AUSTIN (KXAN) — A creek on the border of Travis and Hays counties that scientists have called one of the last “untouched” corners of the state has become the center of a debate between conservationists and developers.

A pristine waterway, Roy Creek Canyon, is home to 700-year-old cypress trees and numerous endangered species.

Last year, plans were announced for the construction of a new 1,400-acre “conservation-scale” development called Mirasol Springs on the surrounding ranch land.

For the past three months, KXAN has been taking an in-depth look into the history of the reserve, the development and the debate over the future of Roy Creek and the Roy Creek Canyon Reserve.

One of the last ‘untouched’ waterways in Texas

Hidden among rolling canyons and deep ravines, Lew Adams calls the Roy Creek Canyon Reserve “one of the best-kept secrets” in Central Texas. There are no public roads and no public access. Seeing the site firsthand is invite-only.

The canyon is located just a few miles west of Austin, near Hamilton Pool and Reimers Ranch. Roy Creek runs through the reserve, fed by naturally occurring springs, and then flows into the Pedernales River.

Adam’s father and a friend bought the canyon from the surrounding ranch in 1941 after stumbling on it during a hunting trip.

“They decided at that time, seal the deal with a handshake, that they would keep it in its pristine condition forever and never develop it,” Adams said.

The canyon has become a sacred site for students and scientists over the decades.

The University of Texas at Austin has hosted a field lab at the canyon for years and scientists with the Texas Parks and Wildlife Department and the San Antonio Zoo have conducted research with the canyon.

Adams shared video with KXAN of school trips to the canyon. One student in the video describes the canyon as “really beautiful… it’s like nowhere I’ve ever been before.”

Colin Morrison, a doctoral student at UT, has visited the canyon multiple times.

“This is one of the most pristine areas that I’ve seen in the Hill Country is a very, very good looking area,” Morrison said.

He discovered a rare species of passion vine during one of these trips.

“He walked down this trail, and he looked over, and within 15 minutes, he found the vine right here,” Adams said.

Morrison said he hasn’t seen invasive species in the Roy Creek Canyon Reserve, and because it’s virtually untouched, Morrison said, “It’s a really good place for researchers to go because we can see what that part of the Hill Country looked like before it became developed.”

Developers aim to conserve the land

Last April, Dallas billionaire and entrepreneur Stephen Winn announced plans for Mirasol Springs, a development including 50 homes, 30 cottages and a hotel, on the lands surrounding the Roy Creek Canyon Reserve.

One of those team members is the design firm, Hart Howerton. Its website says the firm specializes in design where “unique historic or natural environment requires an especially thoughtful and innovative solution.”

KXAN spoke with the Mirasol Capital team about the development and what exactly they meant by “conservation-scale.”

Jim Truitt, director of Mirasol Capital, said that they will “be guided by a land-use plan that defines and enforces sustainable design,” that homes on the property will have a limited footprint, that they will work “forever” to restore and protect the land, and they plan to preserve open spaces.

One of the key features of their plan is the new Hill Country Field Station that will be built in partnership with UT.

The current outdoor lab UT uses near Roy Creek Canyon Reserve will go away, while Mirasol Springs will construct a new facility that faculty and staff will be able use while staying on site. “(It) will serve as an anchor for the environmental stewardship that the property represents,” Truitt said.

Mirasol Capital said it has assembled a team of “designers, engineers, farmers, land developers, and environmental consultants to create a project that is focused on all of those things: stewardship, conservation, environmental enhancement and eco-sensitive design and development.”

KXAN checked with the Texas Department of Environmental Quality for any complaints filed against the firm, but were unable to find any.

We also checked for any complaints in states where they’ve worked in the past, including New York, California and Illinois. We were unable to find any complaints in those states.

The developers also sought out “environmental consultants” as part of their project. Brian Hunt, a hydrologist with UT consulted Mirasol Springs as part of their planning.

“I’ve had lots of interactions with, you know, developers and groundwater suppliers. And, and this was really unusual,” Hunt said.

“(Stephen Winn) was wanting to understand the system and what the challenges were. And so that’s the way they view it, I think they see these as challenges that can be overcome.”

Truitt told KXAN that they are still in the early stages of development, but preliminary plans are that homes built on the property will include multiple deed restrictions, such as the prohibition of pesticides and that homes must ensure “100% collection of rainfall on roofs.” Xeriscaping will also be required.

Traffic will also be limited on the property and a dark skies ordinance will be put in place. This will help reduce light pollution.

