Edwards Aquifer and karst consulting for Central Texas land development.
TerraPoint provides pre-acquisition karst constraints screens, TCEQ Geologic Assessments, USFWS-permitted karst invertebrate surveys, municipal reviews for Austin and San Antonio, and construction-phase karst support. Every step is overseen directly by a senior geoscientist, from the first site walk to final approval.
The geology is on the critical path
Regulated projects on the Edwards Aquifer Recharge and Transition Zones move only after TCEQ approves an application built on a Geologic Assessment. Until the geology is done, everything behind it waits.
TerraPoint holds a USFWS permit covering 19 federally listed endangered species. When a project needs karst invertebrate habitat evaluation or presence/absence surveys, the work stays in-house, under permit.
The Edwards Aquifer Protection Program spans eight counties across one of the fastest-growing development corridors in the country. Teams that move through the program cleanly are the ones that keep their schedules.
Direct senior oversight from first site walk to final sign-off
Each step feeds the next. The screen informs the acquisition, the features mapped in the assessment shape the site plan and anchor the permit application, and the same site knowledge drives the response when construction reaches the ground. No handoffs between firms, no context lost between phases.
Karst Constraints Screen
Before the land closes, a desktop analysis of the karst questions that decide whether a site is worth pursuing: which Edwards Aquifer zone it sits in, whether known karst features or indications of karst are present, which USFWS karst zone applies, and what the endangered species compliance path looks like. Where features are known, an anticipated buffer analysis maps the required buffers against the site, so you can see early whether they would constrain the development, or preclude it. We have seen them do both.
- Edwards Aquifer zone and regulatory jurisdiction determination: TCEQ, City of Austin, SAWS
- USFWS karst zone determination and screen for federally listed salamanders, with the compliance path outlined for each: habitat assessment, survey, coordination, or habitat conservation plan participation where available and appropriate
- Anticipated buffer analysis where karst features are known, mapped against the developable area
Site Assessment
The Geologic Assessment is the document every Recharge and Transition Zone application stands on: karst features located and evaluated one by one, units mapped from observation rather than compiled from the published sheet, sensitivity scored on the TCEQ assessment table. Where federally listed karst invertebrates are in play, habitat evaluations and presence/absence surveys run alongside it, together with the municipal reviews Austin and San Antonio require.
TerraPoint is one of very few firms that can perform the Geologic Assessment, the Environmental Resource Inventory, and, under our own USFWS permit, the karst invertebrate habitat evaluations and presence/absence surveys. Combining them into one field effort means rapid turnaround, one contract instead of three, and pricing that reflects a single mobilization.
- Senior boots on the ground: every field survey is led by a licensed Professional Geoscientist with deep karst experience
- City of Austin Environmental Resource Inventories and SAWS Aquifer Protection Plans, where municipal requirements stack on top of TCEQ's
- Findings communicated to the project engineer early, while the site plan can still respond to them
WPAP and Application Support
The assessment doesn't sit in an appendix; it anchors the Water Pollution Abatement Plan your engineer submits. We stay on the team through approval, not just through delivery.
- Assessment packaged for direct incorporation into the WPAP, coordinated with the project engineer
- Feature buffers and geologic conditions addressed in the plan the way TCEQ reviewers expect to see them
- Comment-response support until the approval letter arrives
Encountered Feature Evaluation and Mitigation
Excavation over karst finds things. When your project encounters a cave or other unexpected feature, work in that area stops until a geologist has evaluated it, and every day of evaluation is a day of schedule. We evaluate encountered features in the field, document them for the project record, and prepare the mitigation plans TCEQ requires. How encountered feature mitigation works.
Encountered feature evaluation and mitigation
Karst doesn't respect construction schedules. The difference between a feature that costs days and a feature that costs a month is how quickly it is evaluated, documented, and resolved with the regulator.
