In the world of California water, much of the conversation – nay, argument, really, centers around this place called the Delta. Northern Californians think Southern Californians want to drain it dry. Southern Californians, for the most part, don’t even know where the Delta is, much less why it would be important to them. I’m just guessing, but I would be willing to bet that most Californians who don’t live near the Delta don’t know where it is or why it is important, either.
So in this post, using pictures of my own and borrowing a few pictures from others, I will try and answer the question, what is the Delta and why is it important?
This photoblog post has been polished up and turned into a flash slideshow which you can see by clicking here. Or you can click on the “Read the rest of the page” link below to read the photoblog post.
First of all, let’s take a look at where the Delta is.
The Delta encompasses 738,000 acres, stretching inland from Antioch to Stockton, and includes portions of Sacramento and West Sacramento at its northern point down to Tracy at its southern point.
Five rivers flow into the Delta, accounting for nearly half of the snowmelt and runoff of the entire state. Because the Delta is connected to San Francisco Bay, and thus to the ocean, it is affected by tidal action. Although the Delta, for the most part, remains freshwater, this tidal action affects the depth of the waterways. There are approximately two high tides and two low tides every day (photo by USGS.)
Once a vast marsh, unsuccessful miners turned to farming and began draining and reclaiming the land in the mid 1800s, encouraged by federal swampland reclamation laws and the Delta’s rich, fertile peat soil. Levees were built, creating islands of productive farms. The reclamation of the marshy Delta progressed steadily for many decades, and was pretty much complete by the 1930s (photo from WikiMedia.)
This is what the Delta looks like today from above. It is a maze of over 1100 miles of waterways that traverse prime farmland and natural habitat areas, with levees surrounding numerous islands.
Some islands are only accessible by boat (photo by DWR),
some of these islands are only accessible by ferry,
while others are connected by drawbridges and bridges.
There are a lot of bridges in the Delta,
bridges of many different types and colors.
The Delta is an estuary, which is the body of water that is formed when freshwater from rivers and streams meets the ocean and mixes with the salty sea water, creating a vibrant and unique ecosystem (photo by DWR).
The California Delta, in conjunction with the San Francisco, San Pablo and Suisun Bays, is the largest estuary on the Pacific Coast, and is home to over 750 plant and animal species (photo by USGS/WikiMedia.)
The Delta is home to a vibrant diversity of wildlife and birds (photo by DWR),
including millions of migratory birds and ducks who stop over on one of the last remaining wetland areas on the California coast. (photo by Peter Baer, flickr.)
The Delta supports a vibrant fishery for both recreation and commercial purposes. Eighty percent of the state’s commercial fishery species either live in or migrate through the Delta, including four Chinook salmon runs, sturgeon, stripers, and bass (photo by USFWS, flickr).
There are numerous opportunities for recreation in the Delta. The labyrinth of the sloughs and waterways of the Delta make it a prime place for boating and waterskiing.
There are over 100 marinas and waterside resorts, RV Parks, grocery stores and dock-side restaurants (photo by DWR).
The Delta's frequent winds make for ideal sailing and windsurfing conditions.
Fishing is popular here, too.
The Delta’s islands are, for the most part, sparsely populated (photo by DWR).
You can seemingly drive for miles on winding levee roads and not encounter another soul.
It is a wonderously peaceful place.
Inside the Delta, there are small villages and towns (photo by DWR),
many have been here since the beginning (photo by DWR).
However, increasingly, modern urbanization is occurring inside the Delta. (photo by DWR.)
But the main land use by far in the Delta is and always has been agriculture (photo by DWR).
Most of the islands in the Delta are used for farming, many of which have been held in the family for generations.
The Delta’s rich, fertile soil supports one of the most productive agricultural regions in the world.
Over 90 agricultural products are grown in the Delta,
which includes crops such as corn, grain, alfalfa, rice, tree fruits, nuts,
grapes, strawberries, blueberries, olives, tomatoes, asparagus, and more.
Since the Delta occupies the space between the Bay Area and the rest of the state, a lot of critical infrastructure must cross the Delta. Two major highways, I-5 & SR-99, cross the Delta on its periphery, and state highways 4 and 12 connect the Central Valley to the Bay Area (photo by DWR).
Three major railway lines run through the Delta,
and ships access the inland ports at Sacramento and Stockton through the deep water ship channels, traveling nearly 80 nautical miles inland from the Golden Gate Bridge (photo by DWR).
The Delta is a vital link in the state’s utility infrastructure as well. Natural gas was discovered in the Delta in 1935, and today, the Delta serves as an important source of natural gas and as an important underground gas storage area.
Electrical transmission lines cross the Delta, some bringing power to the Bay Area, and others carrying power southward to the cities and farm of Central and Southern California.
There are many wind turbines here, positioned to take advantage of the frequent and reliable winds (photo by DWR).
But perhaps the most critical infrastructure function of the Delta is acting as the hub for the state’s water system, channeling the freshwater from the mountains to reach the pumps of the state and federal water projects. Shown here is a photo of Banks Pumping Plant, which draws water from the Delta for the State Water Project. This is the start point for the California Aqueduct, seen at the very top (photo by DWR).
The pumps draw water and send it south to irrigate the farmlands of the San Joaquin Valley, as well as to feed the faucets of Southern California. Shown here is of the Bill Jones Pumping Plant, which draws water for the Central Valley Project.
There are others who draw freshwater out of the Delta, too. Municipalities and farmers living within the Delta also draw water directly from the Delta.
