In Costilla County, a well sits inside the San Luis Valley's water rules

The San Luis Valley looks dry on top, but it sits over large groundwater aquifers. Because so many people draw from those aquifers, the state manages valley wells more closely than wells in many other parts of Colorado.

In recent years, many valley well users, especially farms and others pumping larger amounts, have had to cover the water their pumping takes from the aquifer, called replacing depletions, or join a local group that does this for its members. Small household-only wells are often handled differently: their limits are usually written into the permit itself. What a given well owes depends on its permit, the aquifer it taps, its allowed uses, and the basin’s rules. So “the property has a well” does not by itself answer how much water you can use, for what, or what ongoing obligations come with it.

There is also more than one kind of aquifer here. Water near the surface and water trapped under clay layers deeper down are treated differently, and a permit spells out which one a well taps and the uses it allows, such as household-only versus irrigation.

None of this is a reason to avoid valley land. It is a reason to read the well permit and ask questions early. Before relying on a well in Costilla County, check the permit and the local groundwater rules with the state water agency for this basin, the Division of Water Resources Division 3 office.