Executive Summary. ES-1

1.0            Introduction  1

1.1            Current Upper Basin Supplies  1

1.2            Comprehensive Sabine Watershed Management Plan  1

1.3            Other Studies  2

1.4            Scope of Work. 3

2.0       Current Conditions. 4

2.1            Projected Demands. 4

2.2            Existing SRA Supplies  5

2.3            Future System Yield  7

2.4            Summary of Additional Water Supply Needs  12

3.0            Alternatives to Meet Identified Shortages. 14

3.1            Prairie Creek Reservoir 14

3.2            Pipeline From Toledo Bend Reservoir 14

3.3            Local Groundwater 17

3.4            Temporary Use of Lake Cherokee Water Supply  18

3.5            Temporary Use of Dallas Lake Fork Supply  18

3.6       Use of Dallas Lake Fork In-Basin Supply  19

3.7            Pipeline from Lake Fork to Lake Tawakoni 20

3.8            Additional Water Delivery Costs  20

4.0            Summary and Conclusions. 22


 

List of Tables

Table 1.  SRA Upper Basin Demands by Customer Type (MGD) 4

Table 2.  SRA Upper Basin Demand by Geographic Area (MGD) 4

Table 3.  Firm Yield of Lake Tawakoni and Lake Fork (acre-feet per year) 5

Table 4.  Firm Yield of Lake Tawakoni and Lake Fork (MGD) 7

Table 5.  SRA Upper Basin Yield Under Various Scenarios (acre-feet per year) 8

Table 6.  SRA Upper Basin Yield Under Various Scenarios (MGD) 9

Table 7.  Additional Supplies Needed for Demand Scenarios (MGD) 12

Table 8.  Prairie Creek Reservoir Cost Summary. 14

Table 9.  Toledo Bend Pipeline Alternatives. 17

Table 10.  Toledo Bend Pipeline Alternatives Cost Summary. 17

Table 11.  Proposed Groundwater Wellfields. 17

Table 12.  Potential Use of Dallas Lake Fork Supplies (MGD) 19

Table 13.  Lake Fork to Lake Tawakoni Pipeline Summary. 20

Table 14.  Additional Customer Facilities. 21

Table 15.  Summary of Additional Supply Needed (MGD) 22

Table 16.  Comparison of Long-Term Supply Alternatives (MGD) 23

 

 

List of Figures

Figure 1.  SRA Upper Basin Supply and Demand. 6

Figure 2.  Lake Fork Reservoir Storage Under Various Operations. 10

Figure 3.  Lake Tawakoni Reservoir Storage Under Various Operations. 11

Figure 4.  General Pipeline Routing. 16

 

 

 


 

Appendix

 

Appendix A.  Upper Basin Customer Demands

Appendix B.  Upper Basin System Yield Analysis

Appendix C.  Prairie Creek Reservoir

Appendix D.  Upper Basin Pipeline Analysis

Appendix E.  Upper Basin Groundwater Analysis


Executive Summary

 

In May 2002, the Sabine River Authority of Texas (SRA) authorized KBR to update and expand investigations of various methods and costs for supplying future water needs in the Upper Sabine Basin.  This report documents the analysis of SRA demands in the Upper Basin and summarizes the alternative supply strategies that were investigated for meeting those demands through year 2050.

 

Key Findings

 

The key findings associated with this study are summarized below:

 

·        Currently, existing water supplies available to the SRA in the Upper Basin include the SRA allocations of Lake Tawakoni and Lake Fork. The yield in these reservoirs is anticipated to decrease in the future due to sedimentation.

   

·        The Upper Basin is expected to have demands for water from SRA that exceed the current SRA supply within the next 10 to 20 years.

 

o       Demand Scenario No. 1. Demands associated with existing SRA contracts and requests for additional supplies, year 2050 new supply needed: 42.5 MGD.

o       Demand Scenario No. 2. Demands associated with existing SRA contracts and requests for additional supplies and additional needs identified by Senate Bill 1 Regional Planning, year 2050 new supply needed: 83.4 MGD.

·        A system yield permit that includes Lake Fork, Lake Tawakoni, and Toledo Bend Reservoir with upstream diversions to the Longview / Kilgore / Henderson area would provide 4 MGD (Million Gallons per Day) of additional supply under projected (conservative)  2050 sedimentation conditions.  The Texas Commission on Environmental Quality’s permitting process encourages system yield permits.

        

·        Short-term Supply Alternatives

 

o       Lake Cherokee.  No additional supply available under its current operation.

o       Dallas portion of Lake Fork.  Dallas is not expected to use its full allocation of Lake Fork water until 2018. This alternative provides the potential to delay construction costs associated with any of the following long‑term supply alternatives, but has considerable contracting issues to resolve between SRA and the City of Dallas.

·        Long-term Supply Alternatives

 

o       Water Conservation. Water conservation is an integral element of SRA’s commitment to provide adequate supplies of high-quality water to municipal, industrial, agricultural, and recreational users of Sabine Basin water.  Water conservation is accounted for in the demand projections used in this study.

o       Dallas “In-basin“ Portion of Lake Fork. According to the Lake Fork water right, 10.6 MGD of the Dallas allocation cannot be transferred out of the Sabine Basin. This supply could be acquired by SRA through contractual negotiations and used in the Upper Basin.  This supply could also be reserved to maintain lake levels in Lake Fork for recreational uses. There are significant contracting issues to resolve between SRA and the City of Dallas before this water can be considered a viable option for meeting future demands.

o       Groundwater Development. The Senate Bill 1 Regional Plans identify approximately 45 MGD of potential available supply in the Carrizo Wilcox Aquifer upstream of the Longview/Kilgore/Henderson area. There are significant issues that must still be addressed before groundwater can be considered a viable option for meeting future demands.  These issues include water quality, impact on surrounding well performance, and regulatory issues.

o       Prairie Creek Reservoir. The maximum reservoir yield of 26.5 MGD (reservoir with high-flow scalping diversions) is not sufficient to meet either of the year 2050 Upper Basin demand scenarios.

o       Toledo Bend Reservoir Pipeline. A pipeline conveyance project from existing supplies in Toledo Bend Reservoir can be implemented in stages to meet increasing demands through 2050.  This project provides flexibility for construction dates of segments to be adjusted to meet a variety of potential future demands.

·        To meet projected year 2050 demands, Prairie Creek Reservoir, groundwater development, and/or a pipeline from Toledo Bend Reservoir will be needed.

·        The only alternative that alone can meet the needs associated with the two demand scenarios is a pipeline from Toledo Bend to the Longview/ Kilgore/Henderson area along with a pipeline from Lake Fork to Lake Tawakoni. 

 

·        Regardless of which identified short or long-term supply alternative is selected by SRA, there will remain a projected need to deliver water from Lake Fork to Lake Tawakoni by year 2015.

 

 

Analysis of Demand and Existing Supply

 

A survey was performed by the SRA of its existing customers, entities that have requested water from SRA, and other retail water suppliers in the Upper Basin.  SRA Upper Basin demands have been grouped into two categories: 1)  Existing Contracts and Requests;  and 2)  Existing Contracts, Requests and Additional Demands from Regional Planning. 

 

Existing supplies available to the SRA in the Upper Basin include the SRA allocations of Lake Tawakoni and Lake Fork.  The yield in these reservoirs is anticipated to decrease in the future due to sedimentation.  Table ES-1 and Figure ES-1 summarize the supplies, demands, and need for additional supplies in the Upper Basin.

 

Table ES-1.  Additional Supplies Needed for Demand Scenarios (MGD)

 

Permitted

2000

2005

2010

2020

2030

2040

2050

SRA Lake Tawakoni Supply

42.5

42.5

42.4

42.2

41.9

41.5

41.2

40.9

SRA Lake Fork Supply

50.7

46.2

45.8

45.5

44.8

44.0

43.3

42.6

Existing Supply in Lake Tawakoni & Lake Fork

93.2

88.7

88.2

87.7

86.6

85.6

84.5

83.5

Demand Scenario No. 1

 

 

 

 

 

 

 

Demands associated with Contracts & Requests

35.0

73.4

85.0

102.7

113.0

118.6

126.0

Additional Supply Needed

0.0

0.0

0.0

16.0

27.5

34.1

42.5

Demand Scenario No. 2

 

 

 

 

 

 

 

Demands associated with Contracts, Requests and Regional Planning

35.0

80.4

93.8

128.3

149.0

157.1

166.9

Additional Supply Needed

0.0

0.0

6.1

41.7

63.4

72.5

83.4

 

As part of this study, a water availability model was created to assess the potential benefit of the Sabine River Authority obtaining a system yield permit that includes Lake Fork, Lake Tawakoni and Toledo Bend Reservoir with upstream diversions in the Longview / Kilgore area.  This analysis revealed that 4 MGD of additional supply (beyond the SRA portion of the permitted amount) would be available under year 2050 sedimentation conditions and 12 MGD would be available under year 2000 sedimentation conditions.

