Grace Peng helps update me on water issues, brilliantly

Ok, so part of my climate change worry about southern California is that the recent fires have freaked me the hell out. But in response to this post about water, Grace Peng wrote an informative comment that she couldn’t post because the comments close after a few days (I’m finding that lessens the “shut yer yap, you bitch” comments but still allows for most commenting.)

I’m grateful Grace took the time to update, so I thought I would post her comment here, as a guest post. Thanks for the taking the time, Grace!!

Grace Peng is a data specialist at the NCAR Research Data Archive.She blogs about water and environment issues at Bad Mom, Good Mom.You may find the water posts particularly useful.

My comments are in parentheses. Everything else is all Grace. She writes.

I read “which would flood low-lying coastal communities.” differently than you did. I read that to mean just a few places like Marina del Rey and areas of Long Beach and Huntington Beach. Most of LA county’s coastline has cliffs so most of our coastal neighborhoods are well above 10 feet. In fact, my Redondo Beach neighborhood is 100′ elevation. Thank-you tectonic uplift!

1a. Fun fact, as the Pacific plate continues to lift up the North American plate along the CA coast, our elevation grows. Unfortunately, we are not growing taller fast enough to outrun sea level change–but every millimeter helps, right? a 30-50% offset in sea level rise is nice.

2. LA and SoCal has been adding residents while TOTAL water use has been flat or declining. Household (indoor) water use is no longer considered a consumptive use. We’ve done that while keeping our local water tables the same or growing it slightly, even during drought years.

We are able to do this because we’ve been adding water recycling capacity. We are the US leaders in water recycling and the envy
of municipalities around North America.

Water independence is possible for the SoCal region if we do some things right (and we’ve made a good start.)

– Making our region permeable so that we let rain soak into the ground instead of flushing out to sea.
– Expand water recycling
– Pay to retrofit old homes of poorer people with water saving fixtures and appliances (like paying to keep super-polluting clunkers off the streets.)
– Replumb our area to reduce leaks
– Greatly reduce landscape water use (but keep green lungs in all parts of the city.) Bel Air does not need more grass or fountains. But South LA does need more grass and water features.
– Adopt a smaller version of the CA Water Plan, with smaller tunnels. We need to replace the CA aqueduct because of sea level rise in the delta, fish, earthquake resistance, and subsidence problems in the Central Valley.

3. The Colorado River Compact does over-allocate the water available. However, states have been very, very cooperative in ‘banking’ water they are not using and letting another state use it when they need it. The CO River states have been acting as a regional re-insurance program for dry years. We are spreading the risk of dry years between UT/CO and CA/NV/AZ/NM.

3a. Already, some water compact entities are moving to flexible ‘water units’ instead of specified acre feet. In Northern CO, ‘Northern Water’ compact water rights holders get a specified water unit (which used to be acre feet.) During wet years, a water unit is ~50% of an acre foot. During dry years, one water unit = one acre foot. During wet years, farmers need less water for irrigation. They use less with the assurance that farmers in a different region will reciprocate when they need the water.

4. Climate models show that we are not going to get less precipitation in the SW. It will be about the same or slightly drier on an annual basis. The big change will be in the timing and the type of storms that will hit us. Think fewer slow, soaking rains and more gushing atmospheric rivers. In the higher elevations and NorCal, they will get more rain and less snow.

Future climate is different, and we have to develop a different infrastructure. But, at least for water, we are an unusually cooperative region with the wealth and knowledge to help ourselves.

Tons of good links to follow:

Thanks so much, Grace!