Photo credit: Randy Pench/The Sacramento Bee via AP
If you are familiar with the weather in California, you know that it’s been ‘variable’ to say the least. Over the past five years, the entire state – 100% - was under drought conditions. Then between October 2016 and February 2017, the state saw almost double the seasonal average for precipitation, causing massive evacuations due to overflowing dams and mudslides. We can attribute this to historical alternation between dry and wet weather. But the cycles are more intense than ever, and scientists do attribute both the increased dry and wet ‘peaks’ to climate change.
In addition to the cycles, the generally warmer temperatures are helping to melt the Sierra Nevada’s snowpack significantly (some predictions say 90%) – releasing much larger amounts of water than usual.
An amplifying aspect to the droughts and flooding is the fact that more and more people are moving into areas which are into the path of the potential floods, and are placing an increased demand on the water supply during droughts.
Although this post will focus on California in the United States, consider that the increased threat of climate change related flooding is global – affecting people in Asia living around the Himalayas, Europeans who reside near the Alps, and South American neighbors of the Andes.
So the question is: how can projects save the day?
Let’s start with the problem statement: Since there are increased ‘peaks and valleys' with respect to flooding and drought, what can be done to capture the excess water and store it for those times when the drought cycle starts?
Reservoirs are not the solution. Given the number of dammed rivers, that just will not work.
Could aquifers be the solution? According to an excellent article in the November, 2017 issue of Scientific American, maybe they could – but it will depend on some pretty impressive projects.
In fact, aquifers have ten times the capacity of the 1,400 reservoirs in the state. Also, if you compare the cost of building a reservoir with storing water underground in an aquifer, the cost of adapting an aquifer is 80% less expensive.
We can think of this idea as undoing what was done over the past decades with the construction of massive dams, reservoirs, aqueducts, canals, levees, and pumps, which the article says, “changed the plumbing of the entire state and caused countless unintended consequences”. A series of projects that are proposed in the article seek to “return, somewhat, to nature’s way”. How would this work? Let land flood, but in a controlled manner. Some of the projects that were undertaken in the past did not have a very long-term view with respect to their objectives. In fact, the article says, “Successful projects start with correcting long-term misunderstandings about basic hydrology”.
Consider the real meaning of an aquifer. An aquifer, the lakes, streams, rivers – all of the surface water above it - are actually the same water. So when surface water looks replenished based on recent resupply (such as the October-February period mentioned above), the aquifer is still heavily depleted from decades of pumping by farmers and municipalities.
Some solution proposals
Three ways to store surplus water are proposed in the article: Recharge Basins, Underground Water Banks, and Controlled Levee Breaks
We’ll provide one example of a project, the Oneto-Denier restoration site in the Cosumnes River Preserve. A short project description: 750 feet of a levee (one that was built over a century by farmers to protect their farmland from flooding) was removed to help the Cosumnes River fill this part of the floodplain when waters run high.
In winter 2016, the project got its first test. Hydrogeologists from UC Davis set up instruments to determine what happened as a result. It turns out that the flooding had recharged groundwater three times more than typical from normal rain and irrigation, in turn replenishing more than 2,000 acre-feet of water, and it also appears that native fish are benefiting from this type of floodplain habitat.
Read about this project directly from the UC Davis site here.
Since not many of our readers are hydrologists, we’ll stick with the main point: whatever you believe to be true about climate change, there is a need for projects, project management, and project managers, to deal with climate-related effects, and it serves us well as a discipline, and you as a career aspirant, to be familiar with the changes that are taking place and the opportunities for projects to serve as solutions, whether it’s in responding to (for example) flooding and droughts, or to work on projects that address the causes of human-induced climate change or pollution. And remember – this is just one of the ‘lines’ of the triple bottom line. We will continue to post about not only ecological but also economic and social aspects as well, keeping true to the theme: People, Planet, Profits, and Projects.