 

Alternative Future Supplies

 

Short-term supply alternatives analyzed included Lake Cherokee and the Dallas portion of Lake Fork.  Lake Cherokee does not have any additional supply available under its current operation, which limits drawdown as necessary for power plant operation.  Dallas is not expected to use its full allocation of Lake Fork until 2018.  Prior to that, a portion of that supply could be reallocated to satisfy SRA Upper Basin needs.  Obtaining an agreement with Dallas could potentially satisfy the demands for additional supply through 2015, after which a long-term supply would be necessary.

 

Long-term alternatives to meet the 2050 projected demands of the Upper Basin considered in this study include:

 

·        The Dallas “in-basin” portion of Lake Fork.

·        Groundwater from the Carrizo-Wilcox and Queen Cities Aquifers.

·        Prairie Creek Reservoir.

·        Toledo Bend Reservoir supplies conveyed via pipeline to the Upper Basin.

 

According to the Lake Fork water right, 10.6 MGD of the Dallas allocation cannot be transferred out of the basin.  If an agreement were made with Dallas, this supply would become available to satisfy a portion of SRA’s future demand.  This supply could also be reserved to help maintain lake levels in Lake Fork for recreational uses.  The actual cost of this supply and ability to negotiate contracts for its transfer to the SRA are not known at this time; therefore, discussions should continue with the City of Dallas, but it cannot be expected to be a part of the solution to the SRA’s needs at this time.

 

Groundwater development was analyzed as a long-term supply alternative that has potential implementation benefits since well development could be staged as supplies are needed.  The Regional Plans indicate approximately 240 MGD of available supply in the Upper Basin from the Carrizo Wilcox and Queen Cities Aquifers.  Of this, approximately 45 MGD was identified upstream of the Longview / Kilgore / Henderson area based on review of the performance of existing wells and the location of potential wellfields relative to demands.  Issues associated with this alternative include:  water quality considerations related to discharge of groundwater into surface streams, bed and banks permitting requirements, and legal and political issues such as formation of groundwater conservation districts and other opposition from local government and private property owners.  Since the estimated cost for this supply is projected to be relatively low, the SRA should conduct additional analyses to confirm the availability, quality, impact on surrounding wells, and likely cost of the supplies.  If these detailed feasibility studies prove to be promising, then further investigation of the public receptivity to this alternative should be explored further.  Revision to the charter of the SRA may be required to allow significant development of groundwater resources in the Basin.  These significant issues must be addressed before groundwater can be considered a viable option for meeting future demands.

 

Development of Prairie Creek Reservoir was recommended as the most viable alternative in the Comprehensive Sabine Watershed Management Plan in 1999.  The reservoir yield was previously estimated at 19,700 acre-feet per year (17.6 MGD) if operated alone, and 29,685 acre-feet per year (26.5 MGD) when supplemented with high flow scalping diversions.  While the estimated cost is reasonable, significant issues must be addressed related to the environmental and construction permitting of such a reservoir project.  Since the available supplies from this project are limited and do not meet the projected demands but for a short period, development of other supplies will be necessary and should be investigated first.

 

The Toledo Bend Reservoir supplies are currently available and can be conveyed to the Upper Basin with limited environmental impacts or regulatory requirements.  A pipeline from Toledo Bend Reservoir can also be implemented in stages in order to meet increasing demands through 2050.  This alternative also provides flexibility to allow construction dates of segments to be adjusted in order to meet a variety of potential future demands.  The recommended pipeline routing is shown in Figure ES-2.  Various staging and supply options were investigated for this option which indicate that Toledo Bend water could be delivered to the Upper Basin for a cost ranging from $0.70 – 1.33 per 1000 gallons delivered.    This cost does not include the cost of Toledo Bend raw water supplies.  This cost is higher than other potential options, but has the advantage of much less uncertainty and risk associated with its implementation.  If additional participation in the use of Toledo Bend water can be developed to expand the pipeline capacity, the SRA cost can be reduced significantly.  Therefore, this option is the recommended approach to meeting the projected Upper Basin water supply needs.

 

In developing pipeline alternatives, an important element was the ability to phase construction and develop a plan that is flexible enough to meet changing demands through 2050.  A total of five pipeline alternatives were evaluated to meet the following demands for additional supply in order of increasing magnitude of supply:

 

TB 1.       Existing contracts plus requests for additional supply, assuming 10 MGD can be obtained from the Dallas in-basin Lake Fork allocation, resulting in year 2050 additional required supply of 32 MGD.

TB 2.       Existing contracts plus requests for additional supply, resulting in year 2050 additional required supply of 42 MGD.

TB 3.       Existing contracts, requests for additional supply and projected Regional Planning demands assuming 10 MGD can be obtained from the Dallas in-basin Lake Fork allocation, resulting in year 2050 additional required supply of 73 MGD.

TB 4.       Existing contracts, requests for additional supply and projected Regional Planning demands, resulting in year 2050 additional required supply of 83 MGD.

TB 5.       Entire Longview / Kilgore / Henderson contract demands, requests for additional supply, and projected Regional Planning demands, resulting in year 2050 additional required supply of 97 MGD.

 

 

Table ES-2 summarizes the costs associated with the long term-supply alternatives considered in this study.

 

Table ES-2.  Comparison of Long-Term Supply Alternatives

Alternative

Supply Available

(MGD)

Total Construction Cost

50 Year Life Cycle Analysis *

100 Year Life Cycle Analysis *

Average Deliveries (MGD)

Cost per 1000 gallons delivered

Average Water Sold (MGD)

Cost per 1000 gallons sold

Average Deliveries (MGD)

Cost per 1000 gallons delivered

Average Water Sold (MGD)

Cost per 1000 gallons sold

Prairie Creek Reservoir

17.6

$ 63,787,000

11.2

$ 0.71

17.6

$ 0.45

14.4

$ 0.35

17.6

$ 0.28

Reservoir With Scalping

26.5

$ 84,204,000

15.6

$ 0.69

26.5

$ 0.41

21.0

$ 0.34

26.5

$ 0.27

TB 1

32

$144,226,000

12.3

$ 1.33

30.0

$ 0.54

22.3

$ 0.61

30.0

$ 0.45

TB 2

42

$145,912,000

18.9

$ 1.05

40.0

$ 0.50

30.6

$ 0.51

40.0

$ 0.39

TB 3

73

$217,782,000

34.8

$ 0.87

60.0

$ 0.50

53.9

$ 0.50

65.0

$ 0.42

TB 4

83

$217,781,000

42.7

$ 0.80

70.0

$ 0.49

62.9

$ 0.48

75.0

$ 0.41

TB 5

97

$283,477,000

70.5

$ 0.71

70.0

$ 0.71

83.8

$ 0.47

75.0

$ 0.49

Ground water

45

$ 47,031,000

18.9

$ 0.37

 

 

 

 

 

 

TB # represents Toledo Bend Pipeline alternatives.

Groundwater unit pricing based on 30-year life cycle analysis.

*  Unit costs for Toledo Bend Alternatives do not include the cost of Toledo Bend raw water.

 

 

Lake Fork to Lake Tawakoni Pipeline

 

A pipeline from Lake Fork to Lake Tawakoni is not an alternative to be compared to the others, but is required by year 2015 to meet Upper Basin demands regardless of which alternative(s) is (are) selected. While capacity may be available in the pipeline currently being designed and constructed for the City of Dallas, costs have been developed for a 42-inch diameter pipeline which would be dedicated to the SRA demands only in order to provide a “worst case” alternative in terms of estimated costs.  This pipeline would be sufficient to meet the year 2050 average demand at Lake Tawakoni that must be met by Lake Fork of 25 MGD.  Table ES-3 shows the total construction costs and unit costs to transport water sold from Lake Fork but delivered from Lake Tawakoni.

 

Table ES-3.  Lake Fork to Lake Tawakoni Pipeline Summary

Total Construction Cost

50 Year Life Cycle Analysis

100 Year Life Cycle Analysis

Average Deliveries (MGD)

Cost per 1000 gallons delivered

Average Water Sold (MGD)

Cost per 1000 gallons sold

Average Deliveries (MGD)

Cost per 1000 gallons delivered

Average Water Sold (MGD)

Cost per 1000 gallons sold

$30,979,000

9.7

$ 0.48

25.0

$ 0.18

16.8

$ 0.22

25

$ 0.15

 

 

Recommended Actions

 

The recommended implementation activities and the potential amounts of additional long-term supply that could be made available are summarized below.

