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:
[email protected] us your address and we
will send periodic updatesVisit the ANRC website to follow
Commission activities
anrc.arkansas.gov/
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