During the inaugural year of the Harris-Galveston Subsidence District Water Conservation Grant Program, the District awarded almost $133,000 in matching funds to five grantees who evaluated, implemented, and promoted water conservation at the local scale, leveraging more than $400,000 towards water conservation projects in the Houston region.
The five funded projects included an innovative water loss program, installation of smart irrigation controllers for sports fields, and water conservation research on water use in the City of Houston.
- Water Loss Control: The City of League City implemented a water loss control project that used targeted leak detection to pinpoint areas of interest accompanied by field investigation and pipe repair.
- Irrigation Efficiency: Both Clear Creek Independent School District (CCISD) and Klein Independent School District (KISD) submitted irrigation efficiency projects that replaced traditional irrigation controllers with weather-based controllers along with centralized control systems for more than 50 athletic fields at two school districts.
- Water Conservation Research: University of Houston Department of Civil and Environmental Engineering and the Meadows Center for Water and the Environment at Texas State University conducted two separate research projects that investigated cost-effective best management practices and identified approaches to saving water using computer models and tracking spreadsheets.
“As our region continues to grow, the Harris-Galveston Subsidence District is committed to partnering with local communities and organizations to optimize water use and increase water efficiency to help all of our water resources go further,” Deputy General Manager Dr. Tina Petersen said.
Water Loss
Drinking water infrastructure that has been in service for decades can be a significant source of water loss through leaks. Water loss control projects can provide accountability to minimize system losses and save water.
The City of League City serves over 100,000 people and has over 500 miles of utility main lines, with 34,000 retail metered connections. The City’s water loss percentage varied from 7-15 percent over the past 10 years. Improvements in the implementation of an Advanced Metering Infrastructure (AMI) system, the installation of strategically located auto-flushing devices and an aggressive water line replacement program in older neighborhoods contributed to a reduction in water loss percentages.
To further reduce water loss, the City requested funding from the District’s grant program to implement a project which utilized proprietary multispectral satellite imagery that was paired with acoustic leak detection field surveys. This project allowed identification and repair of underground treated water leaks. This methodology has shown the potential to identify leaks faster and cheaper than traditional methods in other parts of Texas.
The City contracted with Utilis (who recently changed their name to ASTERRA) to complete four satellite fly-overs and imagery analyses. This investigation yielded 199 points of interest, which were verified by field inspectors who discovered and repaired a total of 47 leaks. The ability to locate and consolidate these areas of concern within the City’s 54 square mile boundaries and 500 plus miles pipe network allowed the City to focus resources where they would provide the highest percentage of success.
As a result of repairing the leaks on the utility side, there was a 9.1% reduction in real water loss which results in a savings of more than 92,000 gallons per day and $66,900 per year.
Lessons learned:
- While the project focused solely on the utility side, the study did identify 22 leaks on the customer side. With an average retail water price of $5.50 per 1000 gallons, water loss amounts to $1,140 per year to each customer. This highlights future opportunities to provide that data to residents.
- 93% of leaks were non-surfacing or not visible at the surface which highlights the impact of using remote sensing technology to identify subsurface leaks.
- Systems with a high percentage of PVC distribution piping should be aware that traditional acoustic leak detection methods does have limitations. Because of this, he team emphasized it’s imperative to hire the most qualified “boots on the ground” leak detection group to perform field evaluations.
Irrigation Efficiency
Outdoor watering can be a significant use of water, especially when it comes to keeping athletic fields green and healthy. Clear Creek Independent School District (CCISD) and Klein Independent School District (KISD), which serve more than 90,000 students in their Districts, requested funding from the grant program to replace traditional irrigation controllers with smart weather-based irrigation controllers for their athletic fields along with centralized control systems for more than 50 athletic fields at the two school districts.
These projects have a direct water savings impact and are projected to reduce athletic field water use by 25 to 35 percent each year for the school districts. Information on water use will be gathered from the two school districts for several years to quantify just how much water is being saved by these projects.
Lessons learned:
- Controllers not only saved water, but saved maintenance staff time as well.
- Important to consider IT integration with “smart” irrigation controllers. Coordination between departments is critical to ensure water savings are achieved.
- Even with smart meters – education is needed! Hydrometers (i.e., soil moisture meters) can be used to determine if brown patch signifies the need for additional water or possibly overwatering.
Water Conservation Research
Water conservation research is an important tool in furthering the efficient use of water. The two research studies funded by the District examined the most cost-effective water conservation measures for each structure type and identified approaches to saving water using computer models and tracking spreadsheets.
The University of Houston developed a model that explored land-use based water demand factors, including indoor versus outdoor use, and generated water conservation scenarios. This land-based model identified toilet, shower, and faucet (in multi- and single-family residential use) as the highest water demand end uses for the study area in northwest Houston.
The City of Houston partnered with The Meadows Center for Water and the Environment to conduct a research project aimed at estimating residential, commercial/institutional, and outdoor water use conservation potential using the Alliance for Water Efficiency’s Conservation Tracking Tool. The study projected a 5.7% decrease in total water demand by 2040 if the selected scenarios are implemented by the City of Houston.
Lessons learned:
- Land use models help customize water conservation strategies based on location. For example, the study highlighted that multi-family residential areas typically use more water via outdated toilets and can stand to receive the most cost-effective water conservation savings by upgrading to high-efficiency (HE) toilets.
- Meadows Center showed that highest cost/benefit ration conservation measures are residential HE toilets and LF showerheads for both multi-family and single-family use.
2020 Grant Funding Breakdown
| Grantee | Grantee Cost | HGSD Grant Funding |
|---|---|---|
| City of League City | $49,580.00 | $49,580.00 |
| Klein ISD | $32,500.00 | $32,500.00 |
| Clear Creek ISD | $21,199.00 | $21,199.00 |
| University of Houston | $24,228.00 | $12,114.00 |
| Meadows Center / City of Houston | $39,214.00 | $17,545.97 |
| Total | $166,721.00 | $132,938.97 |