How WELL do you know the Santa Rosa Plain GSA subbasin?

Location: bounded by Sonoma Mountain and Mayacamas Mountains on the east and the Mendocino Range on the west

• ~22 miles: distance of the basin from north at Healdsburg to the south at Cotati
• ~9 miles: distance east to west at the widest point

Principal sources of groundwater recharge: precipitation and infiltration from streams

80,000 acres: land covered by the subbasin, including Town of Windsor, Cities of Cotati, Rohnert Park, Santa Rosa, Sebastopol and unincorporated rural areas

• 36% Urban community areas
• 26% Agricultural areas
• 35% Native vegetation and surface water
• 3% Classified as ‘vacant’

Acreage by crop types in the subbasin (all water sources, not limited to groundwater-irrigation)

• Citrus & subtropical: 15.8 acres
• Deciduous fruits & nuts: 141.4 acres
• Grain: 2,777.1 acres
• Pasture: 2482.7 acres
• Truck nursery & berry: 559.3 acres
• Vineyard: 9072.8 acres
• Idle or unknown: 462.7 acres
• Turf irrigation: 593 acres

1,499 acre-feet: Estimated groundwater crop irrigation offset per year by alternative water sources (recycled water, surface water)

81,951: number of parcels in the subbasin

8,650: approximate number of groundwater dependent parcels (note, these numbers do not include those connected to a public water system, and some parcels have more than one use)

• 6721: Residential
• 498: Commercial
• 937: Agricultural
• 129: Turf

32,000: number of people in Santa Rosa Plain that rely solely on groundwater for drinking and other basic water needs.

4,000-5,500 estimated number of domestic wells in the Santa Rosa Plain subbasin

< 200 ft: depth of most wells in the shallow aquifer

~ 200-800 ft: typical depth of wells in the deep aquifer

113: number of groundwater-level monitoring wells located in the subbasin and contributing watershed

Status of Conditions

Status of Conditions defined by the Sustainable Groundwater Management Act that the GSA is actively addressing via the implementation of projects and programs in the Groundwater Sustainability Plan:

• Land Subsidence: no evidence for concerns
• Groundwater quality: no evidence for concerns
• Interconnected surface water: more data needed
• Reduction of storage: generally stable, potential for future declines
• Lowering of groundwater levels: generally stable, limited areas of declines

Want to learn more?

Visit our website to access the Groundwater Sustainability Plan and find detailed information on the status of this work to manage groundwater resources in our Annual Report.

Join in the community-wide effort to support sustainable groundwater with one of our community programs:

LEVEL UP! – Voluntary Well Monitoring, Flow Smart – Voluntary Flow – Metering, and Well Aware – tools for building local groundwater sustainability.

SantaRosaPlainGroundwater.org