If you wanted to find an issue that illustrated the complexity and the controversy that can come with water in the western United States, you might want to have huge cities fighting farmers over water supplies, enormous infrastructure already built and more planned, massive pumps providing transbasin diversions, and a fish about the size of your finger throwing a wrench in all of that. Well, it just so happens we have the California Bay Delta to provide us with just that issue. So what are we talking about? First let's orient ourselves. Here's California and the Central Valley. The Central Valley is a large flat area in the middle of California that's probably the most valuable farming area in the United States. As you can see in this map, most of the States rivers drain into the Central Valley. They come together to form the Sacramento River descending down from the North, and the San Joaquin River descending up from the South. Those two come together in a natural estuary that's called the Sacramento San Joaquin Bay Delta or more commonly just the California Bay Delta. This is actually a fairly unusual natural place because it's an inland delta. So most of the time we're familiar with rivers ending with their mouth at the sea spreading outwards, dropping their sediment load to create this wide fan-shaped delta. Well, what happens in the California Bay Delta is that there's only a small outlet for the water from these rivers through the San Pablo Bay and the San Francisco Bay to allow that water to get out into the Pacific. So instead, there's actually a delta that forms going inland from those bays towards the inland portion of the State and into the Central Valley. Naturally, this area is an estuary. So an area with mixed fresh and salt water, lots of marshland, lots of wetlands, and lots of wildlife. But since about the mid 1800s, farmers have been putting up levees around some of the land, draining the land, and creating farmland out of it. What we've resulted in is some of the most valuable farmland in the United States sitting there on these man-made islands really formally called polders held back from the water. One more important detail is that the delta is well below sea level. As you can see in this map just how low it is, up to about 20 feet below sea level. Notice that this map is in meters, but up to about 20 feet below sea level is some of this land and it's actually been subsiding or dropping down as farmers drain it. That has a number of consequences but one of the consequences that we'll explore a little further, is that an earthquake in the wrong place could result in salt water inundation of much of the States water supply. So let's take a look at storage and conveyance in California. We've already alluded to just how much there is. Here you can see the circles representing reservoirs of different sizes, and the dotted lines showing us all of the different conveyance structures mostly canals. Most of the water in California is all directed into the delta. So a lot of that water comes into the delta from the North, and from the East it's often snowmelt in the mountains. Then it's drawn from the southern portion of the delta down towards Southern California particularly the greater Los Angeles area. What that does is it sets up a perfect collision of interests between the Southern California area with tremendous population that wants water for cities, and the delta residents as well as the Central Valley where there's a lot of irrigation need for farming. That's really at the heart of the story of California's water conflicts. One of the biggest fights related to the delta has centered around a proposal that was originally thought up in the 1940s and that's to create something called a Peripheral canal. The Peripheral canal would be a canal about 40 miles long, allowing water to go directly from the Sacramento River around the delta and into the intake for where it's going down to Southern California. So that would allow the water to be sent directly without it having to be drawn out of the estuary. You can see in this map over here three possible alignments of such a canal. One of the biggest driving factors for creating such a canal would be because low flows due to all the water use in the area have resulted in low water quality going to Southern California. So the idea would be to take that higher-quality water before it gets to the delta and send it directly to Southern California. But, voters have already rejected a plan to do such a thing. In fact in 1982, voters voted down the proposal that would build such a canal. However, this is the west and projects like this rarely ever die. So now California is considering instead tunnels that would go underneath the delta at a cost of perhaps at least $15 billion doing the same thing but with tunnels going underneath the delta, two tunnels, four stories tall each taking that water and sending it to Southern California. A lot of people in Southern California favor this because it would really deliver them that high-quality water that they're looking for. But then you've got delta residents and you've got farmers in the region who oppose it because they think that's going to take water away from their availability to use it, and adding to the mix you've got environmentalists who also oppose taking water out of the natural delta environment. Their interest is in trying to have as much of the original estuary environment intact as possible. Then into this comes the delta smelt. So the delta smelt is a fish native to the delta, and it only gets up to about the size of your fingers. So at its maximum may be a little bit less than three inches long. The delta smelt is pretty much gone from the southern portion of the delta because of the removal of water from the delta over time, so it's been declared endangered. You might remember from an earlier video where we talked about the Endangered Species Act, as something that can actually have a powerful influence over what happens with water in the western United States. Because the Endangered Species Act says that the federal government needs to be able to try to recover endangered species, and that can include creating the habitat necessary to do so. So what has happened with the delta smelt, is that the government has repeatedly tried to figure out how to provide enough water for the fish to recover. Its been fought over in courts among the various interests, but the courts have generally found that water needs to be provided for the smelt to be able to survive there, and that water has to come at the expense of some unusually farms in the delta, which is one of the reasons it's been so controversial. What does all this mean for the future? Probably more of the same. So again, this is an issue that's maybe at least a 100 years old. The same fights, we've been talking about the same infrastructure project for going on almost 80 years now. Meanwhile at anytime an earthquake could occur. An earthquake could rupture many of the levees in the area and allow saltwater from the base to intrude into the delta which would really change the water quality and potentially disrupt a lot of the water supply heading towards Southern California. In addition, we know the land is subsiding, a continued problem making it more and more vulnerable to inundation in a lot of possible situations. Add up onto that climate change. I talked about climate change in a video in a previous module, California maybe drying up due to climate change or it may just be experiencing more and more extended drought. We know it's getting hotter, we know evapotranspiration is going up, crop demands for water are going up. That's going to stress this entire thing. So we've got lots of demands, we've got tiny supplies, we've got serious controversy, and we've got big money involved. It's a classic case of water in the Western United States, and it's something to keep a close eye on. I recommend you check out some of the extra resources we provide in our links. Thanks again for watching. See you in another video.
