Groundwater Sustainability Plan up for review

Sonoma County’s three Groundwater Sustainability Agencies – in Petaluma Valley, Sonoma Valley and Santa Rosa Plain – released their Final Draft Groundwater Sustainability Plans (GSPs) on October 1, and now they’re hoping the public pays attention.

There virtual community meetings have been scheduled in the next couple week to make sure their findings are heard, and the public has a chance to offer feedback in the process. The one for the Sonoma Valley GSA will take place Tuesday, Oct. 12, from 5:30-7:30 p.m. via Zoom.

Until 2015, when the state’s Sustainable Groundwater Management Act (SGMA) became law, California was the only western state that did not manage groundwater. The law was enacted during the drought of that period – a drought that has returned in the last two years – when some groundwater basins were rapidly being depleted and communities were left without drinking water. The SGMA requires proactive protection of groundwater basins at the local level to ensure that high-quality water is available for people, farms and wildlife now and into the future.

The three GSAs in Sonoma County, focusing on the drainages where groundwater was thought to be at risk, including the Sonoma Valley as well as the Santa Rosa Plain and Petaluma Valley, were all formed in 2017. They have each been studying the present conditions of the groundwater basin, analyzing the basin’s sustainability over a 50-year period, and identifying projects and actions needed to ensure the basin is sustainable by 2042.

The draft groundwater Sustainability Plan that was issued this week presents findings that are concerning: “the amount of groundwater stored in the aquifers is declining on average by about 900 acre-feet per year … there are some locally limited human-caused impacts on groundwater quality from land-use activities, such as agriculture, commercial, industrial, septic systems, and wastewater treatment facilities; (and) limited data indicate possible inland movement of brackish water” at the marshlands where the Valley meets the San Pablo Bay.

The plan does offer some management proposals, including voluntary reductions in groundwater use in domestic, agricultural, commercial, and industrial sectors use through water conservation tools; expansion of recycled water in Sonoma from the reclamation site on south Eighth Street East; and expanded study of and prioritization of other policy options.

Underlying the entire draft report is the intriguing long-term climate forecast upon which the plans are based: “The climate change scenario … simulation provides for several very dry years through 2025, normal and wetter years through 2050, and then a long-term drought after the mid-twenty-first century. This climate scenario allows for a significant stress test for groundwater resources planning during the GSP implementation horizon.”

The final Draft Groundwater Sustainability Plan can be viewed online by going to sonomavalleygroundwater.org, or reviewed in hard copy at Sonoma Valley Regional Library, 755 W. Napa St.

Those interested in participating in the Oct. 12 review of the draft plan must RSVP online by at the same link, sonomavalleygroundwater.org.