is the water rescue equipment and personnel, and only in the context of current rescue needs.
What is needed to get these strategies fully operational?
Lots of communication to the people who live in and work in SF, the allocation and reallocation of resources, and some funding. Specifically, we need:
- updated flood maps
- updated evacuation center information
- updated equipment and consumables at the evacuation centers
- an operating Outdoor Warning System
- an expansion of water rescue equipment placement and training
What else is needed?
Extreme precip, along the lines of inches of rainfall per hour for a few hours, is more than our system as set up can deal with. And, as we are in a megadrought, we cannot afford to waste that water.
This means we need a way to catch and store the water from these events. The lakes in SF will help, but the rivers that have been buried would help a lot, too. Additionally, SF is on an aquifer that could be used to store water if we have a way to keep the water from going down the storm drains. We need a way to route and store water from these events. We don’t have one.
Not bad, right?
This is an example of planning instead of reacting. By planning for flooding events, we can minimize the damage they cause. Of course, this is only for flooding from precipitation. Next week we’ll look at flooding from sea level rise. That, I’m afraid, is a different story.