Evaluation in the Field
A licensed geoscientist evaluates the encountered feature in the field: geometry, infill, fracture control, and evidence of recharge function. We work directly with your contractor, including the excavation needed to expose and characterize the feature, and give the project team a clear read on what it means for the work around it.
The Mitigation Package
Where TCEQ requires a mitigation plan, we prepare the complete submittal: feature documentation, assessment table scoring, the mitigation approach, and the construction schematic. The plan is developed in coordination with your project engineer and built around your contractor's means and methods, so what the regulator approves is what the field can build.
Continuity Is the Speed
The geologist who wrote your assessment is the one who evaluates your encountered features. No new firm learning the site, no mobilization of someone else's junior staff. That continuity is what turns a stopped excavator back on.
Most of the cost of an encountered feature isn't the mitigation. It's the waiting. This program exists to remove the waiting.
Avoid and minimize beats mitigate
The best karst strategy is set early in design. How early the geology reaches the design team determines how much of it the project has to carry.
Mitigation has its place, and we prepare mitigation plans regularly. But both TCEQ and the City of Austin require sensitive features to be avoided and buffered first, and those buffers become conditions of the approval either way. What early identification changes is when the features enter the design: buffers drawn into the site plan from the start, rather than forced into a finished layout during review.
That's why our assessments are built to inform the design, not just satisfy the checklist. That approach, worked out alongside project engineers and land planners, has meant:
- Completing the field survey early in the design process, so mapped features shape the site plan rather than disrupt it
- Establishing feature buffers and setbacks while the layout can still accommodate them
- Scoping mitigation narrowly when it is genuinely required, so the plan answers the regulator's question without inviting new ones
A feature identified early is a design consideration. The same feature identified late is a redesign.
How this plays out on real sites
Vignettes from practice, anonymized, from three different points in the sequence.
The cost of asking the geology question late
Some sites over the Edwards Aquifer carry too many karst features to support the development that makes the deal work. We have seen it under TCEQ review and under the City of Austin ERI: known caves and sinkholes whose required buffers left too little developable area for the project to pencil.
We have been brought in early, when a few hours of fieldwork answered that question before serious money followed it. We have also been brought in after the site plan was largely drawn, on a site where nobody had realized a Geologic Assessment was required, and the buffers around numerous known features precluded the development outright. The finding was the same either way. The difference was everything the client had already spent to learn it.
A cave in the wastewater trench
Trenching for a wastewater line on the Edwards Recharge Zone opened a cave. Under the Edwards rules, work around the feature stops until a geologist evaluates it and TCEQ approves a path forward. A TerraPoint geologist was on site the next morning, evaluated the feature, and submitted the encountered feature mitigation plan to TCEQ that same day. Approval to proceed with the mitigation and the wastewater line came within days.
Knowing the rules kept the stoppage contained. The contractor held only the exclusion zone TCEQ requires and leapfrogged crews to another section of the line while the plan was under review. We worked with the crew to install the temporary BMPs TCEQ requires to protect the feature, correctly the first time; improperly installed BMPs have triggered enforcement actions on other projects. When TCEQ visited the feature to inspect, we were there, and the inspection went smoothly: a workable mitigation for the client, full protection of the aquifer, and full compliance with the Edwards rules.
Two questions, one coordinated field effort
A large site in Williamson County, being redeveloped from mostly old ranchland, needed due diligence covering the geology and the endangered species questions together: a Geologic Assessment under the Edwards Aquifer rules, karst invertebrate habitat assessments and presence/absence surveys, and screening for potential Eurycea salamander habitat.
The work ran as one coordinated field effort. More than a dozen karst features were evaluated, over half of them newly discovered during our surveys, features no desktop review would have found. The features meeting USFWS criteria for potential karst invertebrate habitat received presence/absence surveys under Section 10(a)(1)(A) permit requirements; no listed species were detected. No springs and no potential salamander habitat were found on the property. The Geologic Assessment conformed to TCEQ's Instructions to Geologists under 30 TAC 213.
