Why the Canyon Ranch Permit Cannot Be Evaluated in Isolation

TCEQ evaluates wastewater permits one at a time, as if each outfall exists in a vacuum. But Canyon Lake does not receive wastewater from a single source. It receives multiple discharges, from multiple facilities, across multiple counties, including upstream effluent flowing down the Guadalupe River.

When viewed as a watershed — not an isolated permit — the cumulative impact is substantial.

1. Pending & active permits to discharge effluent locally into Canyon Lake stand at 1,441,000 gallons/day

Five wastewater facilities discharge into Canyon Lake or its tributaries. Permitted volumes:

• Canyon Park Estates (GBRA) – 260,000 GPD

• JBSA Jacobs Creek (US Air Force) – 21,000 GPD

• Canyon Ranch (Utilities, Inc.) – 300,000 GPD (renewal pending)

• Simmons Valley (Lennar) – 260,000 GPD

• Broken Cedar Ranch (Lennar, pending) – 600,000 GPD

Total potential discharge: 1.441 MGD  

This is the cumulative load before accounting for upstream effluent. TCEQ does not evaluate these permits together.

It evaluates each one separately — even though they discharge into the same drinking‑water reservoir.

2. Broken Cedar Ranch Is a Massive Escalation - 600,000 GPD — larger than Canyon Ranch + Simmons Valley combined

Broken Cedar Ranch alone represents:

• • 44% of total wastewater volume

  • almost half of total nutrient loading across all facilities

  • the largest single discharge ever proposed for the Canyon Lake watershed

This one permit dramatically increases cumulative nutrient loading — especially phosphorus, ammonia, and CBOD5 — all of which drive biological change in warm, shallow water.

3. Upstream Effluent Adds More Than 5 MGD

Kerrville, Comfort, and other upstream plants discharge into the Guadalupe River

Upstream facilities collectively are permitted to discharge over 5 million gallons per day into the Guadalupe River. This water flows:

• through Kerr County

• through Kendall County

• through Comal County

• directly into Canyon Lake

This upstream loading is not included in Canyon Ranch’s permit analysis.

When combined with local discharges, permits for discharge into Canyon Lake are nearly 6.5 MGD of effluent  from upstream + local sources.

This is the true cumulative impact — and it is not evaluated under current rules.

4. Drinking‑Water Impacts Extend Across the Region

Canyon Lake is a drinking‑water source for multiple counties

Canyon Lake supplies drinking water to:

• Comal County

• Bexar County

• Kendall County

• Hays County

• Guadalupe County

• and portions of additional counties through GBRA retail and wholesale systems

Depending on the distribution system, as many as 11 counties may be affected by nutrient loading and biological changes in Canyon Lake.

This is not a neighborhood issue — it is a regional drinking‑water issue.

6. Flow Path Through the Trinity Aquifer Recharge Zone Amplifies Impact

More effluent = more infiltration

Nearly two miles of the Devils Hollow flow path lie within the Trinity Aquifer recharge zone, where the Cow Creek Formation is exposed.

As cumulative wastewater volumes increase:

• infiltration increases

• nutrient loading increases

• biological hazards increase

• groundwater vulnerability increases

Cumulative impact is not just a surface‑water issue — it is a groundwater‑pathway issue.

6. Flow Path Through the Trinity Aquifer Recharge Zone Amplifies Impact

More effluent = more infiltration

Nearly two miles of the Devils Hollow flow path lie within the Trinity Aquifer recharge zone, where the Cow Creek Formation is exposed.

As cumulative wastewater volumes increase:

• infiltration increases

• nutrient loading increases

• biological hazards increase

• groundwater vulnerability increases

Cumulative impact is not just a surface‑water issue — it is a groundwater‑pathway issue.

7. Why This Matters for Policy and Rulemaking

This permit illustrates the gap Senator Campbell and Rep. Isaac identified

Both legislators have already asked TCEQ to:

• • evaluate cumulative impacts

  • strengthen antidegradation protections

  • adopt watershed‑specific standards

  • modernize TLAP rules

  • address nutrient loading in drinking‑water reservoirs

The Canyon Ranch permit — combined with Broken Cedar Ranch, Simmons Valley, and upstream dischargers — is a textbook example of why cumulative‑impact modeling is urgently needed.

The Takeaway

The Canyon Ranch permit does not account for:

• four other existing/pending Canyon Lake wastewater facilities

• 5 MGD of permitted upstream effluent

• foreseeable future tie‑ins due tothousands of undeveloped acres within three miles of Canyon Ranch, Simmons Valley, and Broken Cedar

• regional drinking‑water dependence

• groundwater vulnerability in the recharge zone

Evaluating Canyon Ranch in isolation is not scientifically defensible and not aligned with legislative priorities.

Cumulative impact is essential.

Future development must be part of the analysis.

The watershed must be evaluated as a whole.