While many cities and water authorities in the Greater Houston area are working to reduce their groundwater usage to meet federal mandates and transition to surface water, the city of Katy is taking a different approach.

“Katy is farther west than some of those other cities converting to surface water,” Katy City Engineer David Leyendecker said. “We don’t have some of those options in this area so our situation is more unique in that regard.”

According to the Texas Water Development Board’s 2015 water use survey, most of the water used in Texas comes from one of two places: groundwater wells or surface water. Groundwater, which accounts for 57 percent of the use, is extracted from underground aquifers. Surface water, which accounts for 40 percent of use, is extracted from lakes, streams and rivers and then treated in purification plants.

The case for drilling

Instead of moving to reduce groundwater usage, city officials recently approved plans for and began drilling another well. This well, located at 27575 Highway Blvd., is the sixth well plant owned and operated by the city of Katy.

Together, the six wells have a ground storage capacity of 5.5 million gallons of water, according to the city’s annual drinking water report. All of the drinking water in Katy is obtained from these groundwater sources.

Despite being included in two water authorities that have been tasked with meeting federal mandates about reducing groundwater usage, the city of Katy is too far from any accessible surface water, Leyendecker said.

“In the near future, [using surface water] is not feasible,” he said. “There’s no water to get.”

Much of the available surface water rights in the Greater Houston area go toward Houston, he said. So much so that the majority of other cities using surface water have to go through Houston to get it.

The new well is projected to cost around $700,000 and was financed through the city of Katy water and sewer surplus fund, Leyendecker said.

City officials commissioned an environmental study from hydrogeologist William Hutchinson prior to permit acquisition and construction of the well. The city of Katy is a part of the Bluebonnet Groundwater Conservation District and as such must follow specific BGCD mandates before gaining approval for construction.

As part of the permit application process, the BGCD rules require applicants to submit two hydrogeologic reports for nonexempt wells. The reports typically include information addressing the effects of the proposed well, including area of influence, recovery time and subsidence potential, according to the BGCD website.

Subsidence is a gradual decline in land elevation as a result of pumping water from underground sources. The Greater Katy area has experience subsidence at a rate of nearly 1 inch per year for a total of 7.2 inches in the past eight years, according to data from the subsidence districts.

Hutchinson, a state-licensed engineer and geoscientist, examined the potential for subsidence caused by pumping groundwater using existing regional information and data. The proposed well will be between 560 feet in depth and will draw water from both the Chicot and Evangeline aquifers.

The well is projected to produce 125 million gallons of water per year and 238 gallons per minute, according to the report. Using simulations from registered well locations to project future conditions, Hutchinson also concluded subsidence caused by the well would total less than 1 foot and, as such, would not cause an increase in overall subsidence levels.

After construction of the well is complete, BGCD rules also mandate that city officials must complete a second report detailing results of the drilling, including drawdown and subsidence, as well as water quality tests.

The other five wells located in the Katy area fall under the jurisdiction of the West Harris County Regional Water Authority and the North Fort Bend Water Authority.

Water mandates

The Texas Legislature created the WHCRWA and the NFBWA in 2005 in order to manage water and conservation efforts in the area. The authorities’ mission also includes controlling and reducing subsidence.

“[Subsidence is] a pretty substantial problem if you don’t take it early on,” said Michael Turco, Fort Bend and Harris-Galveston subsidence district general manager.

The west side of the city of Katy has not experienced a significant amount of subsidence in the last 40 years, Leyendecker said. Based on the latest well study, officials have no reason to believe that will not continue to be the case, he said.

In order to reduce subsidence in the Greater Houston area and also meet the needs of growing communities like the unincorporated Katy area, the two water authorities joined together to fund the upcoming Surface Water Supply Project, WHCRWA Engineer Wayne Ahrens said.

The project will bring water from Lake Houston through an 8-foot wide, 39-mile long pipeline that will provide surface water to both authorities, according to the surface water website. Two pump stations will also accompany the pipeline project.

The two water authorities will share the total estimated $680 million cost to build the pipeline with the WHCRWA contributing a share of $375 million and the NFBWA providing its share of $245 million, according to the authority websites.

Design for the pipeline began in 2016. Construction is scheduled to begin in 2018 and delivery of surface water to customers is expected to begin in 2020, Ahrens said.

The NFBWA covers the Katy area south of I-10. The WHCRWA’s boundaries cover the Katy area north of I-10 and some area south of I-10, extending west along the interstate past the Grand Parkway and into the city of Katy.

“Being in two water authorities and three counties and one conservation district is a tricky thing to manage,” Leyendecker said.

According to the Fort Bend Subsidence District’s 2013 Regulatory Plan, which establishes policies in the area of groundwater regulation, cities in regulatory area A, generally those in north Fort Bend County like Sugar Land, are required to reduce groundwater withdrawals by 30 percent in 2016. An additional 30 percent must be reduced by 2025.

Cities in regulatory area B of the district have no scheduled reductions at this time. Cities in area B are, generally, in south and west Fort Bend County.

The Katy area falls into regulatory area A of the Fort Bend Subsidence District and regulatory area 3 of the Harris-Galveston Subsidence District. The new well is being built in Waller County, which does not have a subsidence district.

Waller County is instead regulated by the Bluebonnet Groundwater Conservation District. The difference between a subsidence district and a conservation district is subsidence authorities address the issue after the fact, BGCD General Manager Zach Holland said.

“Groundwater conservation districts are on the other side of things,” Holland said. “If I’m doing my job, I’m never going to cause or knowingly contribute to subsidence. We’re more preventative than remedial.”

Because the new well is in Waller County, it is exempt from groundwater reduction mandates and fees. However, the city of Katy does have to pay pumpage fees for the city-owned wells located in the Fort Bend and Harris county subsidence districts, Leyendecker said.

“Those fees go back into the water authority and help pay for other cities to get surface water,” he said.

Katy pays the WHCRWA around $2.45 per 1,000 gallons of ground water pumped from nonexempt wells. The NFBWA charges $3.05 per 1,000 gallons of water.

City of Katy residents pay a WHCRWA fee of $1.43 per 1,000 gallons used as part of their monthly water bill, according to utility billing documents. The rate was $1.23 last year and was recently increased by 20 cents to the existing rate.

As for the future of surface water in the Katy area, Leyendecker said there are a few more local wells city officials have their eye on as the need for water grows.

“These are nice places that everyone wants to move into,” Turco said. “With that increase in population comes an increased need for water.”