Lake Ringgold Study

November 5, 2013

CITY OF WICHITA FALLSCOUNCIL MEETING

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

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

Recent Studies

• Region B Water Plan– Recommended Strategy

• Reservoir Site Assessment Study (2007)– Unique Reservoir Designation

• Expires in 2015, unless progress toward implementation

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

Location Map

Lake Ringgold

Area = 16,000 acreCapacity = 275,000 ac-ftLake Elevation = 844 ft

Henrietta

Lake Ringgold Comparison

• Lake ArrowheadElevation = 926 feet mslArea = 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 acre-

feet

• Lake RinggoldElevation = 844 feet mslArea = 16,000 acresCapacity = 275,000 acre-

feetYield = 27,800 ac-ft/year

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

Dam Site Layout

ConflictsOil/Gas pipelinesHenrietta’s pump stationHomes/structuresRoads

Property owned by Wichita Falls

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

Environmental Review

Wetlands – 910 acres

Streams – 873,300 feet

Open water – 120 acres

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

Archeological Potential

• Few cultural resource surveys

• Favorable archeological site conditions

• Tribal consultation is a possibility

• Will require on-site field survey

Project Costs

Land Purchase $ 38

Dam and Spillway $ 71.5

Conflicts $ 7.4

Permitting & Mitigation $ 73.5

Contingency (20%) $ 38

TOTAL $ 228.5

Millions

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

Summary - Unknowns

• Archeological potential– Not a fatal flaw

• Stream mitigation

• On-going drought