 

·        Initiate application with TCEQ for a system permit between Lake Fork, Lake Tawakoni and Toledo Bend Reservoir to allow upstream diversions from Toledo Bend Reservoir in the Longview / Kilgore / Henderson area.  (4 MGD of new supply.)

·        Pursue additional partnerships for use of Toledo Bend Reservoir supplies in order to increase the capacity of pipeline and pumping facilities and reduce the cost of the resulting water conveyance. (Up to 83 MGD of new supply.)

·        Continue negotiations with Dallas to allow SRA to use a portion of the capacity of the Dallas pipeline from Lake Fork to Lake Tawakoni.  If not successful, initiate detailed planning and begin right-of-way acquisition for a separate 42-inch diameter/ 25 MGD SRA pipeline.

Other alternatives to be considered if issues associated with them can be resolved include:

·        Continue negotiations with Dallas to allow SRA to acquire Dallas in-basin water.  (10.6 MGD of new supply.)

·        Retain the Prairie Creek Reservoir as a future element in the SRA’s Upper Basin Plan, but defer further investigations of this option pending development of further studies related to use of Toledo Bend Reservoir supplies (No new supply at this time but up to 26.5 MGD if re-initiated at a later date.)

·        Conduct feasibility studies for conjunctive use of groundwater in selected areas of the Upper Basin.  Evaluate impact on existing wells, water quality, and use of bed and banks to transfer supplies to demand areas.    (Up to 45 MGD of new supply.)

·        Obtain agreement for temporary use of Dallas Lake Fork supplies on an interim basis in order to delay construction costs associated with long-term alternatives.

 

 

 

 


1.0     Introduction

 

In May 2002, the Sabine River Authority of Texas (SRA) authorized KBR to update and expand investigations of various methods and costs for supplying future water needs in the Upper Sabine Basin.  This report documents the analysis of SRA demands in the Upper Basin and summarizes the alternative supply strategies which were investigated for meeting those demands through year 2050.

 

1.1    Current Upper Basin Supplies

 

Existing water demands in the Upper Basin are provided for through a combination of groundwater and surface water supplies.  Groundwater supplies are generally used by local municipalities and water supply corporations.  Surface water supplies in the Upper Basin include 1) direct diversions from the Sabine River; 2) the yield from small reservoirs located on tributaries to the Sabine River; and 3) two large reservoirs owned by the SRA and located in the upper reaches of the Upper Basin, Lake Fork and Lake Tawakoni. 

 

The 1985 Update of the Master Plan for the Sabine River and Tributaries in Texas (1985 Master Plan Update) included development of proposed future reservoirs in both the Upper and Lower Basins.  Several of the proposed reservoirs are located along the main stem of the Sabine River.  One such project is Waters Bluff Reservoir, located in Smith, Upshur and Wood Counties.  The yield of this project, 324,000 acre-feet per year, could meet the projected need in the Upper Basin well beyond 2050.  However, since the initial feasibility studies were conducted several factors have come into existence which reduce the potential for construction of this reservoir in the foreseeable future.  These factors include numerous land and ownership features which would be inundated by the proposed reservoir, including mitigation banks established in the area, the Little Sandy National Wildlife Refuge (a non-development conservation easement), and portions of the site which are designated as a Priority 1 bottomland hardwood area by the United States Fish and Wildlife Service.  Additional issues complicating development of this site include the presence of prehistoric cultural sites, and the scenic and recreational qualities of this segment of the Sabine River.  Finally, development of this project would also require a formal act of Congress to override the Little Sandy easement.

 

Several more recent studies relevant to future water supplies in the Upper Basin are summarized below.

 

1.2    Comprehensive Sabine Watershed Management Plan

 

This plan was prepared for the Sabine River Authority of Texas in conjunction with the Texas Water Development Board by Freese and Nichols, Brown & Root and LBG-Guyton in 1999.  The plan further updated the 1985 Master Plan Update.  The 1999 plan projected that the Upper Basin needed approximately 93,000 acre-feet per year (83 MGD) of additional supply by 2050.  The most viable source identified within that study was a staged development of Prairie Creek Reservoir.  The firm yield of the reservoir was expected to meet projected demands through 2023 and as further supply was needed, “scalping” diversions from the Sabine River were proposed to supplement the yield of the reservoir.  However, these diversions would not provide enough additional supply to meet all of the needs through 2050.  Another option suggested in this study was to supplement the supply from Prairie Creek Reservoir with a pipeline from Toledo Bend Reservoir.

 

Additional related recommendations from this plan included: water conservation; pursuing negotiations with the City of Dallas to allow for selling of water in Dallas’s Lake Fork contract that must stay in the Sabine Basin; beginning the permitting process for Prairie Creek Reservoir; reevaluating the water use demand projections; reviewing the future Water Availability Model of the Sabine River Basin to determine the current supply available for additional diversions and existing contracts; re-evaluating the need, timing, and sizing of a transmission pipeline from Toledo Bend Reservoir; pursuing discussions with various customers regarding reducing their contracted amount in order to free up those supplies for other needs; initiating discussions with Wood County regarding the possibility of converting the Wood County Lakes to water supply; and encouraging the Cities of Kilgore and Canton to work with the Texas Water Development Board (TWDB) regarding the possibility of a future “Aquifer Storage and Recovery” project.

 

1.3    Other Studies

 

The Water Availability Model (WAM) of the Sabine River Basin was developed for the Texas Natural Resources Conservation Commission (TNRCC), now Texas Commission on Environmental Quality (TCEQ), by Brown & Root in 2001 and updated in June 2002.  That study estimated the water availability for existing water rights and computed the firm yields for existing reservoirs in the Sabine River Basin. 

 

Additional regional water planning under Senate Bill One has been performed throughout the state as part of the process of creating a state water plan.  Specifically, parts of designated Regions C, D and I are located within the Upper Sabine Basin.  These regional water plans analyzed expected demands and supplies in each Region and identified shortages requiring additional supplies.  The source for additional supplies in each Region included both groundwater and surface water.   In this study, the majority of shortages that have been identified to be met by surface water are assumed to be provided by SRA.

 

A Groundwater Availability Model (GAM) of the Carizzo-Wilcox Aquifer was developed for the Texas Water Development Board and issued as a draft report in September 2002.  This GAM assesses the impact of projected groundwater use through 2050 on existing water levels and spring flows in the Carrizo-Wilcox and Queen City Aquifers.  The GAM does not address water quality issues in the aquifer.  The results of the draft GAM have been considered in the evaluation of local groundwater supplies as further described below. 

 

1.4    Scope of Work

 

The scope of work for this study consists of an evaluation of meeting Upper Basin customer requests through short-term use of committed but currently unused water supplies, and an evaluation of additional long-term supply alternatives. 

 

Phase 1, the customer contract assessment, consists of the following tasks:

 

Phase 2, the water supply source assessment, consists of the following tasks:

 


2.0    Current Conditions

 

In order to determine the additional supply needed within the Upper Basin, an evaluation of existing supplies and projected demands was performed as described in this section.

 

2.1    Projected Demands

 

As part of this study the SRA conducted a survey of its existing customers, entities which have requested water from SRA, and other retail water suppliers in the Upper Basin.  The entities surveyed provided estimated demand data, by decade, of SRA supplied water.  A summary of these demands is shown in Table 1. 

 

Table 1.  SRA Upper Basin Demands by Customer Type (MGD)

 

2000

2005

2010

2020

2030

2040

2050

Existing Customer Demand Not Exceeding Current Contracts 1

34.2

67.7

73.6

75.0

78.1

79.0

80.0

Existing Customers Demand Exceeding Current Contracts 2

0.1

2.2

7.0

22.7

29.3

33.4

39.3

Demands from Requests for Water by New Customers 3

0.7

3.5

4.3

5.0

5.6

6.2

6.7

Additional Demands from Regional Planning Projections 4

0.0

7.0

8.9

25.7

35.9

38.4

40.9

Total Demand

35.0

80.4

93.8

128.3

149.0

157.1

166.9

 

1.  Existing customers provided demand data representing the total use of SRA water, assuming any additional requests could be met.  “Existing Customer Demand Not Exceeding Current Contracts” has limited that demand to the current contract amount.  Existing contracts total approximately 93.2 MGD.

2.  “Existing Customer Demand Exceeding Current Contracts” represents the demands associated with requests for water which are above and beyond the current contract amount.

3.  “Demands from Requests for Water by New Customers” includes demands of new customers which have made requests to the SRA for water.

4.  “Additional Demands from Regional Planning Projections” are those demands from the Region D and Region I Plans which are to be met using surface water supplies that have not been identified as met by sources other than SRA, and are not already represented in a request to SRA.

 

The demands have also been grouped into the broad geographic regions around Lake Fork, Lake Tawakoni, and the downstream demand in the Longview / Kilgore / Henderson area as shown in Table 2.

