The amount of revenue that can be generated from Napa Appellation wines will be a relatively fixed amount - depending on the slow development of new vineyards, of marketing strategies that may raise the price per bottle and of inflation. Tourism revenue however can continue to climb as new tourist attractions are conceived (hotel wineries, b&b wineries, casino wineries, amusement park wineries - the winery aspects a mere pretext to get the projects approved) and new facilities are constructed. The tourism industry, if left unregulated, will eventually swamp the wine industry and land use decisions will be based more and more on what is good for the tourism industry and not what is good for the wine industry. The vineyards will be eaten up for event parking lots, resorts, city expansion etc.
Given the impacts that tourism is already having on the county, vis-a-vis traffic, water and land consumption, it is a good time to look at those numbers and recognize that tourism, at about 1/4 the total economy of the ag zone, might be a level that should be maintained through zoning policies. That ratio could be increased, by development in the municipalities, but only if the protections of the agricultural land become even stricter than they are now, to insure that the increasing pressure created by ever denser tourism developments in town and the changing demographics created by an ever increasing tourism work force do not threaten the agricultural lands. The percentage of votes needed to rezone agricultural land, which is a simple majority under the 1990 measure J , may need to be adjusted.
Another possibility might be to have a fixed total number of winery tourist slots per year in the county, creating a market in tourism slots. A winery wishing to have more tourists would have to buy them from someone else.