Two other key priorities for the development are water use and water quality. There’s a good reason for that. Both have direct impacts on Roy Creek Canyon and Lew Adam’s reserve.

Protecting the waters of Roy Creek

“The canyon is about 200 feet deep,” Adams said as he led a KXAN crew into the canyon back in January. We were invited out to see the canyon first hand and why Adams was so concerned about the development. Adams pointed at a section of the canyon’s limestone cliffs.

“It has the consistency of Swiss cheese,” he said.

The canyon was full of tiny holes called Karst. “When groundwater hits the top, it ends up filtering down. And we’re concerned about it, you know, ending up in the creek,” Adams said. “Any development that was within the watershed of Roy Creek, eventually goes into the Pedernales and eventually into Lake Travis.”

This is something the developers of Mirasol Springs know. When Brian Hunt spoke with them, he explained to them the pathways water take on the property.

Hunt was commissioned by Travis County to conduct a three-year study of the Hamilton Pool watershed. The southern part of that study includes Roy Creek. He gave Mirasol Capital a preliminary assessment of the property.

“(The) pathway of groundwater flow is complicated, it can go in and right back out, or it can go a little bit deeper, and all of it eventually is headed towards the low points. So that’s along Roy Creek,” Hunt said.

This means that any construction runoff, septic systems or wastewater could eventually find its way downstream. Hunt also said the springs that feed Roy Creek would be threatened if wells were built on the property.

“If they pump groundwater in the layers that are feeding those springs, clearly, there’s going to be an impact. So I communicated that to Mr. Winn.”

Based on this and others’ research presented to Mirasol Capital, Truitt told KXAN:

• Septic systems and private wells won’t be built on the property
• Rainfall will be harvested, reducing runoff
• Herbicides and pesticides will be banned
• Limited development footprints on home plots
• Curbs, gutters and storm drains will not flow into the creeks

“The goal of the project is to limit the use of (water) through water conservation including reclaimed water and harvested rainwater,” Truitt said.

Despite these plans, Hunt said the developers will likely have an impact on the creek.

“We all, myself included, every time we drive out there we have an impact, this project will have an impact. It’s just the nature of humans living on their surface,” Hunt said.

Protecting the land forever

In 1975, a documentary was released that would be shown in classrooms for decades called “What Good is a Warbler?” The film tracked the life cycle of the Golden Cheek Warbler. It was shot and produced in Roy Creek Canyon by two well-known Hill Country conservationists, Red and Marjorie Adams, Lew’s parents.

The film brought attention to the Golden Cheek Warbler, an endangered species that makes its home in Roy Creek.

This endangered bird and its history may be key in Lew’s goal of preventing the development of the Roy Creek Canyon Reserve by way of a conservation easement.

Frank Davis, the chief conservation officer with the Hill Country Conservancy, said that a conservation easement is a special type of land ownership.

“Rather than the right to impact the land, it’s the right to ensure that the land is not developed substantially beyond a certain point,” Davis said.

Here’s how it works:

Say you own land you don’t want to be developed and the land meets specific criteria, like serving as habitat to an endangered species, a group like the Hill Country Conservancy then can buy the conservation rights to your land.

“It’s going to remain with the land forever. So if they choose to sell the land, it’s going to be subject to that conservation easement in the future,” Davis said.

Adams is working with Hays County to get one place on the canyon, but he’s not the only one. Mirasol Capital is also working to have a separate conservation easement placed on Mirasol Springs, limiting further development of the area.

The future of Roy Creek Canyon

When it comes to conservation, there’s a lot of land that Mirasol Capital is trying to protect. That includes a 2.5-mile stretch of Roy Creek that is owned by Mirasol Capital. Roy Creek flows into the Pedernales River, and then into the Colorado River and finally into Lake Travis. That lake is one of the sources of Austin’s drinking water. While it isn’t the only source that connects to this water system, Truitt said his team takes stewardship of it seriously.

For Adams, the preliminary work undertaken by Mirasol Capital has been a good sign.

“There is a such a tremendous opportunity here for education and the future scientific world to use this as a laboratory, a living laboratory of how to restore and bring our hill country back to its natural state,” Adams said.

Adams said he has spoken with Mirasol Capital multiple times about the preservation of Roy Creek Canyon, but he says multiple meetings have been rescheduled.

“They may never see eye to eye and the truth is somewhere in the middle,” Hunt said.

Adams is still optimistic.

“We think it’s important that we, we work with the landowners in some way that brings about a positive result,” he said.

Mirasol Springs is still in the preliminary stages of planning. Site development plans will likely be developed in the coming months. It’s hoping to break ground in 2023.