Hays Commons

An uncommonly bad development

If you wanted to build a big subdivision in a really bad place, where would you put it?  Would you build it where surface water can seep directly into the Edwards Aquifer, a source of drinking water for hundreds of nearby wells? And would you build it in the watershed of one of the last pristine streams in Texas? Unfortunately, this is exactly what Milestone Community Builders wants to do. The Austin-based company plans to construct its Hays Commons subdivision in one of the worst places possible — over the Edwards Aquifer Recharge Zone, and in the Onion Creek watershed. Milestone has proposed building more than 700 houses in its subdivision, which would be located northwest of Buda at the intersection of SH 45 and FM 1626.

Unlike most aquifers in Texas that hold water in underground layers of wet sand or gravel, the Edwards is unique because it stores water in karst, a type of limestone (see the photo at the top of this page for an example). Karst is often compared to Swiss cheese because it’s riddled with countless cracks and holes, ranging in size from tiny veins to large caves. In the Recharge Zone, surface water seeps through fissures and openings in the ground and down into the Edwards, where it then flows through the empty spaces in the karst rock. An aquifer located in karst doesn’t filter out pollutants. If the water that seeps into the Edwards Aquifer contains pollutants, those pollutants will still be in the water that’s pumped out by nearby residential wells. 

First map: Hays Commons would be located over the Edwards Aquifer Recharge Zone. In the aquifer, water flows underground in the direction of the blue arrows towards Barton Springs. Second map: The City of Austin has purchased hundreds of acres for its Water Quality Protection Lands program. Development is permanently prohibited in WQPL properties to keep the water in the Edwards Aquifer as clean as possible.

Hays Commons: wastewater pollution

The Texas Commission on Environmental Quality (TCEQ) has already issued a draft wastewater permit for the Hays Commons subdivision. This permit, officially known as a Texas Land Application Permit (TLAP), would allow Hays Commons to irrigate its treated wastewater (aka sewage) onto land. Getting rid of treated wastewater this way is usually a better option than discharging it into streams, but irrigation isn’t without its own problems. Irrigation systems can turn into discharge systems if wastewater is applied onto saturated fields, which causes runoff. Nearby wastewater irrigation systems in the Belterra, Barton Creek West, and West Cypress Hills subdivisions have had incidents of wastewater runoff, and TCEQ fined Dripping Springs in 2017 for allowing treated wastewater to run off into Onion Creek.

Irrigation fields can become saturated when they’re still wet from heavy rains, but this can also happen because of maintenance and monitoring failures. Because wastewater irrigation systems are assumed to be less problematic than wastewater discharge systems, they may not be monitored and maintained as rigorously. While wastewater discharge systems are required to regularly report their own monitoring data to TCEQ, wastewater irrigation systems are not, making it impossible for the public to know how reliable they are. The Hays Common irrigation fields would be located around several sensitive karst features in the Recharge Zone. Because there are currently no active wastewater irrigation permits that are located in the Recharge Zone itself, TCEQ has no actual knowledge about whether permits of this kind could pollute drinking water in the Edwards Aquifer.

First photo: Water seeps into the Edwards Aquifer through surface fissures and openings in the karst limestone such as this one. Many of these “recharge features,” as they're called, have been discovered throughout the Hays Commons property. Second photo: Runoff from the new impervious cover built in Hays Commons would also flow into Little Bear Creek, which drains into Onion Creek.

Hays Commons: stormwater pollution

When rain falls onto ground that’s still in its natural and undeveloped state, most of the water will soak into the soil where it falls. Roofs, roads, parking lots, and sidewalks are called “impervious cover” because water can’t soak through these surfaces. Instead, rainwater will flow away as runoff, and it will carry away any substances that have accumulated on these surfaces between storms, including chemicals, trash, and waste. This runoff can be very dirty. According to some studies, the first inch of rain that falls on roofs and roads can be as polluted as raw untreated sewage. Adding new impervious cover to an undeveloped property — which Hays Commons would do — will increase the amount of runoff for the property. Dirty runoff from the subdivision would seep directly into the Edwards Aquifer Recharge Zone and contaminate its water..

Hays Commons also would straddle Little Bear Creek, a tributary of Onion Creek. TCEQ has recognized Onion Creek as one of the last remaining pristine streams in Texas. This means that it has exceptionally low levels of naturally occurring pollutants. If Hays Commons is built, it will create more rain runoff that will increase the risks of pollution and flooding for downstream residents on Onion Creek.

A 2008 geological survey identified many recharge features, indicated by the yellow and purple dots on this map,  in the southern portion of the Hays Commons tract.

Hays Commons: Development options

Milestone’s key dilemma has been how to get water and wastewater service for its high-density subdivision. The company has been pursuing two pathways that we’ve called the “A La Carte Option” and the “Buffet Option’ (see our chart below). Under the Buffet Option, Milestone would get all of the development approvals that it needs from a single source — Austin. City officials would need to approve Milestone’s pending application to create a Municipal Utility District (MUD), which would also include a Service Extension Request (SER) to extend Austin's water and wastewater lines to Hays Commons. The city has already rejected a request from the developer to build a larger amount of impervious cover over the Recharge Zone than would be allowed under Austin’s Save Our Springs Ordinance.

Under the A La Carte Option, Milestone would get the approvals that it needs for Hays Commons from several different sources. MUDs can also be created by the Texas Commission on Environmental Quality, and TCEQ has already approved one for Hays Commons, though local landowners are currently challenging that decision in Travis County District Court with legal assistance from SOS Alliance. The development plan for the southern half of Hays Commons, which is in an unincorporated area of Hays County, would have to be approved by that county's officials. They’ve already rejected development plans for Hays Commons twice, with the commissioners’ vote last month being the most recent denial. (You can read more in this KXAN story.) The development plan for the northern part of Milestone’s subdivision, which is in Austin's Extra-Territorial Jurisdiction (ETJ) area, would have to be approved by that city's officials.

 For wastewater service under the A La Carte Option, Milestone would build an onsite wastewater treatment facility at Hays Commons. The company has applied to TCEQ for a Texas Land Application Permit (TLAP) that would allow it to irrigate Hays Commons’ treated sewage onto the ground — and over the Edwards Aquifer Recharge Zone. TCEQ issued a draft permit for the TLAP application last year, but local landowners requested a contested case hearing on it, which will be held by the State Office of Administrative Hearings (SOAH) in November.

The biggest unknown in the A La Carte Option is whether Milestone would be able to pump enough underground water from onsite wells to supply the hundreds of houses that it wants to build. The previous owner of the southern half of the Hays Commons property received permits from the Barton Springs Edwards Aquifer Conservation District to drill four wells on the property. Milestone is conducting tests on one of these wells; after that, the company can submit applications to BSEACD for pumping permits. Despite recent rains, the district still remains in a Stage 3 drought condition, the next-to-worst level.

Several development projects for the Hays Commons area have been proposed over the years. In 1986, Austin officials opposed an application for a wastewater permit for a proposed development that would have been located in the city’s ETJ area and just north of the Hays Commons tract. The officials based the city’s opposition on the grounds that this development would have encouraged sprawl. In 2017, the previous owner for the southern half of the Hays Commons property asked Austin to extend its water and wastewater lines to the property, but the city refused, saying that the extension “would facilitate increased development intensity in an environmentally sensitive area.”