The future size and makeup of the Temecula Valley Wine Country will be debated by the Board of Supervisors Tuesday as board members  consider proposed changes -- opposed by some residents -- to a roughly 19,000- acre chunk of Riverside County.

   The board will hold its second public hearing on the Temecula Valley Wine Country Plan beginning at 1:30 p.m. Nearly 50 people spoke during the previous hearing on Sept. 24, and this afternoon's hearing is also expected to be well-attended. 

   The board will consider whether to approve a general plan amendment that calls for new zoning designations, an extensive network of bicycle and horseback-riding trails and lot sizes for future wineries. 

   During the Sept. 24 meeting, the board, at the urging of Supervisor Jeff Stone, whose district encompasses Temecula, suspended action on the wine country makeover after hearing from speakers concerned about everything from  the definition of a vineyard to the amplification systems that might be allowed on wine club properties. 

   The supervisors sent the wine country plan back to the Riverside County Planning Commission for further vetting and refinement, after which the county's Park District Advisory Committee weighed in, culminating in a few modest revisions that the board will consider following public testimony. 

   According to the county Transportation and Land Management Agency, among  the more substantive changes was a request by nine property owners to remove  13 parcels totaling 192 acres from the project area, while a dozen property owners in possession of 262 acres asked to be included. 

   Under the wine country plan, conceived in 2008, an unincorporated area with boundaries three miles north of the San Diego County line, just east of Temecula, south of Lake Skinner and northwest of Vail Lake, would be broken into four districts: equestrian, existing, residential and winery.

   The area is currently home to 42 vintners. County officials foresee as many as 170 being established in the coming decades.

   ``The purpose of the project is to provide a blueprint for growth to ensure that future development activities will enhance, not impede, the quality of life for existing and future residents, while providing opportunities for continued development and expansion of winery and equestrian operations within this part of the county,'' according to a Transportation and Land Management Agency statement. 

   Preparing the area for expansion will require new infrastructure, more government services and accommodations for existing residents and businesses -- all of which pose challenges, though most of them can be mitigated, according to a 700-page environmental impact report prepared for the board.

   The EIR, which supervisors must also approve, noted multiple ``significant'' consequences arising from the wine country plan, including a reduction of farmland, increased noise, lower air quality from grading, excavation and other construction activity, as well as higher traffic volume and more roadway congestion. 

   In September, speakers critical of the proposal expressed concerns about noise, excess commercial growth and the consequent loss of a rural flavor to the community. 

   Supporters lauded the prospect of more tourism and other business gravitating to the area as the build-out occurs over the next several decades.