After years of planning, officials have finalized all 97,000 pages of environmental documents to support Gov. Jerry Brown’s controversial plan to build two massive tunnels through the heart of the Sacramento-San Joaquin Delta. In spite of a recent call for a scaled-down version of the project from a prominent nonpartisan California water think-tank, state officials are moving forward with the original plan for what they call California WaterFix. The $15.5 billion project would tunnel two pipes 40 feet in diameter for 35 miles under the fragile ecosystem that serves as the hub of the state’s water-delivery network.