Karst geology is the core of the practice
TerraPoint was built on Edwards Aquifer karst geology. Geologic assessments, feature evaluations, and karst invertebrate surveys are the center of the firm's work, delivered with a production system that keeps them moving.
Licensed P.G., nearly two decades in practice
Every assessment, evaluation, and mitigation plan carries a licensed Professional Geoscientist's seal, with nearly two decades of karst, due diligence, and regulatory experience behind it. The person who signs the report is the person who walked your site.
Species surveys under our own USFWS permit
TerraPoint holds a USFWS permit covering 19 federally listed endangered species. The karst invertebrate work stays in-house, scoped by the same geologist reading the features, instead of routing through a second firm.
We speak TCEQ, USFWS, COA, and SAWS
Geologic assessments, WPAPs, City of Austin ERIs, SAWS Aquifer Protection Plans, USFWS karst invertebrate surveys and coordination, encountered feature mitigation plans: we work in these programs constantly, know what reviewers look for, and build submittals to be approved the first time.
A seat on the national karst standards committee
TerraPoint is represented on ASTM Subcommittee D18.27 on Karst, which develops the national standards for karst terrain assessment, including D8512 for preliminary karst assessment at development sites. The same practice that applies these standards in the field helps shape them.
Automation where it belongs
A structured field-capture and report-production pipeline handles the repeatable work, which is why senior-led work does not have to be slow work. The professional opinion is never automated. The paperwork around it is.
Frequently asked questions
Do I need a Geologic Assessment for my project?
A Geologic Assessment (form TCEQ-0585) is required for the applications that govern regulated activities on the Edwards Aquifer Recharge and Transition Zones: Water Pollution Abatement Plans on the Recharge Zone, and sewage collection system and storage tank facility plans in both zones. Projects on the Contributing Zone submit a Contributing Zone Plan instead, which does not require a Geologic Assessment. TCEQ requires the assessment to be prepared and certified by a licensed Professional Geoscientist.
What does a TCEQ Geologic Assessment include?
A field survey of the site by a geologist, identification and evaluation of karst and other sensitive features, geologic mapping of the units present, a stratigraphic column, and sensitivity scoring on the TCEQ assessment table. The completed assessment is certified by the geologist and submitted as part of the TCEQ application.
How long is a Geologic Assessment valid?
A Geologic Assessment included in a TCEQ application expires ten years after its original certification date, under TCEQ policy effective November 1, 2018. If site conditions change materially before then, the assessment should be revisited sooner.
Who can perform endangered karst invertebrate surveys?
Only holders of a USFWS Section 10(a)(1)(A) scientific permit can conduct presence/absence surveys for the federally listed karst invertebrates of Central Texas. TerraPoint holds a USFWS permit covering 19 federally listed endangered species, so habitat evaluations and surveys can run in the same field effort as the Geologic Assessment.
What are USFWS karst zones?
Mapped zones in Travis, Williamson, and Bexar Counties that rank the likelihood of habitat for federally listed karst invertebrates, from Zone 1 (areas known to contain listed species) outward. The zone a site falls in shapes the compliance path: habitat assessment, presence/absence surveys, coordination, or habitat conservation plan participation where available and appropriate.
What happens if construction encounters a cave or void?
Work in the area of the feature stops until a geologist evaluates it. The feature is documented and, where TCEQ requires it, an encountered feature mitigation plan is prepared and submitted before work in that area resumes. The speed of that evaluation and submittal is usually what decides how much schedule the feature costs.
Can karst features prevent a site from being developed?
They can. Sensitive features carry required buffers that become conditions of the approval, and on some sites the buffers consume enough of the developable area to make the project infeasible. That is the question a pre-acquisition karst constraints screen answers before the land closes.
Send us your site.
Share the parcel and where the project stands. We'll scope the karst constraints screen, the Geologic Assessment, or the full sequence through species surveys, and tell you plainly what the geology means for your schedule.