Generally speaking, these habitats are the marshes, sand beaches, mudflats and the shallow waters of our rivers and creeks whose soil is saturated with moisture either permanently or seasonally; such areas may also be covered partially or completely by shallow pools of water.

They are also nature’s best defense against climate change and subsequent sea-level rise, because of two important functions they perform: they help reduce the concentrations of greenhouse gases through their ability to sink carbon; and store and regulate water. In other words, they act as sponges absorbing any overflow of water.

The federal government came to understand how biologically productive wetlands are and in 1977 enacted the Clean Water Act, the primary federal law in the US governing water pollution and limiting wetlands destruction. The law also created requirements that if a wetland had to be drained, developers at least had to offset the loss by creating artificial wetlands.

Wetlands have historically been the victim of large-scale draining efforts for real estate development, flooding them for use as recreational lakes or agriculture. Ironically, wetlands absorb and protect the surrounding ecosystem from the polluted run-off coming from the agricultural lands that displaced them.

Since 2000, more than 300 wetland restoration projects have been commissioned, varying in size from the 0.7-acre large 12^th Street Reconstruction Project in Alameda County to more than 13,000 acres being restored as a part of the South Bay Salt Pond Restoration Project in San Mateo County. However, the collective size of the projects (58,889.5 acres across California) is dwarfed when you consider that the state has lost 95 percent of its wetland habitat in the past 125 years.

Worldwide, it is estimated that by 1993 half of the Earth’s wetlands had been drained, according to a report published in the New Scientist.

Below you’ll find a map detailing the restoration projects taking place in the San Francisco Bay Area that shows information of their size, location and construction status.

View Wetland Restoration Projects–Northern California in a larger map

Listen to The Changing Bay radio report online.

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This is one of those environmental stories where one event, seemingly far in the past, can have a surprising ripple effect into the future. Most of us think of the Gold Rush and picture prospectors panning for gold in streams and rivers. But some miners used more industrial techniques like hydraulic mining. Using massive, pressurized hoses, they washed down entire mountainsides to get to the gold. (Check out this clip from the KQED special "Saving the Bay" for more).

As a result, millions of tons of sediment washed into rivers and streams in the Sierra foothills and made its way down to San Francisco Bay.  Amazingly, that process has taken decades, creating a murkier bay in the meantime.  Ten years ago, scientists at the US Geological Survey noticed the bay was clearing. While that can have many causes, scientists believe that the sediment pulse from the Gold Rush had finally worked its way out of the system.

It seems like the story would end there, but sediment has a complex role in the bay. Some ecosystems, especially wetlands, depend on sediment.  Salt marshes are built on every high tide by sediment that gets trapped in the plants.  These wetlands are also continually sinking as the soil settles, so this growth is key for keeping them at the right elevation. Less sediment in the bay means there's less for the wetlands, which could be an issue. But there's one thing that makes it worse: sea level rise. Some estimates say that the bay could rise by 55 inches by the end of the century.  That means sediment will have an increasingly important role in the future, one that state agencies are just starting to plan for.

Listen to The Changing Bay radio report online.

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More than 20 million gallons of raw sewage spilled into California waterways last year, according to the state Department of Water Resources Control Board. That's not counting the partially treated sewage that makes its way into our water from overflows and sewer system malfunctions.

Many big sewer pipes are old, and many of the sewage treatment plants are antiquated. But the biggest problem faced by sewer systems in California is the tiny pipe called the lateral.

That's the pipe that runs from your home to the street, the small pipes under all of our homes that end up joining the bigger sewer pipes. When those pipes develop cracks, water leaks into them.

Storm water itself would not overwhelm a sewage system, because it's designed to be a closed system. Storm water is not supposed to BE in sewer pipes. So in one way, it shouldn't even matter what the weather is like – storm water shouldn't really mix with sewage at all.

But during a rainstorm, water seeps into your broken lateral pipe, and all your neighbors' pipes, and that rainwater mixes with sewage in the sewer pipes, and the volume of water/sewage can actually build up far beyond the capacity of the sewer pipe. And in the same way, thousands and thousands of gallons of water mixed in with the sewage can swamp a treatment plant during a rainstorm.

That's the number one concern of sewage treatment plants now. And the sewer districts need your help.

Those laterals are owned by homeowners. They're on private land, so the district can't just go in there and tear them up to replace or fix them.

However, most sewer districts offer a service where they will inspect your laterals to check for leaks, and many have started programs where the district will help pay the cost of repairing or replacing those pipes.

Sewer systems are run by local municipalities. Most communities have a local sewer district, and officials at the district can help you inspect and fix your lateral pipes.

Listen to the Sewage Spills Increasing radio report online.

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