Santa Lucia Highlands Vineyards: Terraces, the River Road Corridor, Groundwater and Boundaries

By Matthew Martinez, Founder, CEO & Managing Broker, Diamond Real Estate Group. California DRE #01869679.

The Santa Lucia Highlands AVA is a band of east-facing alluvial fans and terraces on the west side of the Salinas Valley, running roughly from the Chualar area past Gonzales toward Soledad, below the Santa Lucia Range. It is a farming landscape more than a residential one: blocks are large, slopes are gentle to moderate, water comes from the Salinas Valley groundwater basin, and Monterey County has just adopted new rules for wineries along River Road. Those factors, plus a federal boundary that TTB trimmed in 2021, are what a buyer or seller needs to understand first.

Santa Lucia Highlands at a glance

Where the appellation runs

The current rule at 27 CFR 9.139 begins where Limekiln Creek crosses the 360-foot contour on the Chualar quadrangle. On the valley side it follows low contours (120, 110 and 160 feet), River Road, the Salinas River and Foothill Road to the Paraiso Road junction near Soledad. It then runs south on Paraiso Road toward Clark Road and the historical line of the Arroyo Seco Land Grant before turning back north along section lines high on the Santa Lucia Range. Because the eastern edge sits on contours a few dozen feet apart, a ranch that runs from River Road down toward the river can have blocks on both sides of the line.

The TTB AVA list places Santa Lucia Highlands within the Monterey and Central Coast appellations. To the south and east it borders Arroyo Seco, another Monterey sub-AVA, and the two boundaries were adjusted together.

The 2021 boundary change

TTB’s final rule T.D. TTB-172, effective September 24, 2021, made two changes. It removed about 376 acres at the northern end that lie in the Salinas River floodplain, are nearly flat and have sandy, low-organic soils unlike the rest of the Highlands; that land remains in the Monterey and Central Coast AVAs. It also moved about 148 acres of east-facing alluvial fan from the western side of Arroyo Seco into the southeastern Highlands, affecting one vineyard of roughly 135 acres of vines. If a listing or a grape contract references the Highlands name, check that the blocks fall inside the post-2021 line. The rule also describes the appellation’s typical landform: east-facing fans and terraces with slopes of 5 to 30 percent, with Chualar loams the most common soil.

For the wider regional context see our California wine regions guide and the Monterey County vineyards page.

Winery rules: the River Road corridor

The Highlands lie along River Road, one of three corridors in Monterey County’s Agricultural and Winery Corridor Plan (AWCP), a part of the 2010 General Plan. According to the county’s legislative file, the corridors are River Road, Jolon Road and Metz Road, spread across the Toro, Central Salinas Valley and South County planning areas. The AWCP works as a combining district laid over existing zoning, and it introduces a zoning clearance: a ministerial approval for qualifying AWCP uses that meet objective design standards (section 21.51.080), reviewed by the Chief of Planning. Large events of 500 or more people need a Special Winery Related Event Permit under section 21.51.100. The Planning Commission recommended approval on August 12, 2026.

The Board of Supervisors order shows Ordinance 5453 adopted 5-0 on September 29, 2026, adding Chapter 21.51 (the AWCP district) and Chapter 21.71 (zoning clearance) to the zoning code. The Board also directed staff to come back within 90 days with options on square-footage flexibility, so expect follow-up changes. Because the rules are brand new, confirm with Monterey County Housing and Community Development exactly which winery, tasting and event uses a specific River Road parcel can obtain, and how any existing permit fits the new district.

County approval is only one layer. A winery also needs a California ABC license and a TTB wine premises permit; see winery license transfer, how to start a winery and winery wastewater.