 

Table 2.  SRA Upper Basin Demand by Geographic Area (MGD)

 

2000

2005

2010

2020

2030

2040

2050

Tawakoni

13.6

31.0

37.6

47.6

54.6

59.7

65.0

Fork

1.0

2.6

3.1

3.1

4.1

4.1

4.6

Longview/Kilgore/Henderson

20.4

46.8

53.1

77.7

90.2

93.3

97.3

Total All

35.0

80.4

93.8

128.3

149.0

157.1

166.9

 

 

Figure 1 provides a visual summary of the demands in the Upper Basin.  Appendix A in this report includes a technical memorandum which provides further details of the projected demands and estimated supply from existing sources in the Upper Basin. 

 

The identified future demands have been grouped into two categories: 1) “Existing Contracts and Requests”, and 2) “Existing Contracts, Requests and Regional Planning”.  Because the demand from Regional Planning includes demands that are not associated with any particular entity (for example, Gregg County Manufacturing) and therefore are less likely to have contracts executed in the near term, the demands have been grouped in this manner. 

 

Existing contracts total approximately 93 MGD, and the future anticipated demand associated with these contracts is approximately 80 MGD as was shown in Table 1.  Requests for additional water supplies by current and new customers total approximately 57 MGD, and the future 2050 demand associated with these requests is approximately 46 MGD (as calculated from Table 1, by summing the second and third rows).  Thus if contracts were executed for all known requests, the total contracted amount would be approximately 150 MGD (93 + 57), and the year 2050 demand would be approximately 126 MGD (80 + 46).  The difference between year 2050 demand and contracts plus requests is 24 MGD (13 + 11).  Additional demand estimated during Regional Planning is approximately 41 MGD in 2050. 

 

2.2    Existing SRA Supplies

 

For the purposes of this study, the Upper Basin has been defined as that portion of the Sabine River Basin upstream of the headwaters of Toledo Bend Reservoir.  The only existing SRA water supply sources in the Upper Basin are Lake Tawakoni and Lake Fork.  The authorized diversion amount and the year 2000 and year 2050 estimated yields are shown in Tables 3 and 4 under various conditions.

 

Table 3.  Firm Yield of Lake Tawakoni and Lake Fork (acre-feet per year)

Model Criteria

Total Yield

SRA Portion of Yield

Operations

Return Flows 1

ACE 2

Tawakoni

Fork

Tawakoni

Fork

Total

Permitted

-

-

238,100

188,660

 47,600

56,800

104,400

 

 

 

 

 

 

 

 

Firm Yield

Yes

Original

238,100

177,400

47,600

53,410

101,010

Firm Yield

Yes

2000

238,100

171,900

47,500

51,750

99,350

Firm Yield

Yes

2050

229,000

158,500

45,780

47,720

93,500

Firm Yield

No

Original

235,300

176,300

47,040

53,080

100,120

Firm Yield

No

2000

227,000

170,900

45,380

51,450

96,830

Firm Yield

No

2050

219,000

158,000

43,780

47,570

91,350

1.  Return Flows, option “Yes” represents anticipated return flows as determined in the WAM.  Option “No” represents no return flows as used by the TCEQ for permitting of perpetual water rights.

2.  ACE (Area-Capacity-Elevation) represents the reservoir sedimentation condition used for the analysis, i.e. 2050 represents that an estimated year 2050 sedimentation condition was used in determining firm yields.


Figure 1

 

Figure 1.  SRA Upper Basin Supply and Demand
Table 4.  Firm Yield of Lake Tawakoni and Lake Fork (MGD)

Model Criteria

Total Yield

SRA Portion of Yield

Operations

Return Flows 1

ACE 2

Tawakoni

Fork

Tawakoni

Fork

Total

Permitted

-

-

212.6

168.4

 42.5

50.7

93.2

 

 

 

 

 

 

 

 

Firm Yield

Yes

Original

212.6

158.4

42.5

47.7

90.2

Firm Yield

Yes

2000

212.6

153.5

42.5

46.2

88.7

Firm Yield

Yes

2050

204.5

141.5

40.9

42.6

83.5

Firm Yield

No

Original

210.1

157.4

42.0

47.4

89.4

Firm Yield

No

2000

202.7

152.6

40.5

45.9

86.5

Firm Yield

No

2050

195.5

141.1

39.1

42.5

81.6

1.  Return Flows, option “Yes” represents anticipated return flows as determined in the WAM.  Option “No” represents no return flows as used by the TCEQ for permitting of perpetual water rights.

2.  ACE (Area-Capacity-Elevation) represents the reservoir sedimentation condition used for the analysis, i.e. 2050 represents that an estimated year 2050 sedimentation condition was used in determining firm yields.

 

The SRA portion of supply from these reservoirs has been fully allocated.  However, the current level of use by these customers is on the order of 25 percent of the allocated amount.  Thus from a short-term perspective, there is additional water that could be used on an interim basis from these reservoirs.    In order to use this additional water on an interim basis, the SRA must have a long-term supply mechanism that can be used to ultimately guarantee meeting all demands associated with existing contracts plus any additional contracts which the SRA might provide. 

 

The future supply associated with Lake Fork and Lake Tawakoni is expected to decrease due to sedimentation which occurs in the reservoirs.  Tables 3 and 4 reflect the reduction in yield over time due to projected sedimentation rates from the Water Availability Model (WAM) of the Sabine River Basin.  The sedimentation rate for Lake Fork from that study was based on a comparison of reservoir area-capacity from the original condition to a resurvey done in 2001.  Based on this comparison, the Lake Fork sedimentation rate was more than two times the sedimentation rate for Lake Tawakoni and significantly higher than previous estimates.  While this high calculated sedimentation rate does not impact the year 2000 yield, it does reduce the year 2050 yield.  If future resurveys of Lake Fork demonstrate that the sedimentation rate is in fact more similar to Lake Tawakoni, the SRA portion of Lake Fork year 2050 yield would increase by approximately 2 MGD.

 

2.3    Future System Yield

 

A system operations permit between Lake Tawakoni, Lake Fork and Toledo Bend Reservoir could theoretically be developed which allowed diversions of Toledo Bend inflows to be made in the Longview / Kilgore / Henderson area and would create some additional supply in the Upper Basin.  This additional supply would potentially offset the reduction in supply from Lake Tawakoni and Lake Fork due to sedimentation.  Tables 5 and 6 summarize the Upper Basin supply which would be available under the following operation scenarios:

 

 

The SRA portion of the yield of the various scenarios is based upon the following:

 

 

Tables 5 and 6 indicate the potential for a SRA system yield that is slightly higher than the currently permitted supply from Lake Fork and Lake Tawakoni.  This will be discussed in additional detail in the following section.  The diversions at SR-LV represent the diversions available from the Sabine River at the Longview / Kilgore / Henderson area.  This portion of the system yield would not be available to meet demands in the Lake Tawakoni and Lake Fork area.

 

Table 5.  SRA Upper Basin Yield Under Various Scenarios (acre-feet per year)

Model Criteria

Total Diversions or Releases by Location

SRA Diversions or Releases by Location

Reservoir Operation

Return Flows

ACE

Tawakoni

Fork

SR-LV *

Total

Tawakoni

Fork

SR-LV *

Total

Permitted

-

-

238,100

188,660

0

426,760

47,620

56,800

 

104,420

 

 

 

 

 

 

 

 

 

 

 

Firm Yield

Yes

Original

238,100

177,400

0

415,500

47,620

53,410

0

101,030

Firm Yield

Yes

2000

238,100

171,900

0

410,000

47,620

51,754

0

99,374

Firm Yield

Yes

2050

229,000

158,500

0

387,500

45,800

47,720

0

93,520

Firm Yield

No

Original

235,300

176,300

0

411,600

47,060

53,079

0

100,139

Firm Yield

No

2000

227,000

170,900

0

397,900

45,400

51,453

0

96,853

Firm Yield

No

2050

219,000

158,000

0

377,000

43,800

47,569

0

91,369

 

 

 

 

 

 

 

 

 

 

 

FY Plus

Yes

Original

238,100

177,400

19,277

434,777

47,620

53,410

19,277

120,307

FY Plus

Yes

2000

238,100

171,900

19,093

429,093

47,620

51,754

19,093

118,467

FY Plus

Yes

2050

229,000

158,500

18,070

405,570

45,800

47,720

18,070

111,590

FY Plus

No

Original

235,300

176,300

15,332

426,932

47,060

53,079

15,332

115,471

FY Plus

No

2000

227,000

170,900

15,332

413,232

45,400

51,453

15,332

112,185

FY Plus

No

2050

219,000

158,000

15,332

392,332

43,800

47,569

15,332

106,701

 

 

 

 

 

 

 

 

 

 

 

System

Yes

Original

238,100

161,660

57,000

456,760

47,620

37,670

57,000

142,290

System

Yes

2000

235,100

150,160

57,000

442,260

44,620

30,014

57,000

131,634

System

Yes

2050

226,600

134,660

47,000

408,260

43,400

23,880

47,000

114,280

System

No

Original

229,600

151,160

57,000

437,760

41,360

27,939

57,000

126,299

System

No

2000

224,000

148,660

47,000

419,660

42,400

29,213

47,000

118,613

System

No

2050

215,000

132,660

47,000

394,660

39,800

22,229

47,000

109,029

* SR-LV represents diversions available at the Sabine River above the Longview Streamflow Gage.  For System Operations, these diversions are backed by storage in Lake Fork and Lake Tawakoni.

