A Bay Area water agency agreed Tuesday to pump $650 million into Gov. Jerry Brown’s Delta tunnels project, providing a meaningful boost for the controversial $16.7 billion plan. The 4-3 vote by the Santa Clara Valley Water District brings the tunnels project, which would overhaul the troubled heart of California’s aging water delivery network, a step closer to being fully funded. Just a few months ago the project, officially known as California WaterFix, was sputtering for a lack of funds.