The price for a share of northern Colorado’s largest water-supply project has nearly doubled this year, and such upswings in prices create a tough situation for anyone in the agriculture industry in need of more water.

In January, a unit of the Colorado-Big Thompson Project was selling for $9,500. Last month, units sold for as much as $18,500, according to officials at the Northern Colorado Water Conservancy District, which oversees the C-BT Project’s 12-reservoir system.

Brian Werner, a spokesman and historian who’s been with Northern Water for more than 30 years, said the recent price marks an all-time high for C-BT Project shares.

Regional water experts say the skyrocketing water prices are partly attributed to recent profitability in agriculture and farmers’ increased reluctance to sell their water rights.

Seeing fewer farmers sell their water is good news for northern Colorado’s robust agriculture industry, which has watched its ownership of water decline over the years.

The minimal amount of water on the market is pushing already high prices to a point where farmers could have even more trouble affording water if they’re looking for it.

“It’s certainly not farmers who are paying these high prices right now,” Werner said.

For years, farmers have sold their water to growing cities in the region, either because they were retiring from farming and didn’t have children taking over operations, or because they were pursuing other careers, since farming wasn’t profitable at the time.

That’s not the case anymore.

Increased demand for corn and other agricultural goods — stemming from droughts and upswings in biofuel production and food demand abroad — has led to higher commodity prices, and recently to some of the best income years in decades for many farmers and ranchers.

Producers still in the agriculture game want to stay in it, and they’re hanging on tighter to their water.

Local water officials say growing cities in Colorado are still buying water, but there’s much less of it to buy.

“Cities have already picked the low-hanging fruit,” said Randy Ray, executive director of the Central Colorado Water Conservancy District in Greeley.