 

Table 6.  SRA Upper Basin Yield Under Various Scenarios (MGD)

Model Criteria

Total Diversions or Releases by Location

SRA Diversions or Releases by Location

Reservoir Operation

Return Flows

ACE

Tawakoni

Fork

SR-LV *

Total

Tawakoni

Fork

SR-LV *

Total

Permitted

-

-

212.6

168.4

0.0

381.0

42.5

50.7

0.0

93.2

 

 

 

 

 

 

 

 

 

 

 

Firm Yield

Yes

Original

212.6

158.4

0.0

371.0

42.5

47.7

0.0

90.2

Firm Yield

Yes

2000

212.6

153.5

0.0

366.1

42.5

46.2

0.0

88.7

Firm Yield

Yes

2050

204.5

141.5

0.0

346.0

40.9

42.6

0.0

83.5

Firm Yield

No

Original

210.1

157.4

0.0

367.5

42.0

47.4

0.0

89.4

Firm Yield

No

2000

202.7

152.6

0.0

355.3

40.5

45.9

0.0

86.5

Firm Yield

No

2050

195.5

141.1

0.0

336.6

39.1

42.5

0.0

81.6

 

 

 

 

 

 

 

 

 

 

 

FY Plus

Yes

Original

212.6

158.4

17.2

388.2

42.5

47.7

17.2

107.4

FY Plus

Yes

2000

212.6

153.5

17.0

383.1

42.5

46.2

17.0

105.8

FY Plus

Yes

2050

204.5

141.5

16.1

362.1

40.9

42.6

16.1

99.6

FY Plus

No

Original

210.1

157.4

13.7

381.2

42.0

47.4

13.7

103.1

FY Plus

No

2000

202.7

152.6

13.7

369.0

40.5

45.9

13.7

100.2

FY Plus

No

2050

195.5

141.1

13.7

350.3

39.1

42.5

13.7

95.3

 

 

 

 

 

 

 

 

 

 

 

System

Yes

Original

212.6

144.3

50.9

407.8

42.5

33.6

50.9

127.0

System

Yes

2000

209.9

134.1

50.9

394.9

39.8

26.8

50.9

117.5

System

Yes

2050

202.3

120.2

42.0

364.5

38.8

21.3

42.0

102.0

System

No

Original

205.0

135.0

50.9

390.9

36.9

24.9

50.9

112.8

System

No

2000

200.0

132.7

42.0

374.7

37.9

26.1

42.0

105.9

System

No

2050

192.0

118.4

42.0

352.4

35.5

19.8

42.0

97.3

* SR-LV represents diversions available at the Sabine River above the Longview Streamflow Gage.  For System Operations, these diversions are backed by storage in Lake Fork and Lake Tawakoni.

 

For the purpose of evaluating long-term supply alternatives, the existing SRA Upper Basin supply was assumed to be the Firm Yield of Lake Tawakoni and Lake Fork with return flows.  If a system permit were to be obtained, the assumption of existing supply would be the System Yield with “no” return flows.  (The reason to include return flows in the Firm Yield and not in the System Yield is due to TCEQ permitting policies.  For planning purposes, “expected” return flows can be considered; however, when obtaining a perpetual water right, the TCEQ considers the “no” return flow scenario.  For the Firm Yield, the permits have already been granted, and because the future yields, even with return flows, are less than the permit, the “expected” return flow scenario can be used.  However, for the System Yield, new or amended permits would be required, and the TCEQ would base any system yield upon a “no” return flow scenario.)

 

One issue related to the possible system operations scenarios which must be evaluated in more detail is the impact that the resulting modifications to reservoir operations would have on lake levels at all of the reservoirs.  Preliminary analysis of this issue has been conducted for this study and it generally shows the impacts to be acceptable.  The overall impact on lake levels as a result of system operations is an increase in Lake Fork approximately 50 percent of the time and a decrease in Lake Tawakoni approximately 20 percent of the time.  Figures 2 and 3 show a comparison of the water levels between the various operational scenarios under the year 2050 reservoir conditions with no return flows.  The memorandum in Appendix B includes additional figures showing the impact


Figure 2

 

Figure 2.  Lake Fork Reservoir Storage Under Various Operations
Figure 3

 

Figure 3.  Lake Tawakoni Reservoir Storage Under Various Operations
on Lake Fork, Lake Tawakoni and Toledo Bend Reservoir for all the reservoir sedimentation and return flow combinations.

 

2.4    Summary of Additional Water Supply Needs

 

For the purpose of long-term supply planning, the existing SRA Upper Basin supply of available surface water can be estimated as the SRA portions of the firm yields of Lake Tawakoni and Lake Fork.  Under year 2050 conditions with return flows, this supply totals 83.5 MGD.  Development of a system permit could increase the SRA Upper Basin total available supply to 97.3 MGD (year 2050 conditions with no return flows).  Under system operations, the total SRA supply available at Lake Tawakoni and Lake Fork in 2050 would be 55.3 MGD, which is insufficient to satisfy the year 2050 SRA demand associated with existing contracts and requests for additional supplies in the Lake Tawakoni and Lake Fork area of 70 MGD.  However, a system permit could allow SRA to sell an additional 4 MGD of supply (above the currently contracted 93.2 MGD) if no more than 55.3 MGD of demands occur in the Lake Tawakoni and Lake Fork area (which is the case, as only 41.7 MGD of the currently contracted supply is for use in the Lake Tawakoni and Lake Fork area).  This 4 MGD of additional supply could be sold without any additional supply sources being planned.  If the SRA were to obtain a system yield permit based on year 2000 area-capacity, the additional permitted supply would be approximately 12 MGD; however, that additional supply would diminish to 4 MGD in 2050 due to reservoir sedimentation.

 

For long-term planning, two sets of demands were assumed:  one which meets existing contracts and requests for additional water, and a second demand set which adds additional projected demands developed during the Regional Planning process.  These additional demands total approximately 41 MGD in 2050.  Table 7 summarizes the total demands for these scenarios and the amount of additional long-term supply required by decade.  Due to the significant amount of demands from Regional Planning that are not represented in existing requests, a flexible plan is recommended such that implementation phases could be pushed forward or delayed as Regional Planning demands materialize or do not materialize.

 

Table 7.  Additional Supplies Needed for Demand Scenarios (MGD)

 

2000

2005

2010

2020

2030

2040

2050

Existing Supply in Lake Tawakoni & Lake Fork

88.7

88.2

87.7

86.6

85.6

84.5

83.5

Demand Scenario No. 1

 

 

 

 

 

 

 

Demands associated with Contracts & Requests

35.0

73.4

85.0

102.7

113.0

118.6

126.0

Additional Supply Needed

0.0

0.0

0.0

16.0

27.5

34.1

42.5

Demand Scenario No. 2

 

 

 

 

 

 

 

Demands associated with Contracts, Requests and Regional Planning

35.0

80.4

93.8

128.3

149.0

157.1

166.9

Additional Supply Needed

0.0

0.0

6.1

41.7

63.4

72.5

83.4

 

Some of the existing contract holders do not estimate that their demands will reach their full contracted amounts by 2050.  The largest amounts from such estimates are from the City of Commerce and the City of Terrell.  The City of Commerce has a contract for 7.5 MGD and only has a projected demand of 3.5 MGD in 2050.  The City of Terrell has a contract for 9 MGD and only has a projected demand of 1.6 MGD in 2050.  At this time neither entity has expressed a desire to relinquish the apparent excess supply such that SRA could sell it to a new customer.  It should be noted that the projected demand used to develop long-term supply alternatives presented in the following section are based on customers using water at the demand levels estimated for 2050, and not at the full contracted amount.  As stated previously, the difference between contracted amounts and year 2050 demands is approximately 24 MGD.  Thus additional supplies would be necessary after 2050 as demands continue to grow to reach the contracted amounts.

 


3.0    Alternatives to Meet Identified Shortages

 

The following alternatives were identified for evaluation as a part of a short and long-term water supply plan.

