To meet mandates of the Sustainable Groundwater Management Act, three options have emerged to achieve groundwater sustainability. In August, the board of the Salinas Valley Basin Groundwater Sustainability Agency will select one of these portfolios to recommend to the state’s Department of Water Resources for review. A hurdle is the cost.
“We’ve had some real struggles,” Advisory Committee Chair Curtis Weeks told the board on July 9. “They see a number and they can’t talk about the merits of the project.”
The project portfolios all incorporate some amount of demand management (reduction in pumping), optimization of the Castroville Seawater Intrusion Project, and use of a Monterey County Water Resources Agency permit to divert water from the Salinas River.
Both Portfolios 1 and 3A utilize a brackish groundwater restoration project (BGRP), each at different scales, affecting both cost and outcome.
Portfolio 1, the most expensive option, projects $1.3 billion in capital costs and $117 million in annual operating costs. It includes a large-scale BGRP, Salinas River recharge in Castroville and the East Side subbasins, CSIP improvements and 10-percent demand management.
Portfolio 3A would be $1 billion with annual operating costs of $74 million. It would scale back BGRP and add infrastructure to deliver treated water to Salinas, Marina and Castroville to reduce urban pumping.
Portfolio 4 is considered the low-cost option with an estimated $600 million in capital costs and $8 million in annual operating costs. It has the highest demand management, at 20 percent.
Portfolio 1 would meet seawater intrusion targets by 2040 and 2042, while Portfolio 3A reaches them over a longer period, according to technical consultant Derrik Williams. Portfolio 4 would not meet state requirements.
“It’s a hard puzzle,” says Piret Harmon, SVBGSA’s manager. “We could just pick a project that works for seawater intrusion in 180/400 Subbasin and not worry about the others, but the holistic approach in the end will [be] the most cost-effective.”