In California, two giant twin tunnels were recently proposed that would be 4 stories high and run for 35 miles under the Sacramento-San Joaquin River Delta in Northern California. The project would cost S15.7 million and provide water to cities and farms to the south.
One of the reasons for these tunnels, which would dwarf the tunnel under the english channel, is the amount of environmental damage caused by the way water is taken form the Delta today. California's governor is in support of the delta tunnels:
Gov. Jerry Brown is promoting the project that would be paid for by cities and farmers mainly in dry parts of California, including Los Angeles, the country's second-most populous city, and the most productive agricultural region, the San Joaquin Valley. These farmers and water managers who face drought and climate change hope the tunnels will bring them a more reliable water supply.