 

Prairie Creek Reservoir

Local Groundwater Supplies

Toledo Bend Pipeline

            To Lake Fork

            To Longview / Kilgore Area

Temporary Dallas Water Supply Contract

Temporary Lake Cherokee Water Supply Contract

Dallas In-Basin Supply from Lake Fork

 

3.1    Prairie Creek Reservoir

 

Prairie Creek Reservoir was evaluated as a potential long-term supply source in the 1999 Comprehensive Sabine Watershed Management Plan.  This project is proposed on a site with relatively few developmental concerns.  However, the reservoir as currently proposed does not have the potential to meet all of the projected future demands in the Upper Basin.  The 1985 Master Plan Update included an estimate for the yield of the reservoir of 19,700 ac-ft/yr.  If the reservoir were operated with high flow scalping diversions from the Sabine River, the yield could be increased to 29,685 ac-ft/yr.  The total construction costs and the unit costs of water delivered and sold are shown in Table 8.  Detailed cost data for Prairie Creek Reservoir is provided in Appendix C.

 

Table 8.  Prairie Creek Reservoir Cost Summary

 

Total Construction Cost

50 Year Life Cycle Analysis

100 Year Life Cycle Analysis

Average Deliveries (MGD)

Cost per 1000 gallons delivered

Average Water Sold (MGD)

Cost per 1000 gallons sold

Average Deliveries (MGD)

Cost per 1000 gallons delivered

Average Water Sold (MGD)

Cost per 1000 gallons sold

Prairie Creek Reservoir

$63,787,000

11.2

$ 0.71

17.6

$ 0.45

14.4

$ 0.35

17.6

$ 0.28

Reservoir With Scalping

$84,204,000

15.6

$ 0.69

26.5

$ 0.41

21.0

$ 0.34

26.5

$ 0.27

 

 

3.2    Pipeline From Toledo Bend Reservoir

 

While the Upper Basin has projected water supply shortages in the next 50 years, the Lower Basin is projected to have an abundant supply significantly beyond the next 50 years.  Thus one alternative is to convey Toledo Bend water to the Upper Basin.  A pipeline from Toledo Bend Reservoir to the Longview / Kilgore / Henderson area (LKH area) could be sized to meet a variety of demands.  By satisfying demands in the LKH area with Toledo Bend water, Lake Fork water could be reallocated to meet demands in the Lake Tawakoni area.  Thus a pipeline would not be required from Toledo Bend for the entire distance to Lake Fork or Lake Tawakoni.  Instead, a pipeline from Toledo Bend to the LKH area could operate in combination with a pipeline from Lake Fork to Lake Tawakoni and thus create a lower capital cost than a pipeline from Toledo Bend to Lake Fork or Lake Tawakoni. 

 

In developing pipeline alternatives, an important element was the ability to phase construction and develop a plan that is flexible enough to meet changing demands through 2050.  A total of five pipeline alternatives were evaluated to meet the following demands for additional supply in order of increasing magnitude of supply:

 

TB 1.       Existing contracts plus requests for additional supply, assuming 10 MGD can be obtained from the Dallas in-basin Lake Fork allocation, resulting in year 2050 additional required supply of 32 MGD.

TB 2.       Existing contracts plus requests for additional supply, resulting in year 2050 additional required supply of 42 MGD.

TB 3.       Existing contracts, requests for additional supply and projected Regional Planning demands assuming 10 MGD can be obtained from the Dallas in-basin Lake Fork allocation, resulting in year 2050 additional required supply of 73 MGD.

TB 4.       Existing contracts, requests for additional supply and projected Regional Planning demands, resulting in year 2050 additional required supply of 83 MGD.

TB 5.       Entire LKH contract demands, requests for additional supply, and projected Regional Planning demands, resulting in year 2050 additional required supply of 97 MGD.

 

Figure 4 shows the general pipeline routing for all five alternatives.  For Alternatives 1 through 4, a common pipeline size of 60-inch diameter was used for the segments from Toledo Bend to the City of Henderson.  The variation in these alternatives is the construction dates for the various segments as well as the need for a parallel pipeline along a portion of the route in Alternatives 3 and 4.  The demands associated with Alternative 5 are such that the ultimate requirement is parallel 66-inch diameter pipelines.  If the initial pipeline from Toledo Bend was 60-inch diameter, in order to meet the Alternative 5 demands, the parallel pipeline would need to be 72-inch diameter and would need to be implemented sooner.

 

Table 9 shows the pipeline sizes and implementation dates for the five alternatives.  Table 10 summarizes the total construction cost and cost per unit of water sold and cost per unit of water delivered for each alternative.  Additional details on each of the alternatives including construction costs are presented in Appendix D.

 


Figure 4

 

Figure 4.  General Pipeline Routing
Table 9.  Toledo Bend Pipeline Alternatives

Alternative

Toledo Bend to Martin Lake

(50 miles)

Martin Lake to Henderson

(10 miles)

Henderson to Kilgore

(20 miles)

Kilgore to Prairie Creek

(8 miles)

Parallel Pipeline to Booster P.S.

 

Size

Date

Size

Date

Size

Date

Size

Date

Size

Date

TB 1

60

2018

60

2024

54

2030

48

2047

n/a

n/a

TB 2

60

2012

60

2018

54

2020

48

2033

n/a

n/a

TB 3

60

2012

60

2018

54

2019

48

2026

60

2035

TB 4

60

2007

60

2012

54

2017

48

2019

60

2028

TB 5

66

2005

66

2005

60

2005

60

2005

66

2018

Total pipeline distance from Toledo Bend Reservoir to Prairie Creek is approximately 88 miles.

 

Table 10.  Toledo Bend Pipeline Alternatives Cost Summary

Alternative

Total Construction Cost

50 Year Life Cycle Analysis

100 Year Life Cycle Analysis

Average Deliveries (MGD)

Cost per 1000 gallons delivered

Average Water Sold (MGD)

Cost per 1000 gallons sold

Average Deliveries (MGD)

Cost per 1000 gallons delivered

Average Water Sold (MGD)

Cost per 1000 gallons sold

TB 1

$144,226,000

12.3

$ 1.33

30.0

$ 0.54

22.3

$ 0.61

30.0

$ 0.45

TB 2

$145,912,000

18.9

$ 1.05

40.0

$ 0.50

30.6

$ 0.51

40.0

$ 0.39

TB 3

$217,782,000

34.8

$ 0.87

60.0

$ 0.50

53.9

$ 0.50

65.0

$ 0.42

TB 4

$217,781,000

42.7

$ 0.80

70.0

$ 0.49

62.9

$ 0.48

75.0

$ 0.41

TB 5

$283,477,000

70.5

$ 0.71

70.0

$ 0.71

83.8

$ 0.47

75.0

$ 0.49

 

 

3.3    Local Groundwater

 

Groundwater is available from the Queen City (QC) and Carrizo-Wilcox (CW) Aquifers in the Upper Basin upstream of the Longview / Kilgore/ Henderson (LKH) area.  One option for supplying the LKH area would be to develop well fields from these aquifers and use the bed and banks of the Sabine River and its tributaries to transport the water to existing diversion points in the LKH area.  This option would then allow the reallocation of existing supplies in Lakes Fork and Tawakoni to meet demands in the Fork and Tawakoni area instead of being released to serve the LKH area.  Approximately 45 MGD is identified as potentially available (net) from this source of supply.  The proposed well fields are detailed in Table 11.

 

Table 11.  Proposed Groundwater Wellfields

Field (County)

Gregg

Harrison

Smith

Upshur

Wood

Total

Number of Wells

18

17

32

15

32

114

Aquifer

CW, QC

CW, QC

CW, QC

QC

QC

CW, QC

Avg. Depth (ft)

800

450

700

550

550

610 (avg.)

Avg. Production (gpm)

375

250

325

275

275

300 (avg)

Field Production (MGD)

9.7

6.1

15.0

5.9

12.7

49.4

Channel Loss (10%)

-1.0

-0.6

-1.5

-0.6

-1.3

-5.0

Net Production (MGD)

8.7

5.5

13.5

5.3

11.4

44.4

 

These proposed well fields use only 20.9 % of the estimated 268,400 acre-feet per year (240 MGD) of unused groundwater identified in the Regional Water Plans within the Sabine Basin portion of these counties.  However, this availability should be verified by modeling the proposed well fields using the final version of the Carrizo-Wilcox Groundwater Availability Model.  Additional considerations which may limit the ability to use groundwater as a significant source of supply include:  water quality issues related to permitting groundwater that enters surface water streams due to potentially high TDS and metals contents; and political issues such as formation of groundwater conservation districts and other opposition from local government and private property owners. 

