Here's how two giant, gravity-powered water tunnels could protect California from drought!

California's current drought crisis isn't going away any time soon, and state authorities have cast their nets far and wide looking for any way of conserving what little water they have left. Now California Governor Jerry Brown has unveiled new details of a plan for two huge pipes, powered by gravity, to improve the flow of water around the Sunshine State.

The major infrastructure project is called the California Water Fix, and it turns the current system on its head. The pumps and gates in place today drag saltwater and fish into the San Joaquin Delta from the ocean while trying to take freshwater out, but the newly proposed system is going to use freshwater from the north instead, bypassing the Delta completely with the help of these two massive pipes, each 12 metres (40 feet) in diameter.

These pipes are going to start collecting water upriver, which means they can be powered by the natural force of gravity as the water flows down towards the ocean. They'll also be fortified against the threat of an earthquake, and won't be affected by any change in sea level off the west coast of the US - unfortunately,climate change is now an important consideration for any new infrastructure system.

The new plan is not without its opponents: activists are campaigning to save the ecosystem of Delta, arguing that diverting freshwater away from the estuary will have devastating effects on the wildlife and the health of residents in the area, as there will no longer be any natural flushing away of the saltwater in the Delta region.

Everyone agrees that the existing system of pumps is antiquated and needs replacing, but there's a difference of opinion about how to fix it.

Essentially, the California Water Fix initiative will catch freshwater before it reaches the Delta, rather than pulling it from the Delta afterwards (and thus pulling in saltwater from the sea at the same time). The local authorities are now investigating in more detail what the impact on local wildlife species and the Delta ecosystem might be.

"We can't just cross our fingers, hoping for the best in the Delta," Governor Brown said at a press event when the plans were first presented last year. "Fish populations are at an all-time low. Bold action is imperative. We've listened to the public and carefully studied the science. This revised plan is the absolute best path forward."

In the recently given State of the State address, Governor Brown said the plans represented "a solid program" to tackle the drought water wastage in the longer-term. "Our goal must be to preserve California's natural beauty and ensure a vibrant economy - on our farms, in our cities and for all the people who live here," he said.