Grady Hillhouse Shares Dams Expertise in Texas WET Magazine
Thousands of small dams across Texas have outlasted their design life, need repair or replacement, and pose the risk of a “litany of unexpected consequences” if they fail, Project Engineer Grady Hillhouse, PE, writes in the Winter 2020 issue of Texas WET, the magazine of the Water Environment Association of Texas.
Grady, a member of the Water Resources Design team in the San Antonio office, shares his expert tips for dealing with the challenges in the magazine’s cover story, ”Small Dams Can Cause Big Problems."
With the average age of all the dams in the U.S. over 50 years, he writes, “Owners of small dams must recognize the hidden consequences of failure and be proactive and vigilant in maintaining the safety and integrity of their structures.”
Here’s a summary of his advice:
- Inspect Often: Although inspections aren’t a substitute for proper maintenance, they reduce risks by allowing early identification of dam safety concerns.
- Have a Plan: During a dam safety incident, an Emergency Action Plan is a critical tool to guide the owner in identifying vulnerabilities, classifying issues in terms of magnitude, notifying appropriate stakeholders, and knowing when to reach out for engineering support.
- Follow the Rules: Before considering work on a dam, understand the regulations that might apply, including those from local government, TCEQ, Texas Parks and Wildlife, the Texas Historical Commission, the General Land Office, U.S. Army Corps of Engineers and the U.S. Fish and Wildlife Service.
- Consider All the Options: In most cases, the first step should be a detailed alternatives analysis that considers advantages and disadvantages of repair, remediation, replacement or removal.
- Collect Data: Detailed site investigations, including geotechnical drilling and diving inspections, are crucial for understanding existing conditions, and historical research can provide essential insights, especially for old dams.
- Take Action: Expediency is important because structural conditions only get worse with time, and design, permitting and construction of repairs can be a lengthy process.
- Understand Costs: Remediation of small dams can involve substantial costs for engineering, legal work and permitting, in addition to construction, so evaluate all those elements and identify funding sources.
- Be Open to Innovation: Use brainstorming and charrette sessions to find less-conventional solutions that can be creative and cost-effective.
- Be Prepared for Construction: Keep contracts flexible to allow for unexpected conditions that often occur with small, historical structures, and coordinate with the engineer through construction as required by TCEQ.