 

The relatively short distances between the point of discharge into the Sabine River and the diversion points should minimize the channel losses (estimated here at 10%).  Use of bed and banks to transport the water will improve the water quality by blending it with existing surface water in these streams.  Additionally, transporting this water using bed and banks in lieu of constructing a pipeline reduces the unit cost of development of this source of supply to an estimated $0.37 per 1000 gallons at the diversion point.  Appendix E provides more detailed discussion of the groundwater alternative.

 

3.4    Temporary Use of Lake Cherokee Water Supply

 

Lake Cherokee is owned and operated by the Cherokee Water Company.  The currently contracted amount of 18,000 acre-feet per year (16.1 MGD) is much less than the firm yield of 36,500 ac-ft/yr (32.6 MGD).  The “current conditions” scenario from the WAM included a diversion of 17,423 ac-ft/yr (15.6 MGD).  The preferred operation of the Cherokee Water Company is to limit drawdown in Lake Cherokee to 4.5 feet.  This limitation on drawdown is necessary to maintain a sufficient level for the operation of Southwest Electric Power Company’s power plant on Lake Cherokee.  The variation in reservoir level in the WAM current conditions scenario was approximately six feet.  Thus, within the current operation, no additional short-term supply is available from Lake Cherokee.

 

3.5    Temporary Use of Dallas Lake Fork Supply

 

A temporary contract with the City of Dallas may be possible which would allow SRA to use water from the 120,000 acre-feet per year (107 MGD) allocation of Lake Fork that is part of the City of Dallas long-term water supply plan during those interim years before Dallas demands require the supply.  The Dallas need for additional supplies beyond what is currently connected to its system occurs by 2010.  The most likely additional supplies which Dallas has available to meet these needs are Lake Fork and Lake Palestine.  Currently pipelines are being designed and constructed which would allow the City of Dallas to begin diversions from Lake Fork in the near future.  Table 12 shows the expected utilization of Lake Fork supplies assuming that Dallas uses its entire Lake Fork supply before connecting Lake Palestine.  Under this assumption the Dallas Lake Fork supply will be fully used by Dallas in 2018.  Prior to 2018, a portion of that supply could be reallocated to SRA in order to satisfy Upper Basin needs during that interim period.  Table 11 also shows the additional supplies needed by SRA to satisfy demands in the Upper Basin.  For the SRA demand scenario that includes Regional Planning demands, a temporary agreement with the City of Dallas for unused Lake Fork water could satisfy SRA Upper Basin demands through 2014.  In 2015, the total need of Dallas and SRA of 98.7 MGD exceeds the estimated pro-rated yield allocated to the City of Dallas of 94.5 MGD.  (This alternative, in combination with an agreement for the City of Dallas in-basin water, described below, would add an additional year before a long-term alternative would be required.)  While this alternative would not provide a long-term supply, it does provide the potential to delay construction costs associated with any of the long-term supply alternatives.

 

Table 12.  Potential Use of Dallas Lake Fork Supplies (MGD)

Year

Pro-rated Yield

Use by Dallas Water Utilities

SRA Additional Supply Needed for

Dallas plus SRA Contracts & Requests

Dallas plus SRA Contracts & Requests & Regional Planning

Contracts & Requests

Contracts, Requests & Regional Planning

2000

97.6

0.0

0.0

0.0

0.0

0.0

2001

97.5

0.0

0.0

0.0

0.0

0.0

2002

97.3

0.0

0.0

0.0

0.0

0.0

2003

97.1

0.0

0.0

0.0

0.0

0.0

2004

97.0

0.0

0.0

0.0

0.0

0.0

2005

96.8

0.0

0.0

0.0

0.0

0.0

2006

96.6

20.3

0.0

0.0

20.3

20.3

2007

96.4

28.6

0.0

0.0

28.6

28.6

2008

96.2

36.9

0.0

0.5

36.9

37.4

2009

96.0

45.1

0.0

3.3

45.1

48.5

2010

95.8

53.4

0.0

6.1

53.4

59.5

2011

95.5

59.7

0.0

7.6

59.7

67.4

2012

95.3

66.0

0.0

9.1

66.0

75.2

2013

95.0

72.4

0.7

10.7

73.1

83.0

2014

94.7

78.7

1.9

12.2

80.6

90.9

2015

94.5

85.0

3.0

13.7

88.0

98.7

2016

94.1

91.4

4.1

15.2

95.5

106.5

2017

93.8

97.7

5.3

16.7

103.0

114.4

2018

93.5

104.0

6.4

18.2

110.5

122.2

2019

93.1

110.4

7.6

19.7

117.9

130.1

2020

92.7

116.7

16.0

41.7

132.7

158.4

 

 

3.6    Use of Dallas Lake Fork In-Basin Supply

 

In addition to the 120,000 ac-ft/yr currently contracted to the City of Dallas, the City of Dallas has 11,860 ac-ft/yr (10.6 MGD) of Lake Fork supply that is not authorized for interbasin transfer.  Under a new contract agreement with Dallas, this supply could potentially be used by the SRA to meet a portion of its future demand.    The contractual issues associated with this supply alternative should be further explored with the City of Dallas.

 

3.7    Pipeline from Lake Fork to Lake Tawakoni

 

Although a pipeline from Lake Fork to Lake Tawakoni will not introduce additional supply to the Upper Basin, the ability to convey water between these two reservoirs will be required in order to meet the Upper Basin demands.  By year 2015, the projected demand in the Lake Tawakoni area is expected to exceed the SRA portion of the Lake Tawakoni firm yield.  By year 2050, the average demand in the Lake Tawakoni area is expected to exceed the firm yield of Lake Tawakoni by approximately 25 MGD. 

 

The pipeline from Lake Fork to Lake Tawakoni is not an alternative to be compared to the others, but is instead required regardless of which alternative(s) is (are) selected.  While capacity may be available in the pipeline currently being designed and constructed for the City of Dallas, costs have been developed for a new 42-inch diameter pipeline which would be dedicated to the SRA demands only in order to provide a “worst case” alternative in terms of estimated costs.  This pipeline would be sufficient to meet the year 2050 average demand of 25 MGD at Lake Tawakoni that must be met by Lake Fork supplies.  Table 13 shows the total construction costs and unit costs to transport water sold from Lake Fork but delivered from Lake Tawakoni.

 

Table 13.  Lake Fork to Lake Tawakoni Pipeline Summary

Total Construction Cost

50 Year Life Cycle Analysis

100 Year Life Cycle Analysis

Average Deliveries (MGD)

Cost per 1000 gallons delivered

Average Water Sold (MGD)

Cost per 1000 gallons sold

Average Deliveries (MGD)

Cost per 1000 gallons delivered

Average Water Sold (MGD)

Cost per 1000 gallons sold

$30,979,000

9.7

$ 0.48

25.0

$ 0.18

16.8

$ 0.22

25

$ 0.15

 

 

3.8    Additional Water Delivery Costs

 

In the current situation, each of the five existing customers in the LKH area receives SRA water from the Sabine River via facilities operated by the individual customers.  The only exception is Texas Utilities, which does not currently have pump station and pipeline facilities to deliver its existing contracted water from the Sabine River to Martin Lake.  In order to satisfy year 2050 demands, additional facilities will be required for the Cities of Kilgore and Henderson.  Since there are no existing facilities associated with the projected demands such as Gregg County Manufacturing or Rusk County Steam Electric, once those demands materialize, new facilities would be required to transport the water from any of the identified potential sources.

 

With the exception of the Toledo Bend Pipeline alternative, each of the long-term supply alternatives (Groundwater, Prairie Creek Reservoir, Contractual Transfers with the City of Dallas) provides water to SRA customers at the Sabine River and must undergo additional conveyance to reach the customer’s final point of use.  The Toledo Bend Pipeline alternative would deliver water to Texas Utilities at the headwaters of Martin Lake and would also deliver water to a point near the water treatment plants of the Cities of Kilgore and Henderson, thus no additional conveyance would be required under this alternative.  Regional Planning demands such as Rusk County Steam Electric and Panola County Mining would take deliveries off the pipeline as well.  The additional customers such as Gregg County Manufacturing, the City of Longview, and Eastman Chemical Company could still receive their deliveries via the Sabine River, similar to the other alternatives. 

 

The Toledo Bend Pipeline alternative thus provides additional benefit to those customers along the pipeline route in terms of reducing the need and cost for additional transmission facilities which would require operation by the customer.  In order to allow for better comparison among the various alternatives and take into account the variation in additional customer facilities which would be required, costs have been calculated for a pump station and pipeline from the Sabine River to Martin Lake, and for a pump station and pipeline from the Sabine River to the Cities of Kilgore and Henderson.  These costs are shown in Table 14 and are based upon the assumption of constructing a parallel pipeline to the existing Kilgore and Henderson pipeline since it has insufficient capacity for year 2050 demand.

