Surface Water Availability

Surface Water Considerations

Physical Availability

Safe Yield

Excess Surface Water

Allocation During Time of

Shortage

Fish and Wildlife Flows

USACE Projects

Interstate Compacts

Excess Surface Water25% of water available on an average, annual basis

above that required to meet existing/projected future needs , for non-riparian uses or interbasin transfer.

Existing/Projected Needs:1. Existing riparian rights2. Water needs of federal water projects3. Firm yield of reservoirs4. Maintenance of instream flows (Fish & Wildlife, WQ,

Navigation, and Aquifer Recharge), and5. Future needs in that basin

Excess Surface Water Determination1990 Plan calculated excess

water for 8 areas using 19 gages 2014 Update uses 51 gages to

calculate excess water in 9 major river basins and 32 sub-basins

Updated stream flow data and demands

No change assumed if demand decreased

Excess Water, by River Basin

River BasinExcess Water

(Million ac-ft/yr)White River (Cache)

1.7

Arkansas River 3.3Delta 1.6Ouachita River 1.0Red River 1.1

Excess Surface Water Availability Results1990 Statewide total excess surface water ~10.5 million ac-ftUpdated Statewide total ~8.74 million ac-ftDifferences result from updated demand projections, changes in

in-stream needs (e.g., White River minimum flows), and basin differences (e.g., 1990 East Arkansas methodology)

Represents annual average, but does not reflect seasonal variations

US Army Corps of Engineers (USACE) Projects

Arkansas Water Plan (AWP) references the annual summary of USACE projects

Current allocation status for each reservoir

Summary of general process required for reallocation

Interstate CompactsCompact delivery

requirements limit available surface water

Arkansas River Compact (AR and OK)

Red River Compact (OK, TX, AR and LA) – includes all areas south of the Arkansas River watershed

Fish and Wildlife Flows

Fish and Wildlife Flows Subgroup formedTechnical workshop – March 2013

Reviewed the Arkansas Method, Modified Tennant Method

Reviewed national and southeastern methods for estimating instream flows

Recommended path forward

RecommendationsUse the Arkansas Method for estimating fish and wildlife

flows and updating excess flow estimates for the 2014 Arkansas Water Plan

Determine flow-ecology relationships and develop an empirical, risk-based method for estimating flow-ecology (e.g., fishery) relationships, based on:MagnitudeFrequencyDurationTiming, andRate of change of flow

Recommendations (Continued)Framework for adopting alternative methods for F&W flows

into Arkansas Water Plan (i.e., adaptive management), which requires:

1. Defining how flows were determined (e.g., USGS gauge) 2. Specifying the applicable stream classes (e.g. extraordinary

resource waters)3. Documenting the current hydrologic status 4. Confirming the flow-ecology relationships are scientifically

defensible5. Documenting the stakeholder process used to refine, if needed,

flows to achieve all designated uses6. Monitoring and periodically assessing flow-ecology relations

Recommendations (Continued)

Propose approaches for reducing the likelihood of declared water shortages and stopping withdrawals

For Illustration Only

Surface Water Quality

Information SourcesState-wide information sources

ADEQUSGS

Updated information since 1990 PlanSelected sources within water resources planning

regions Beaver Water District Ft. SmithCentral Arkansas WaterANRCAR Department of Health

AnalysesUsed existing results for current status

305(b) reports303(d) lists

Demand water use sectorsSummary by AR WR Planning RegionsWQ Trend analyses at concurrent water supply sitesFlow-adjusted Seasonal Kendall trend analysesIssues: since 1990 Plan and emerging

Current (2008) Water Quality:Impaired Stream Miles, Lake Acreage

Designated useWater Demand Sector

Use

Impaired Stream Miles/% of Total

Assessed

Impaired Lake Acres/% of Total

Assessed

Fish Consumption Recreation 363.3/3% 23,637/6%

Aquatic Life Fish & Wildlife 2,439.9/25% 11,248/3%

Primary Contact Recreation 564.8/6% 0

Secondary Contact Recreation 7/0.01% 0

Domestic Water Supply Drinking Water 448.3/4% 97,105/27%

Ag & Industrial Water Supply Agriculture, Industry 967.7/10% 0

Total miles (acres) impaired 4,086.5/41% 127,520/36%

Total miles (acres) assessed 9,849.7 357,896

Causes of Impairment (2008)Causes Stream Miles Lake Acres

Siltation/Turbidity 1,156.3 3,235Organic Enrichment/

Low DO/Nutrients 1,308 4,625

Mercury 319 18,677

Priority Organics 44.8 <10E. coli 638.8

Chlorides 691.7

Sulfates 511

Total Dissolved Solids 1,021.7

Beryllium 97,105

Copper 335

Unknown 30,485

Water Quality Change/Trend Stations

Parameters Analyzed*

DOInorganic NTKNTotal P

TurbidityTSSFecal Coliforms

*Parameters analyzed primarily related to aquatic life use

Fecal coliforms related to recreational use

Results of Q-adjusted Seasonal KendallNorth Planning Region

Stream NameWater Quality Trends

DO Inorganic N TKN Total Phosphorus Turbidity TSS

Kings River None None None None

Black River < 30 yrs None None

Strawberry River None None < 30 yrs None

Middle Fork Little Red R. < 30 yrs None

Illinois River <30 yrs <30 yrs < 30 yrs

Overall Surface Water Quality SummaryAssessed streams (59%) and lakes (64%) attained

uses No statewide patterns of use impairment or causes,

except fish consumption (mercury) since 1990Declining trends in suspended solids across most

water resources planning regionsPotential emerging concern – trace organics known

as CECs

How to Follow the Arkansas Water Planning Process and Get More InformationVisit the Water Plan Website at:

ARWaterPlan.Arkansas.govSend an e-mail to:

ArkansasWater@CDMSmith.comProvide us your address and we

will send periodic updatesVisit the ANRC website to follow

Commission activities

anrc.arkansas.gov/

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