There's a new cash crop sprouting in the Wasatch County bottomlands - "For Sale" signs. Developers are eating up farms and spitting out houses. Unless county and municipal officials apply the brakes, the Heber Valley could suffer the rapid development that has eroded Summit and Weber counties, and runaway growth could threaten not just the quality of life, but a way of life.

It's already happening. Wasatch County's population grew by a third in less than eight years, from just over 15,000 in 2000 to more than 20,000 today.

And the seeds for more growth are planted. Projects for a combined 10,000 new dwelling units have been approved by county planners, and proposals for another 5,000 new homes are germinating. While approximately two-thirds of the proposed homes in the pipeline border the Jordanelle Reservoir, the building boom is spreading into the valley, and real estate signs in alfalfa fields are a sad part of the stunning scenery.

Growth might be inevitable, but it need not be regrettable, some county and municipal officials say. If they can strike a balance between development and preservation, walk the fine line between sustainable growth and sprawl, perhaps they can have it all.

Many of the tools needed for smart growth are already in place. Hefty development fees. Conservation easements. An open-space board that encourages farmland preservation. Zoning that requires up to 40 percent of land to be preserved as green space.

But there's a tool missing from the box. You can't save a valley without an open-space preservation bond any more than you can change a tire without a lug wrench. With money in hand, the county could buy prime tracts for the public before they fall prey to developers.

The slowing economy and the mortgage crisis have temporarily slowed the mad march toward build-out, and given county officials a chance to catch their breath. They should take this opportunity to gather their wits, fine-tune their ordinances, establish priorities.

And they should place an open-space preservation bond proposal on the ballot, and consider a moratorium on new construction until the votes are counted. Residents should be given a chance to decide their future: Pay a little now, or pay dearly for their failure to act in years to come.