 

Table 14.  Additional Customer Facilities

Sabine River to

Total Construction Cost

50 Year Life Cycle Analysis

100 Year Life Cycle Analysis

Average Deliveries (MGD)

Cost per 1000 gallons delivered

Average Water Sold (MGD)

Cost per 1000 gallons sold

Average Deliveries (MGD)

Cost per 1000 gallons delivered

Average Water Sold (MGD)

Cost per 1000 gallons sold

Kilgore & Henderson

$ 23,523,000

4.3

$ 0.87

9.5

$ 0.39

5.6

$ 0.46

9.5

$ 0.27

Martin Lake

$ 11,687,000

10.7

$ 0.22

10.7

$ 0.22

10.7

$ 0.16

10.7

$ 0.16

 


4.0    Summary and Conclusions

 

The existing SRA water supply available in the Upper Basin includes Lake Tawakoni and Lake Fork.  The yield from these reservoirs is expected to decrease in the future due to sedimentation.  The Upper Basin is expected to have demands for water from SRA which exceed the current SRA supply within the next 10 to 20 years.  These demands take into account water conservation measures as a means to reduce the need for new supplies.  Two distinct future need scenarios have been evaluated: 1) “Existing Contracts and Requests”, and 2) “Existing Contracts, Requests and Regional Planning”.  The need for additional supplies was discussed in Section 2.4 and is summarized in Table 15.

 

Table 15.  Summary of Additional Supply Needed (MGD)

 

2000

2005

2010

2020

2030

2040

2050

1)  Additional Supply Needed to Meet Contracts & Requests

0.0

0.0

0.0

16.0

27.5

34.1

42.5

2)  Additional Supply Needed to Meet Contracts, Requests and Regional Planning

0.0

0.0

6.1

41.7

63.4

72.5

83.4

 

Several short and long-term alternatives were evaluated as part of the overall water supply plan.  A temporary contract to use water from Lake Cherokee is not feasible due to operating constraints of the lake whereby the water level fluctuations must be minimized.  A temporary contract with Dallas to use Lake Fork water that is not needed by Dallas could satisfy SRA demands for additional water until 2014 (for demand scenario No. 2) or 2015 (for demand scenario No. 1).  While this option would not meet long-term needs, it would delay implementation of other strategies, thus deferring some capital costs.  In addition to the Lake Fork supply which will ultimately be used by Dallas, the Dallas “in-basin” supply from Lake Fork could supply up to 10.6 MGD to satisfy a portion of the SRA demands in the Upper Basin. 

 

A system yield permit that includes Lake Tawakoni, Lake Fork and Toledo Bend Reservoir with upstream diversions in the Longview / Kilgore area could provide additional supply to the SRA.  The additional supply is approximately 4 MGD under projected (conservative) year 2050 reservoir sedimentation conditions, and 12 MGD under year 2000 sedimentation conditions.

 

In order to meet the year 2050 demands, Prairie Creek Reservoir, groundwater development and/or a pipeline from Toledo Bend Reservoir will be needed.  Table 16 presents the expected supplies available from these alternatives.

 

Table 16.  Comparison of Long-Term Supply Alternatives (MGD)

Alternative

Supply Available

Total Construction Cost

50 Year Life Cycle Analysis

100 Year Life Cycle Analysis

Average Deliveries (MGD)

Cost per 1000 gallons delivered

Average Water Sold (MGD)

Cost per 1000 gallons sold

Average Deliveries (MGD)

Cost per 1000 gallons delivered

Average Water Sold (MGD)

Cost per 1000 gallons sold

Prairie Creek Reservoir

17.6

$ 63,787,000

11.2

$ 0.71

17.6

$ 0.45

14.4

$ 0.35

17.6

$ 0.28

Reservoir With Scalping

26.5

$ 84,204,000

15.6

$ 0.69

26.5

$ 0.41

21.0

$ 0.34

26.5

$ 0.27

TB 1

32

$144,226,000

12.3

$ 1.33

30.0

$ 0.54

22.3

$ 0.61

30.0

$ 0.45

TB 2

42

$145,912,000

18.9

$ 1.05

40.0

$ 0.50

30.6

$ 0.51

40.0

$ 0.39

TB 3

73

$217,782,000

34.8

$ 0.87

60.0

$ 0.50

53.9

$ 0.50

65.0

$ 0.42

TB 4

83

$217,781,000

42.7

$ 0.80

70.0

$ 0.49

62.9

$ 0.48

75.0

$ 0.41

TB 5

97

$283,477,000

70.5

$ 0.71

70.0

$ 0.71

83.8

$ 0.47

75.0

$ 0.49

Ground water

45

$ 47,031,000

18.9

$ 0.37 *

 

 

 

 

 

 

TB # represents Toledo Bend Pipeline alternatives.

Groundwater unit pricing based on 30-year life cycle analysis.

*  Unit costs for Toledo Bend Alternatives do not include the cost of Toledo Bend raw water.

 

Of these alternatives, Prairie Creek Reservoir alone cannot meet either of the demand scenarios.  However, when operated with high flow scalping diversions, more than half of the need from demand scenario No. 1 can be met.  Prairie Creek Reservoir could also be used for terminal storage of water delivered via pipeline from Toledo Bend, thus reducing the peaking factor and therefore the capital costs associated with such a pipeline.  There are significant risks associated with implementation of the reservoir including: property owner resistance to land acquisition, permitting requirements related to impacts of the reservoir on instream flows and land features and environmental opposition.

 

The potential supply available from groundwater could meet a portion of the need associated with demand scenario No. 1 in those areas in close proximity to available groundwater.  If issues such as water quality or public opposition reduce the available groundwater, the unit costs are not expected to change, such that any quantity of groundwater may be effectively combined with other alternatives.  Risks associated with groundwater development include: water quality concerns, potential impact on other wells, possible public reaction to use of remote (rural) groundwater fields to serve urban growth, and permitting requirements.  These significant issues must be addressed before groundwater can be considered a viable option for meeting future demands.

 

The only alternative which alone can meet the needs associated with projected demand scenarios No. 1 and No. 2 is a pipeline from Toledo Bend to the Longview / Kilgore / Henderson area.  Of the long-term supply alternatives evaluated, this alternative has the most limited anticipated environmental impacts or regulatory requirements.  This alternative has also the flexibility to adjust construction dates of segments to meet a variety of potential demands.  This alternative is relatively expensive on a cost per 1000 gallons delivered.  If the current requests for additional water are converted into take-or-pay contracts, the cost per 1000 gallons sold would be significantly less.  Other potential customers of Toledo Bend water could be included in the pipeline alternatives in order to reduce the “unit price” to SRA by introducing greater economy of scale for the pipeline conveyance. 

 

Regardless of which identified short or long-term supply alternative is selected by SRA, there will remain a projected need to deliver water from Lake Fork to Lake Tawakoni by year 2015.  If the SRA does not obtain capacity in the pipeline currently being constructed by Dallas, a 42-inch diameter / 25 MGD pipeline dedicated to SRA needs could be constructed at an estimated cost of approximately $31,000,000, and a unit cost of approximately $0.18 per thousand gallons sold.

 

The recommended implementation activities and the potential amounts of additional long-term supply that could be made available are summarized below.

 

·        Initiate application with TCEQ for a system permit between Lake Fork, Lake Tawakoni and Toledo Bend Reservoir to allow upstream diversions from Toledo Bend Reservoir in the Longview / Kilgore / Henderson area.  (4 MGD of new supply.)

·        Pursue additional partnerships for use of Toledo Bend Reservoir supplies in order to increase the capacity of pipeline and pumping facilities and reduce the cost of the resulting water conveyance. (Up to 83 MGD of new supply.)

·        Continue negotiations with Dallas to allow SRA to use a portion of the capacity of the Dallas pipeline from Lake Fork to Lake Tawakoni.  If not successful, initiate detailed planning and begin right-of-way acquisition for a separate 42-inch diameter/ 25 MGD SRA pipeline.

Other alternatives to be considered if issues associated with them can be resolved include:

·        Continue negotiations with Dallas to allow SRA to acquire Dallas in-basin water.  (10.6 MGD of new supply.)

·        Retain the Prairie Creek Reservoir as a future element in the SRA’s Upper Basin Plan, but defer further investigations of this option pending development of further studies related to use of Toledo Bend Reservoir supplies (No new supply at this time but up to 26.5 MGD if re-initiated at a later date.)

·        Conduct feasibility studies for conjunctive use of groundwater in selected areas of the Upper Basin.  Evaluate impact on existing wells, water quality, and use of bed and banks to transfer supplies to demand areas.    (Up to 45 MGD of new supply.)

·        Obtain agreement for temporary use of Dallas Lake Fork supplies on an interim basis in order to delay construction costs associated with long-term alternatives.