REGION H WATER PLANNING GROUP MEETING
OCTOBER 6, 1999
CITY HALL, CONROE, TEXAS
MEMBERS PRESENT: James Adams, Chairman, Roosevelt Alexander, John Bartos, Judge Mark Evans, Mary Alice Gonzalez, Commissioner Jack Harris, Davis Jenkins, Carolyn Johnson, Councilman Tom Manison, Marvin Marcell, James Morrison, James Murray, Ronald Neighbors, Tom Ray, Ernest Rebuck, Jack Searcy, Jr., Michael Sullivan, Steve Tyler, Danny Vance, C. Harold Wallace, Kerry Whelan.
PRESIDING: James Adams, Chairman
Substitutes: Doyle McAdams for Robert Bruner, Jimmie Schindewolf for Judge Robert Eckels, Ron Hudson for Frederick Perrenot, Jace Houston for William Teer. David Alders, representing Region I, present. Lacy Fryer, not present, new representative for the Department of Agriculture.
APPROVE MINUTES OF SEPTEMBER 1, 1999 MEETING:
Motioned to accept by Danny Vance. Seconded by Carolyn Johnson.
PRESENTATION BY CONSULTANTS, TABLES I AND II, POPULATION AND WATER DEMANDS:
Mark Lowry presented a copy of the numbers approved by The Water Development Board. Appendix A, Tables I and II, in requested format was broken down by basin according to the 1997 Water Plan with allocation of increased population rolled into water demand.
The way the process is currently configured does not allow nonwater supply demands in the 13 tables. Environmental flows are so important, it is suggested that environmental demands be added as a line item. The Galveston Bay Freshwater Inflows Group is studying this and will present viable numbers. One set of numbers presented by state water agencies is 5.2 million acre feet for freshwater inflows in the Galveston Bay at annualized median-flow conditions. An alternative set of numbers called, "Critical Drought Flows" has not been generated for Galveston Bay, but Matagorda Bay, the Lower Colorado, and Lavaca Navidad have been agreed upon.
Right now the tie between reservoir yield and median environmental flows cannot be made because the numbers are too high.
The problem with the inflows is the distribution into the bay and determining where the water needs to be coming in; because if it all comes down the Ship Channel, you have total freshwater in the upper end and you do not have the saline content you need. Much of the inflows into Galveston Bay are the return flows coming from the water usage in the Houston area.
If you made the environmental flows as a demand on Table II, it would be incumbent to come back with a recommendation on management strategy on how to meet those environmental flows. When doing a regionwide water planning effort, freshwater inflows in Galveston Bay are important. The current contract has funding and scope to allow for this study.
Motioned by John Bartos to include the demand figures for environmental flows as a water demand; that the consultants work with GBFIG to come up with a way to do that and also to satisfy those flows.
Environmental flows are required to be considered by this Group. The motion is intended to add these figures into the water demand and to come up with strategies to try to solve them. This Group would have to approve any numbers and strategies.
Seconded by Jenkins.
Discussion: The committee will have to agree that these numbers are the legitimate demands and that there will be allocations to be incorporated into this plan, and that no committed water rights are going to be taken away in order to give to the environmental flows. New reservoirs must consider environmental flows, and then management strategies will consider return flows. A management strategy has to be resolved at a higher level than just Region H.
Table III included the five major water providers and the first tier of customers or contractees. These numbers were presented for review and feedback. The intent was to find out how much water is committed by the major water providers in the region. The Contract end dates are matched up with demand and supply. The assumption was made that all contracts will automatically be renewed. If the contract has an end date, the end date should be included.
Suggestion was made to add acre feet to the legend.
The Water Development Board asked for this table to be a firm yield, not legally obligated for contract water, but for hydrological purposes for the drought records.
If it says "yes" it means that demand is expected to be available. If "no", this supply has less than 100 percent reliability. The contingency in the contracts provides for prorating. It does not guarantee an amount. Add a footnote that the sources are drought of record for a firm yield.
Water conservation drought management plans submitted to the TNRCC required proportional use in the event of a severe drought. If it is based on a firm yield, the number is already prorated and you cannot sell more firm yield than the reservoir is capable of producing.
Total water usage by the five major providers is 60 percent or more. Demand numbers are used but are less than the contracted amount. If the contract makes the customer pay a penalty for using more water than allowed by contract, that additional water is not included here but will be included in Table V as demand versus supply comparison by the user. A footnote indicates that the amounts are contracted for wholesale customers unless it specifies serving retail customers. Zero means no contracts.
Handouts were provided on Lake Millican.
