Mark Twain’s observation, “Whisky is for drinking, water is for fighting,” arose from his experiences in the arid West. Some claim that more westerners have been killed with irrigation shovels than with guns. An old neighbor told me that a man was killed on our place during the drought of the 1930s. In Montana -- and wherever water’s scarce -- conflict looms.

Montana water law follows the doctrine of prior appropriation: first in time, first in right. In dry years, junior rights must yield to older ones.

Originally, prior appropriation focused primarily on mining and agriculture; it assumed that not everyone would use all their water all the time. A farmer would never irrigate unceasingly, for his crops would waterlog and die. Due to this fact, our current water rights system has overallocated a finite resource.

Both visible and tangible, surface water is relatively easy. If you utilize rights to certain surface water and someone takes it from you, you’ll immediately note its absence. These property rights are clearly defined and easily monitored.

However, as western Montana becomes more heavily populated, conflicts shift to groundwater. Here are three of our region’s ongoing economic, cultural, and demographic transformations. All have powerful implications for western water issues.

First, the cost of distance has precipitously declined over the last 40 years. Vehicles are faster, safer, and more comfortable. We can fly to any major U.S. city in a few hours. High-speed Internet access is widely available and cheap. FedEx and UPS deliver overnight. Regardless of the season, we have fresh produce in Bozeman.

Second, our region has become a haven and magnet for funhogs. These same people are disenchanted with urban life. And, resources permitting, those still not ready to give up on city life are happy to build second or third homes here. Demand increases; land becomes ever more valuable.

Third, ag commodities are decreasing in price. Improved economic coordination demands that we compete with the world’s most efficient producers. And we can’t. Lower incomes and higher costs coax many farmers to sell to developers. Land purchased for $300 an acre 30 years ago now fetches $30,000 an acre.

Here’s the problem: since new homeowners can no longer appropriate surface water, they must rely on groundwater (unless they are within city limits). The conflict moves underground.

Groundwater is tricky. Invisible, this resource is part of a complex system. The science of hydrogeology involves substantial guesswork. The interactions between groundwater and surface water are poorly understood. And it is expensive to study or monitor groundwater.

Therefore, it is extremely difficult to establish strong property rights for groundwater appropriations. This makes it easier for money and power to dominate the conflicts.

A stark example can be found in Nevada; it makes Montana’s problems seem minor irritants. The fastest-growing state, Nevada’s 1980 population of 800,000 is projected to balloon to 4 million by 2030. And while the city of Las Vegas has only enough water to support its population until 2013, it has more than enough money to buy it.

Las Vegas is fighting two battles, one seeking more Colorado River water, the other coveting a deep aquifer in northeastern Nevada. Hydrogeologists are concerned that tapping this aquifer may deprive much of rural Nevada of its water supply.

Rural Nevadans are afraid they will lose this water fight. They understand that the Southern Nevada Water Authority, in charge of Las Vegas’ water, has an annual budget of over $640 million. In contrast, White Pine County, situated above the contested aquifer, is broke.

The Montana Water Act of 1973 upheld over 100 years of surface water precedent. But groundwater issues lack a commensurate history of strong property rights. This makes groundwater more vulnerable to financial and political pressures. Las Vegas may offer a preview of fights to come here.

Here’s a generalization that applies across time and cultures: water moves uphill toward money. Without updated institutions to check this movement in the interests of equity, ecology, or tradition, water pressure will dissolve whatever stands in its way.