SAN LUIS • A Texas businessman who built an 8.5-foot-high fence partially around his ranch in Colorado’s San Luis Valley could face fines of up to $65,544 per day after state regulators determined runoff from the disturbed land could contaminate area water supplies.

The Cielo Vista Ranch, which traces its origins to a Spanish land grant, spans 83,000 acres of rolling hills, forests and steep mountains near the town of San Luis. It was bought in 2017 by William Harrison, heir to a Texas oil fortune.

It’s a tract of land that 5,000 residents, descendants of Hispanic settlers, have been allowed to use for generations for grazing, firewood and as the headwaters of their water supplies — rights that were affirmed in the 40-year court case.

In 2020, Harrison began constructing the fence. Residents said it limited their access and claimed it caused disruptions in the movement of wildlife and sediment to wash into their streams.

The latter issue led the Colorado Department of Public Health and Environment last year to require the ranch to obtain a stormwater runoff plan. The cease-and-desist order sent Nov. 12 alleged that “no control measures were implemented to manage areas of disturbance in multiple project locations. As a result of these deficiencies, there was an increased potential for sediment and polluted stormwater to discharge offsite.”

The fence and the roads bulldozed to build it run up and down steep drainages known as arroyos, and the state required measures like restoring vegetation and installing erosion blankets and hay bales to hold the soil in place when it rains and the snow melts off the 14,000-foot peaks above.

The order gave the ranch 30 days to present a plan “to take all necessary steps to minimize or prevent the discharge of pollutants from the permitted area and manage any stormwater runoff onto the site until a control measure is implemented and made operational and/or an inadequate control measure is replaced or corrected and returned to effective operating condition.”

“We’re thankful (for the enforcement action) for our community, to protect our watershed and our water and have an advocate for our community to make them accountable for the damage they have done,” said Bernadette Lucero, one of the residents who has been fighting the fence.

Costilla County in 2022 cited the ranch for land-use violations and the next year put a moratorium on all fences over 5 feet high. The landowner sued the county. Residents said the owner ignored the moratorium by continuing to put up the fence.

By the time the courts intervened, more than 20 miles of fence had been built, in some cases walling in residents on three sides.

Gov. Jared Polis had visited the area to sign a bill giving local authorities the ability to regulate fences over 5 feet tall, aimed specifically at the Cielo Vista Ranch.

Messages left with Harrison’s attorney and the ranch were not returned Thursday. He said previously that the fence was built to keep out trespassers and keep in his small herd of bison.

Residents said the fence, built with few wildlife jumps, has kept elk and deer from moving around and that it goes all the way to the ground to restrict the movement of even small animals.

The county and ranch are currently finalizing a wildlife study to assess the impacts and offer solutions.