The document summarizes a study of Lake Ringgold, a proposed reservoir that would provide additional water supply for the city of Wichita Falls, Texas. Key points from the study include that the reservoir would have an area of 16,000 acres, capacity of 275,000 acre-feet, and yield of 27,800 acre-feet per year. The proposed dam design involves an earthen embankment with uncontrolled spillways. Environmental reviews found potential impacts to threatened species but overall few concerns. Estimated costs to develop the reservoir are $228.5 million. The study concludes Lake Ringgold is a viable project to maximize water resources, but some unknowns like archaeological impacts remain.

1. Lake Ringgold Study
CITY OF WICHITA FALLS
COUNCIL MEETING
November 5, 2013

2. Lake Ringgold History
• 1957 – Water Right, Wichita
County WCID #1
– Water Supply for Wichita Falls
• 1958 – FNI study for Tarrant
County District
– Excess water from Ringgold
• 1962 – Water right for Lake
Arrowhead

3. Lake Ringgold History
• 1978 – 1981, FNI conducted studies on
additional supply for Wichita Falls
• Lake Ringgold
– Re-evaluated for smaller project
– Estimated system gain with Ringgold
27,640 af/y
• City of Wichita Falls began purchasing
properties in reservoir site

4. Recent Studies
• Region B Water Plan
– Recommended Strategy
• Reservoir Site Assessment
Study (2007)
– Unique Reservoir Designation
• Expires in 2015, unless progress toward
implementation

5. Current Study
• Joint Study – Wichita Falls and TRWD
– TRWD interested as terminal storage for Oklahoma water
Scope of Work
• Hydraulics and Conceptual Dam Design
– New PMF methodology
– Spillway configuration options
• Environmental Review
– New regulations
• Update Cost Estimate

6. Location Map

7. Lake Ringgold
Area = 16,000 acre
Capacity = 275,000 ac-ft
Lake Elevation = 844 ft
Henrietta

8. Lake Ringgold Comparison
• Lake Arrowhead
Elevation = 926 feet msl
Area = 15,000 acres*
Capacity = 236,000 acre-feet*
Yield = 29,000 ac-ft/year
*2001 Volumetric Survey
• Original area = 16,200 acres
• Original capacity = 262,100 acrefeet
• Lake Ringgold
Elevation = 844 feet msl
Area = 16,000 acres
Capacity = 275,000 acre-feet
Yield = 27,800 ac-ft/year

9. Dam Configuration
• Earthen Embankment
– Elevation – 871.5 feet msl
– Maximum height – 81.5 feet
– Length – 8,585 feet
• Uncontrolled Principal Spillway
– Elevation – 844 feet msl
– Crest width – 350 feet
• Emergency Spillway
–
–
–
–
Earthen channel
Elevation – 856 feet msl
Crest width – 500 feet
Discharge to Red River

10. Dam Site Layout

11. Conflicts
Oil/Gas pipelines
Henrietta’s pump station
Homes/structures
Roads
Property
owned by
Wichita Falls

12. Project Yield
• Firm Yield - 27,800 ac-ft/yr
• Environmental Flows – small impact on yield
• Lowest inflows – past 10 years
– Similar to drought in late ‘70s – early ‘80s

13. Environmental Review
Wetlands – 910 acres
Streams – 873,300 feet
Open water – 120 acres

14. Threatened and Endangered
Species
• Two federally listed species
– Low to no potential impacts
• Nine State listed species
– Low to no potential impacts to
7 species
• Potential impacts to Texas
Kangaroo Rat and Texas
Horned Lizard
– Both State listed threatened

15. Archeological Potential
• Few cultural resource surveys
• Favorable archeological site
conditions
• Tribal consultation is a
possibility
• Will require on-site field
survey

16. Project Costs
Millions
Land Purchase
$ 38
Dam and Spillway
$ 71.5
Conflicts
$
Permitting & Mitigation
$ 73.5
Contingency (20%)
$ 38
TOTAL
$ 228.5
7.4

17. Summary
• Lake Ringgold is a viable project
• Maximizes water supply from Little Wichita watershed
– Utilizes unique reservoir site
– Last viable option for new supplies for Wichita Falls
• Site supports dam location
– Geology and topography
• Can likely be constructed with local materials
• Minimizes potential liability – uncontrolled spillways
• Few environmental concerns

18. Summary - Unknowns
• Archeological potential
– Not a fatal flaw
• Stream mitigation
• On-going drought