The Zone 7 Water Agency board will decide whether to give its sign of support for a $15 billion statewide water project at its meeting tonight.

The board, which regulates the organization that sells water to Tri-Valley cities including Pleasanton, will vote whether to approve a resolution supporting the California WaterFix, a proposal to create large underground pipes to funnel water from the Sierras to participating agencies more reliably than the current infrastructure.