And the Mokelumne Aqueduct and the Hetch Hetchy system carry water that would otherwise flow into the Delta across it to quench the thirst of the Bay Area communities.
All in all, about two-thirds of the state's population and millions of acres of farmland are dependent upon the Delta, at least in part, for their water. Many more affect the Delta by drawing water upstream, taking water that would have otherwise flowed into the Delta.
Freshwater flows are needed to keep the saltwater from intruding into the Delta, and to flush drainage and pollutants out. The biggest argument is over how much water can be drawn the from the Delta and still have a healthy ecosystem. Nobody can really agree on how much can be drawn or who should be forced to take less.
And while the Delta is a beautiful and peaceful place, it's delicate ecosystem is in trouble.
The Delta looks nothing like it used to look like before it was remade to suit the white man’s purposes, and so, not surprisingly, native species have struggled to adapt. Some native species have already gone extinct, and several more are endangered, including the spring-run and winter-run Chinook salmon, and the Delta smelt (photo by the USFWS, via flickr).
Operations at the water projects have been subjected to limits and shutdowns imposed by the court in order to protect endangered species (photo of Skinner Fish Facility by DWR).
While certainly the existing water-supply operations have had profound impacts on the Delta, changing the natural flow patterns and even reversing the direction of the rivers at times, there are many other potential factors involved in the Delta's ecosystem collapse.
The Delta estuary has been named as one of the most invaded estuaries, with over 250 non-native plants and species now flourishing, much to the detriment of the native ones (photo by DWR).
Water quality within the Delta is a big issue. An extensive network of drainage ditches keeps the Delta islands from flooding. Many farms are allowed to discharge this drainage directly into the Delta, flushing pesticides and fertilizers into the waterways.
And there are municipalities that discharge their treated wastewater into the Delta. Recently, Sacramento was ordered to upgrade it's treatment plant to remove more waste products from its effluent.
No one can agree on just what is causing the collapse of the ecosystem: excessive water diversions? invasive plants or species? ag drainage & pollutants? or something else? These problems needs to be solved if water exports are going to continue.
The state of California mandated in 2009 legislation that the goals of ecosystem restoration and water supply reliability must be treated equally, not one favored over the other. The courts have already intervened in the water supply operations; it is increasingly apparent that if the state cannot solve the problems in the Delta, there will only be more court intervention in the future.
Another major concern are the condition of the levees. In the Delta, the levees have the dual purpose of providing flood control and acting as channels for conveying water to the pumps in the Southern Delta for export to the San Joaquin Valley and Southern California.
Many of the levees still in use today were built in the Gold Rush days; they are not built up to modern engineering standards and must be periodically raised and strengthened (photo by DWR).
Levee failures are rather common; since the Delta has been reclaimed, each of the islands and tracts has flooded at least once, several of them more than once. There have been about 100 levee failures since the early 1890s (photo by DWR).
Damage to the flooded islands can cause extensive property damage; these events will only get costlier as development continues inside the Delta (photo by DWR).
Fixing the levee requires first rebuilding the broken portion of the levee (photo by DWR),
and then pumping the island dry. It's an expensive process for the property owners; several of the flooded islands have been simply been abandoned (photo by DWR).
Most of the Delta islands are sinking at a rate of 1 to 3 inches per year, with many islands already between 10 to 25 feet below sea level. The dominant cause of this subsidence is the decomposition of organic material in the rich peat soil. This subsidence increases the pressure on the aging levees (Diagram by the USGS.)
In this picture of Twitchell Island, you can see how much lower the land is compared to the level of water in the channel (photo of Twitchell Island by DWR).
Several earthquake faults run under the Delta, and seismic risk to the levees is a major concern (Shhh! Map ripped off from someone's presentation...) A massive earthquake could cause multiple levee failures simultaneously, flooding numerous islands and drawing salty water from San Francisco Bay deep into the Delta; this could jeopardize the fresh water flows that much of California's population and agriculture depends on. It would cost billions and take anywhere from 6 months to 2 years to repair.
Add in the effects of climate change - rising sea levels and more extreme events, and it seems quite likely the Delta of the future won't look like the Delta of today (photo by DWR).
People have been fighting over the Delta for years: farmers (both inside and outside the Delta), fishermen, environmentalists, state and federal agencies, water agencies and Delta residents.
Many attempts at problem solving have met with dismal failure. Everyone pretty much agrees there are problems; but no one can really agree on the extent of those problems or what exactly should be done about them (photo by DWR).
So there you have it, the Delta in a nutshell, although the story is quite complex and there’s a lot more to it than can be covered in this simple post. So here are some links for further exploration of the Delta:
Why the Delta matters to every Californian, my own article from Aquafornia’s information desk
Sacramento-San Joaquin Delta: The sinking heart of the state, by the USGS
Comparing Futures for the Sacramento-San Joaquin Delta, by the PPIC: Jay Lund, Ellen Hanak, William Fleenor, William Bennett, Richard Howitt, Jeffrey Mount, and Peter Moyle; July 2008
The Delta Stewardship Council website, a wealth of information on the Delta, including the latest on the Council’s Delta Plan
The Bay-Delta Conservation Plan, a multi-agency planning effort currently underway
The Discover the Delta Foundation, a project dedicated to teaching people about the Delta and its resources.
The Bay Institute’s Rivers and Delta, an environmental research and advocacy group
California Delta Chambers and Visitor’s Bureau, find out more about visiting the Delta
Note about the pictures: Pictures that are not credited are my own. You can see even more of my Delta pictures here: http://www.flickr.com/photos/aquafornia/sets/72157604411233754/