Combined water management zones take shape

CCGCD Graphic.
CCGCD Graphic.

By Lisa Morton

The Culberson County Groundwater District (CCGCD) got back to work after cancelling their regular meeting in April having had their last meeting in March, due to the Coronavirus stay-at-home orders. The CCGCD Board held a virtual meeting on May 13th at 2:00 p.m. via a large monitor at the District office.

Under Public Comment, Geologist Steve Finch, on behalf of the Koehn Ranches, made his case to keep the property, which is located 14 miles southeast of Van Horn, under the Michigan Flats Management Zone. After asking for a compromise on the line for Michigan Flats, Board member Lacey Koehn, who also holds an interest in the Koehn Ranches, made a request to delete any reference to eliminate Michigan Flat in the proposed Rules. Koehn cited recent geological studies submitted to the Groundwater District in March by their representative Steve Finch that she claims are also a resource of the Texas Water Development Board (TWDB), in essence ignoring the credentials of the Technical Memorandum of March 3, 2020 prepared by District Engineer Dr. Al Blair.

In the 2012 Culberson County Groundwater Management Rules, the division between the management areas was selected to match the path of Interstate 10 as a “bright-line” that separated three distinct irrigated areas. The three, at the time, were Lobo Flat, Wild Horse Flat, and Michigan Flat. Determination of the inter-management area boundaries based on hydrogeology was postponed until the next major revision of the District Rules; the report in question.

Review of Finch’s 2020 Report (as taken from the March 3, 2020 Technical Memorandum Proposed Merging of Michigan Flat with Wildhorse Flat Groundwater Management Area 

McGinnis Lochridge retained Steve Finch of John Shoemaker & Associates, Inc to evaluate the proposed changes to the management areas in the District’s rules and management plan on behalf of the Koehn Ranches in Michigan Flat. His finding in his 2020 report were: 

  1. “Michigan Flat and Wild Horse Flat are unique sub-basins with separate irrigation zones, which provided justification for keeping them as separate management zones.”
  2. “Combining Michigan Flat with Wild Horse Flat into one Management Zone will potentially create a greater degree of shortage sharing for water right holders in Michigan Flat.”
  3. “Rates of drawdown resulting from exercising of existing production permits will differ between Wild Horse Flat and Michigan Flat, because of the relation of aquifer size, well spacing, and HUPPs.”
  4. “Wild Horse sub basin has its own irrigation area that is over-allocated and experiencing draw down, which justifies maintaining it as a separate Management Zone.”  

Finding 1: Michigan Flat and Wild Horse Flat each has separate irrigated areas as shown in Figure 3 with approximately 5 miles of unirrigated land located between the two closest irrigation fields of each area. Currently, the District has a pending application for irrigation of approximately 960 acres of land located approximately 1.5 miles north of Interstate 10 and the Kohen Ranch (in between the Michigan Flat and Wild Horse Flat irrigated areas). 

Finding 2: There has been no proposed curtailment of Historical Use Production Permits in either Michigan Flat or Wild Horse Flat areas. The groundwater elevations changes in both areas are well within the District’s Desired Future Conditions. 

Finding 3: The rate of change in groundwater elevations in is proportional to the amount of pumping in each area. From 2005 to 2020 the drawdown in Wildhorse Flat (Orchard Well) has been 16.9 feet or approximately 1.1 feet per year. This well is located in a pecan orchard that has been irrigated every year since 2005. From 2016 through 2020 the drawdown in the Michigan-Flat (Bridge Well) has been 1.6 feet or approximately 0.4 feet per year. The annual amount of irrigated land in Michigan Flat has varied from approximately 100 acres (2018) to approximately 2,700 acres (2015). 

Finding 4: The District’s determination of the annual allocation for Historic Use Production Permits is based on the amount of actual groundwater production and the Desired Future Conditions for the aquifer of a maximum annual decline of 1.56 feet averaged over the entire management areas. Currently the rate of decline in the heavily pumped area is less than 1.56 feet per year, and the rate of decline over the entire Wild Horse Management area is much less. 

Figure 2: In Finch’s 2020 report Figure 2 shows the depth to water for three wells, two of which are in Wild Horse Flat (Texas State Well Nos. 47-51-804 and 47-51-902) and one in Michigan Flat (Texas State Well No. 47-60-701). The depth to water must be converted to groundwater elevation to have value in determining if the wells are in different aquifers. The land within the Michigan Flat area is higher in elevation than in Wild Horse Flat. The well in Michigan Flat has a surface elevation of 3907 ft MSEL. The 47-51-804 well in Wild Horse Flat has a surface elevation of 3742 ft MSEL or 165 feet lower than the well in Michigan Flat. The depth to water differences shown in Figure 2 are approximately 165 feet different corresponding to the difference in surface elevation and not groundwater elevation.

Board member George Strickenhausen thanked the Rules Committee for their work in fine-tuning the rules and said he “believes the geological boundary should not be eliminated for convenience” and that the two zones are “significantly separate”. CCGCD General Manager Summer Webb continues to stand by the work of the Rules Committee that determines the best way to manage the entire aquifer from data the District is tasked to collect. 

Ultimately, the new rules were passed with board members Cottrell, Brewster, and Parada voting in favor; Strickhausen and Koehn opposed the motion. 

During another Agenda Item for Public Comment, Richard Koehn asked for information regarding the Administratively Complete NHUPP Application for TXDOT. GM Webb told Koehn that the information is available upon request.

In other business, the CCGCD:

Metering Program was reimbursed $50,000 from Texas Water Development Board

Discussed NHUPP Application for TXDOT and set a Hearing date for July 8, 2020.

Approved Tax Re-sale bids. 

Approved a $250 sponsorship fee to set-up Cybersecurity Sponsorships with TAGD

Reported Field Tech Reports were available online for 2019

Paid Bills, approved Budget Line Items and Bank Reconciliations

Discussed agenda items for June Meeting.