PRESENTATION BY MARK KASMAREK, USGS, MODEL OF AQUIFERS:
The slide showed the model study areas and covered the City of Houston, Harris County, and most of Region H parallel to the coast. Gulf Coast aquifer system is comprised of the Chicot, Evangeline, and Jasper aquifers. The blue and green showed the down dip limits of freshwater. The Chicot overlies the Evangeline and they are called stacked sequences. It is termed a "leaky aquifer," meaning that the water can fill both ways because there are no confining sediments between the aquifers. All of the aquifer systems run parallel to the coastal bend and go almost to Florida and down towards Brownsville.
The water level change map showed changes of water levels in wells from 1977 to 1999. Blue contours indicated water levels had risen as much as 180 feet due to cessation of pumpage since 1977. Red contours indicated water levels had declined as much as 120 feet since 1977. Groundwater withdrawal or stress in the system had migrated from pumping a lot of water near the Ship Channel. As they have gone to surface water, some of that is recovered. Sand and clay layers release water when the aquifer is stressed by the pumpage. When the clay releases water, these layered beds compact resulting in land surface subsidence.
The red and black dashed lines are measured water levels for the Chicot for 1996. The contour is 50 feet with an excellent match between the measured and simulated water level heads. Negative 200 in the center, negative 200 measured and simulated. The simulated levels are based on altitude relative to sea level. For the Evangeline aquifer we have an excellent water level match using the model.
To simulate the numbers, we had to go back to the mid 1970s at the founding of the Houston/Galveston Coastal Subsidence District, where there were maximum declines and calibrated to that time the intervals so we had a good head match on hydrograph with a maximum decline that had occurred and then brought those out to 1996. Initial starting period was 1890. We calibrated with heads, subsidence, long and short-term water levels.
The groundwater model does an excellent job of simulating water levels and land surface subsidence when compared to actual or measured values. The model is a digital model using MOD flow with an intervet storage package developed specifically for this geological environment. This model is a clays and sands dewatered configured component of subsidence and how much water is released calibrated with heads, subsidence, and aquifer parameters. The model operates as nature has it or as stressed induced from pumpage. When designing a model, we get away from areas being pumped so that we have a quiescent boundary so it is not affected by boundary conditions that could make it an unsolvable mathematical solution.
The data sets developed will be available for Region H and others. The data sets contain the tops and basis of both the Chicot and Evangeline aquifers, the transpassivity or the speed that it moves horizontally, sand and clay thickness, sand and clay storage, vertical conducting, water budget and pumpage information from the Texas Water Development Board and the Harris/Galveston Coastal Subsidence District. This model showed the loss of reservoir capacity caused by subsidence and covered 21 counties from Matagorda, Walker and Grimes, to Austin County.
This model will be used as a management tool with optimization software to optimize well fields and integrate the subsidence component. The data sets will be in the public domain.
It is the intention of the City of Houston and the USGS to continue to use groundwater within the limits of the Subsidence Districts' permits, but to manage that resource and ensure that the well fields have maximized withdrawal, while minimizing adverse impact on the aquifer declines or the issue of subsidence.
Woody Woodrow with Parks and Wildlife: The unique stream report is not complete. Any of the streams put on the report fall into at least two of the established criteria in SB1. The preliminary list conflicts with some of the potential reservoir sites. We will make those observations, present that to the committee; and it is up to the committee to decide how to list any, all, or none of both unique stream segments and unique reservoir sites. There will be maps and photographs with text description of why it meets the list. If there are streams that the Group might think meets this criteria, it is for the Group to decide what they want to do with them.
Mr. Rebuck mentioned there is a guidance assignment for October 4th, for both Table III and Table IV. There are three things here: December 17, 1998, the orange line, grant monies became available. January 5, 2001, is the completion date. We are about 40 percent complete in terms of time available for approval of the regional water plans. The green line is based on funding, and that is based on a percent. "H" is paid bills to Brown & Root. The purple bar is the progress. Half is the task completed, the other half are the four quarterly reports. The Scope of Work is one, and then you go to all the chapters. Table III has been a challenge, and Chapter II is not nailed down yet. A lot depends on how fast the consultants give the Board the hard data to work with and how fast we review it and come to terms and agreement.
J.D. Beffort mentioned a desalination project in Tampa Bay. Water desalt there is $2 per 1000 gallons, about 1/3 or 1/4 the cost discussed in the TransTexas Study. Handouts were distributed on factors for seawater desalination in Texas. The results to be incorporated into the regional plans. The new study through Region N, in conjunction with the Nueces River Authority, required teams to incorporate consultants, desalt folks, and the power industry. The concept will be to take cooling water that has gone through a condenser and use that as feed water for the desalt plant to achieve cost savings as well as utilizing water already available in reverse osmosis by raising the temperature of the water to increase the amount of water that goes through the membrane.
November 3, 1999
6th Floor of City Hall