Water: the Salinas Valley groundwater basin

Highlands vineyards are irrigated from wells, and the Salinas Valley groundwater basin is managed in subbasins under SGMA. The Salinas Valley Basin Groundwater Sustainability Agency, formed in 2017, is working toward basin sustainability by 2040 according to its website. The northern part of the valley, the 180/400-Foot Aquifer subbasin (basin 3-004.01), is designated critically overdrafted. DWR approved its sustainability plan on June 3, 2021, with recommended corrective actions, and the DWR assessment (copy hosted by the California Water Library) estimates seawater intrusion at about 10,500 acre-feet a year.

Which subbasin a Highlands parcel overlies, and therefore which plan, fees and reporting apply, depends on location along the valley; check it on DWR’s basin prioritization map and the SGMA portal. Then review well logs, pump tests, water quality and any agency extraction reporting. A regional plan approval does not guarantee a given ranch’s supply. Read vineyard water rights and our Monterey County water use and property plans guide.

Flood, fire and contracts

The 2021 TTB rule itself describes the Salinas River floodplain at the valley’s edge, which is why the lowest ground was cut out of the AVA. Ranches that reach toward the river should be checked on FEMA’s flood maps for structures, wells and pumps.

Upslope, the Highlands back onto the brush and woodland of the Santa Lucia Range. CAL FIRE’s Fire Hazard Severity Zone maps rate land as Moderate, High or Very High; the State Responsibility Area maps took effect April 1, 2024. Look up each parcel and price insurance early. See wildfire smoke taint and vineyard and winery insurance.

Much Salinas Valley farmland is under Williamson Act contracts. The Department of Conservation notes that contracts bind later buyers, renew annually on 10-year rolling terms (20 years for Farmland Security Zones), and can be ended early only through a landowner-initiated cancellation with a 12.5% fee. Where fruit is sold under contract, read the grape agreement and any lease before closing; see grape purchase agreements and vineyard leases.

A due diligence list for a Santa Lucia Highlands vineyard

• Map every block against the post-2021 27 CFR 9.139 line, especially near River Road, the northern floodplain and the Arroyo Seco edge.
• Confirm that any grape contract, label or marketing that uses the Highlands name matches the blocks that actually qualify.
• Identify the groundwater subbasin and its sustainability agency; collect well logs, pump tests, extraction reports and water quality data.
• Ask Monterey County how the new AWCP combining district and zoning clearance apply to the parcel and to any existing winery permit.
• List every county permit, ABC license and TTB permit behind current winery, tasting or event activity.
• Check FEMA flood zones for structures, wells and pump stations on the river side.
• Check the CAL FIRE hazard zone for upslope parcels and road access for fire equipment.
• Obtain any recorded Williamson Act or Farmland Security Zone contract.
• Review grape contracts, lease terms, vine age, rootstock and trellis condition.
• Work through the vineyard due diligence checklist.

Questions people ask

Sources & notes

1. 27 CFR 9.139 Santa Lucia Highlands, 2025 CFR edition via GovInfo (current text at eCFR Part 9)
2. TTB final rule: T.D. TTB-172, Modification of the Santa Lucia Highlands and Arroyo Seco boundaries, 86 FR 47377 (Aug. 25, 2021)
3. TTB: Established American Viticultural Areas
4. County of Monterey: Agricultural and Winery Corridor Plan ordinance, legislative file
5. County of Monterey Board of Supervisors: Board order, Ordinance 5453
6. Salinas Valley Basin Groundwater Sustainability Agency: Agency home page
7. DWR: 180/400-Foot Aquifer Subbasin GSP assessment, June 3, 2021 (copy hosted by the California Water Library)
8. DWR: Basin prioritization and SGMA portal
9. CAL FIRE Office of the State Fire Marshal: Fire Hazard Severity Zones
10. California Department of Conservation: Williamson Act questions and answers

General information, not legal or tax advice. Last reviewed November 2026 by Matthew Martinez.

Related: Monterey County vineyards · Gonzales real estate guide · Soledad real estate guide · Monterey County land and ranches · Santa Cruz Mountains vineyards · Vineyard due diligence · Vineyard water rights · All vineyard and winery guides