To preserve open space and promote agricultural operations, the California Land Conservation Act of 1965, better known as the Williamson Act, enables local governments to enter into contracts with private landowners who agree to meet specific income and use requirements for their property in exchange for substantial tax reductions. Nearly 17 million acres are protected statewide under this law. In Sonoma County, for example, rules require minimum gross annual income of $200 per acre for prime (Type I) farmland, $2.50 to $199.99 per acre for non-prime (Type II) farmland, and $2,000 per farm operation. Minimum parcel size is 10 acres for Type I farmland and 40 acres for Type II. In 2004, California enacted Government Code Section 51250 (AB 1492), an enforcement law that establishes penalties for material breaches of a Williamson Act contract. A common example of a material breach would be having a commercial, industrial, or residential building exceeding 2,500 square feet when the property is out of compliance with contract terms. The new law imposes a monetary penalty of 25 percent of the unrestricted fair market value of the land rendered incompatible by the breach, plus 25 percent of the value of the incompatible buildings and any related improvements on the contracted land. These penalties present significant financial risks to property owners. Under the new compliance process, county assessors will send out questionnaires and follow up on obtaining required information. They will refer properties with unverified agricultural use or suspected violations to the Permit and Resource Management Department for review and action. The stricter enforcement is the result of a 2005 state audit that questioned land uses that the county had historically deemed compliant. Those uses include public spaces; churches and schools; visitor serving areas such as restaurants, event centers, and tasting rooms; horse breeding, boarding, and training facilities; lumber and logging mills and mill ponds; private air strips; commercial raising of fur-bearing animals; and recreational facilities, including fish ponds and guest houses. In January 2007, the county approved interim rules for the uses under review. Four areas of special interest to general property owners are facing tighter restrictions: visitor serving areas, horse facilities, guest houses, and residential density. While saving on your property taxes sounds appealing, signing a Williamson Act contract commits you to an open-ended agreement that allows state and county agencies to freely change the rules you must follow to remain compliant. The only say you have about those rules is through your elected officials. It is becoming increasingly clear that the state no longer wants to subsidize local property taxes and is restricting property rights to make Williamson Act contracts less attractive. Even if you opt to terminate the contract, you are locked in for 10 years after you make the decision, which is generally longer than landowners want to wait. Further changes and tighter restrictions appear likely for Williamson Act properties, ones that contract-free properties will not have to bear. Depending on how you plan to use your land, a Williamson Act contract may be more confining and financially risky than the tax savings are worth.