4E. Recommended Water Management Strategies for Wholesale Water Providers As discussed in earlier chapters, the Region C Water Planning Group has designated 41 wholesale water providers – 12 classified as regional wholesale water providers and 29 classified as local wholesale water providers. The majority of the water supplied in Region C is provided by the 12 regional wholesale water providers, nine of which are based in the region, with three located in other regions. Collectively, the nine regional wholesale water providers located in Region C (Dallas Water Utilities, Tarrant Regional Water District, North Texas Municipal Water District, Fort Worth, Upper Trinity Regional Water District, Greater Texoma Utility Authority, Trinity River Authority, Corsicana, and Dallas County Park Cities Municipal Utility District) provide over 90 percent of the total water needs in the region. These entities are expected to continue to provide over 90 percent of the water supply for Region C through 2060, and they will also develop most of the new supplies for the region during that time period. The three regional wholesale water providers located in other regions (Sabine River Authority, Sulphur River Water District, and Upper Neches River Municipal Water Authority) also play an important role in water supply for Region C. These providers own and/or operate major sources of current water supply for Region C. The 29 local wholesale water providers supply considerable quantities of water to water user groups in their areas and are expected to continue meeting these local water needs. Several of the local wholesale providers obtain water exclusively from a regional wholesale provider. It is assumed that these entities will continue to purchase water from the regional provider. Other local water providers will develop new water management strategies to meet their needs and those of their customers. This section discusses the recommended water supply plans for each regional wholesale water provider (Section 4E.1) and local wholesale water provider (Section 4E.2). Evaluations of specific water management strategies are included in Appendix P, and detailed costs are shown in Appendix Q. Cost estimates for conservation strategies were developed for individual water user groups and are discussed in Chapter 4B and shown in 2011 Region C Water Plan 4E.1 Appendix Q. Detailed listings of demands by customer for each of the wholesale water providers and the projected need for additional water by provider are included in Appendix H. In general, the Region C Water Planning Group has adopted strategies that will develop a total supply for wholesale water providers between 20 and 30 percent greater than the projected demands. This policy was adopted for several reasons: The additional supply provides a margin of safety in case climate change reduces the supply available from existing sources. The additional supply provides a margin of safety in case of a drought more severe than the previous drought of record, on which yield estimates are based. The additional supply provides a margin of safety in case demands grow more rapidly than projected. The additional supply provides a margin of safety in case some proposed management strategies cannot be developed or are developed more slowly than anticipated. 4E.1 Recommended Strategies for Regional Wholesale Water Providers The recommended strategies for the regional wholesale water providers include conservation, reuse, connections to existing sources already under contract, connections to other existing sources, and the development of new supplies. These strategies are described in greater detail below. Strategies for Multiple Wholesale Water Providers Marvin Nichols Reservoir. The Marvin Nichols Reservoir is a recommended strategy for the Tarrant Regional Water District (TRWD), the North Texas Municipal Water District (NTMWD) and the Upper Trinity Regional Water District (UTRWD). Marvin Nichols Reservoir was a recommended project in the 2001 Region C Water Plan(4) and the 2006 Region C Water Plan(9). The project would provide a large source of additional supply for the Metroplex at a relatively low cost. Marvin Nichols Reservoir is an alternative source of supply for Dallas Water Utilities and the City of Irving. The total yield of Marvin Nichols Reservoir is 612,300 acre‐feet per year, assuming that Lake Ralph Hall is senior to Marvin Nichols Reservoir and that Marvin Nichols Reservoir is operated as a system with Wright 2011 Region C Water Plan 4E.2 Patman Lake. The division of the 489,840 acre‐feet per year assumed to be available to Region C from the reservoir in the recommended strategy is: 280,000 acre‐feet per year for Tarrant Regional Water District 174,840 acre‐feet per year for North Texas Municipal Water District 35,000 acre‐feet per year for Upper Trinity Regional Water District. The delivery system from Marvin Nichols Reservoir (which accounts for three‐quarters of the total cost of the project) will be developed in phases. Phase 1 would be developed by 2030 and would include the reservoir and the initial pipelines and pump stations. Phase 2, planned for 2050, includes parallel pipelines and additional pump stations to deliver the remainder of the supply from the project. Toledo Bend Reservoir. The use of water from Toledo Bend Reservoir in East Texas for water supply in North Texas is a recommended strategy for the Tarrant Regional Water District and North Texas Municipal Water District in Region C. Toledo Bend Reservoir is an alternative strategy for Dallas Water Utilities and Upper Trinity Regional Water District. For the recommended strategy with participation from the NTMWD and the TRWD, the project would include the delivery of 500,000 acre‐feet per year of water: 100,000 acre‐feet per year for the Sabine River Authority in the upper Sabine Basin (North East Texas Region, Region D) 200,000 acre‐feet per year for Tarrant Regional Water District 200,000 acre‐feet per year for North Texas Municipal Water District. The facilities to deliver the water would be developed in phases, with Phase 1 planned for 2050 and Phase 2 planned after 2060. Oklahoma. Several wholesale water providers in the Metroplex have been pursuing the purchase of water from Oklahoma. At the present time, the Oklahoma Legislature has established a temporary moratorium on the export of water from the state. The Tarrant Regional Water District is pursuing a case in Federal Court to determine whether this moratorium can be overturned. For the long term, Oklahoma remains a promising source of water supply for Region C. At this time, water from Oklahoma is a recommended strategy for the North Texas Municipal Water District, the Tarrant Regional Water District, 2011 Region C Water Plan 4E.3 and the Upper Trinity Regional Water District. (Water from Oklahoma is also a recommended strategy for the City of Irving, which is not a wholesale water provider.) Water from Oklahoma is an alternative strategy for Dallas Water Utilities. There are two recommended projects from Oklahoma. Irving plans to get 25,000 acre‐feet per year from Oklahoma by 2030. The project for NTMWD, TRWD, and UTRWD is planned for 2060 and includes 50,000 acre‐feet per year each for TRWD and NTMWD and 15,000 acre‐feet per year for UTRWD. Dallas Water Utilities Dallas Water Utilities (DWU) provides treated and raw water for most of the demands in Dallas County and for demands in several surrounding counties. Since the 2006 Region C Water Plan was completed, DWU has constructed a pipeline from Lake Fork Reservoir to Lake Tawakoni and a Lake Fork Pump Station, allowing the use of some of the supplies in Lake Fork. DWU has also secured agreements with several entities for the use of return flows. The water demands on DWU are projected to increase from 607,000 acre‐feet per year in 2010 to 994,000 acre‐feet per year by 2060. The supply currently available to DWU is slightly less than 560,000 acre‐feet per year, which includes 49,800 acre‐feet per year from a temporary right for additional water from Lake Ray Hubbard that Dallas currently holds and which will expire December 31, 2011. DWU’s current supply is anticipated to decrease to slightly over 543,000 acre‐feet per year by 2060. As a result, DWU will need to develop 49,000 acre‐feet per year of additional water supplies by 2010 to meet projected demands and 451,000 acre‐feet per year of additional water supplies by 2060. Some of these needs will be met by conservation and reuse and the connection of existing sources currently under contract. Twenty‐four potentially feasible water management strategies for new supplies were identified and evaluated for DWU. Figure 4E.1 shows the unit cost for each strategy, and the full evaluations are summarized in Appendix P. The recommended water management strategies for DWU are as follows: 2011 Region C Water Plan 4E.4 2 011 Figure 4E.1 Region Unit Costs of Potentially Feasible Strategies for DWU C $5.00 Water $7.78 $4.50 Plan $4.00 4E.5 $3.50 Gallons $3.00 $2.50 Thousand $2.00 per $1.50 Cost $1.00 $0.50 $0.00 Recommended Strategies Alternative Strategies Other Strategies Conservation Additional Dry Year Supply Additional Supply for Operational Efficiency from Lake Ray Hubbard (2011) Main Stem Trinity River Pump Station (Lake Ray Hubbard Reuse ‐ 2013) Direct Non‐Potable Reuse (2015) Additional Pipeline from Lake Tawakoni (2015) Connect Lake Palestine (Integrated Pipeline with TRWD ‐ 2018) Wright Patman Lake – Flood Pool Reallocation (2035) Lake Fastrill Replacement (2055) Southwest Treated Water Pipeline Water Treatment Plant Expansions These strategies are discussed individually below. DWU Conservation. The conservation savings for DWU’s retail and wholesale customers are based on the Region C recommended water conservation program.