• Water Quality

Potential At-Risk Maps and Information

The following are the potential at-risk maps produced during the Arkansas Resource Assessment - Phase I. The NRCS definition of the natural resource concern and the input layers and land use designation weights that were used for modeling the natural resource concerns within the Water Quality Degradation Resource Concern are listed to the right of each map. More detailed maps are available by clicking the link below each map.


Larger Map: View or Download
































Larger Map: View or Download
























Larger Map: View or Download


























Larger Map: View or Download










Larger Map: View or Download






Larger Map: View or Download
Excess Nutrients in Surface and Ground Waters

    NRCS Definition:
        Nutrients (organics and inorganics) are transported to receiving waters
        through surface runoff, leaching into shallow ground waters, or both in
        quantities that degrade water quality and limit use for intended purposes.

    Land Use Designation Weights:
        Crop and Pasture (Weight 3); Forest, Range, Urban
        and Assoc. Ag (Weight 1); Water (Weight 0)

    Binary Input Layers and Associated Weights:
        – SSURGO Flooding Frequency = Frequent (Weight 1)
        – SSURGO Representative Slope >= 3% (Weight 1)
        – SSURGO Hydrologic Soils Group A, B and D (Weight 1)
        – SSURGO Ksat > 14 and < 0.014 (Weight 2)
        – Karst, presence of Karst (Weight 2)
        – 303(d) Impairments by 12-digit HUC – Nutrient (Weight 3)
        – SSURGO Drainage Class, Excessively, Somewhat Excessively
                                                  Drained and Poorly, Somewhat Poorly or
                                                  Very Poorly Drained (Weight 2)

    Classified Input Layers and Associated Weights:
        – Acres of Manure Applied by County
            < 8,500 (Weight 0)
            8,500 – 13,700 (Weight 1)
            14,000 – 26,000 (Weight 2)
            28,000 – 50,000 (Weight 3)
        – Number of Animal Units by County
            < 25,000 (Weight 0)
            25,000 – 60,000 (Weight 1)
            70,000 – 100,000 (Weight 2)
            125,000 – 190,000 (Weight 3)
        – Acres of Commercial Fertilizer Applied by County
            < 70,000 (Weight 0)
            70,000 – 145,000 (Weight 1)
            150,000 – 250,000 (Weight 2)
            270,000 – 350,000 (Weight 3)



Pesticides/Herbicides Transported to Surface
and Ground Waters


    NRCS Definition:
        Pesticides are transported to receiving waters in quantities that degrade
        water quality and limit use for intended purposes.

    Land Use Designation Weights:
        Crop (Weight 3); Pasture (Weight 2); Forest, Range, Urban
        and Assoc. Ag (Weight 1); Water (Weight 0)

    Binary Input Layers and Associated Weights:
        – SSURGO Flooding Frequency = Frequently (Weight 1)
        – SSURGO Representative Slope >= 3% (Weight 1)
        – SSURGO Hydrologic Soils Group A, B and D (Weight 2)
        – SSURGO Ksat > 14 and < 0.014 (Weight 2)
        – Karst, presence of Karst (Weight 1)
        – 303(d) Impairments by 12-digit HUC – Pest/Herbicide (Weight 3)

Classified Input Layers and Associated Weights:
        – Acres of Herbicide Applied by County
            < 3,000 (Weight 0)
            3,000 – 9,000 (Weight 1)
            11,000 – 25,000 (Weight 2)
            48,000 – 75,000 (Weight 3)
        – Acres of Insecticide (including Nematicides) Applied by County
            < 8,900 (Weight 0)
            8,900 – 10,000 (Weight 1)
            14,000 – 20,000 (Weight 2)
            > 20,000 (Weight 3)



Excess Pathogens and Chemicals from
Manure, Biosolids or Composts


    NRCS Definition:
        Pathogens, pharmaceuticals, and other chemicals are transported to
        receiving  waters in quantities that degrade water quality and limit use for
        intended  purposes. This resource concern also includes the offsite
        transport of leachate  and runoff from silage, compost, or other organic
        materials.

    Land Use Designation Weights:
        Crop and Pasture (Weight 3); Forest, Range, Urban,
        and Assoc. Ag (Weight 1); Water (Weight 0)

    Binary Input Layers and Associated Weights:
        – SSURGO Flooding Frequency = Frequent (Weight 2)
        – SSURGO Soil Texture = Sandy or Loamy Sand soils (Weight 2)
        – SSURGO Depth to Water Table <= 15 (Weight 2)
        – SSURGO Surface Runoff = high, very high (Weight 2)
        – SSURGO Representative Slope >= 3% (Weight 2)
        – Karst, presence of Karst (Weight 2)
        – 303(d) Impairments by 12-digit HUC21 – Pathogens (Weight 3)

    Classified Input Layers and Associated Weights:
        – Acres of Manure Applied by County
            < 8,500 (Weight 0)
            8,500 – 13,700 (Weight 1)
            14,000 – 26,000 (Weight 2)
            28,000 – 50,000 (Weight 3)
        – Number of Animal Units by County
            < 25,000 (Weight 0)
            25,000 – 60,000 (Weight 1)
            70,000 – 100,000 (Weight 2)
            125,000 – 190,000 (Weight 3)



Excessive Salts in Surface and Ground Waters

    NRCS Definition:
        Irrigation or rainfall runoff transports salts to receiving water in quantities
        that  degrade water quality and limit use for intended purposes.

    Land Use Designation Weights:
        Crop (Weight 3); Pasture, Forest, Range, Urban,
        and Assoc. Ag (Weight 1); Water (Weight 0)

    Binary Input Layers and Associated Weights:
        – SSURGO Taxgrtgrp = Natraqualfs, Natrudalfs or Natrustalfs (Weight 1)
        – Cropped Portions of Southeast AR Groundwater
                                         Salinity Issues (Weight 1)
        – Farmers with Salt Issues (Weight 2)
        – 303(d) Impairments by 12-digit HUC – Salinity (Weight 1)



Petroleum, Heavy Metals, and Other Pollutants Transported to Water

    NRCS Definition:
        Heavy metals, petroleum, and other pollutants are transported to receiving
        water sources in quantities that degrade water quality and limit use for
        intended  purposes.

    Land Use Designation Weights:
        Crop, Pasture, Forest, Range, Urban and Assoc. Ag (Weight 1);
        Water (Weight 0)

    Binary Input Layers and Associated Weights:
        – 303(d) Impairments by 12-digit HUC – Metals (Weight 1)



Excessive Sediment in Surface Waters

    NRCS Definition:
        Offsite transport of sediment from sheet, rill, gully, and wind erosion into
        surface water that threatens to degrade surface water quality and limit use
        for intended purposes.

    Land Use Designation Weights:
        Crop (Weight 3); Forest (Weight 2); Pasture, Range, Urban,
        and Assoc. Ag (Weight 1); Water (Weight 0)

    Binary Input Layers and Associated Weights:
        – SSURGO Flooding Frequency = Frequent (Weight 2)
        – SSURGO Hydrologic Soils Group B and C (Weight 1)
        – SSURGO Ksat < 0.14 (Weight 2)
        – 303(d) Impairments by 12-digit HUC21 – Sediments (Weight 3)
        – Model results from the Stream Bank Erosion
                     Natural Resource Concern (Weight 3)

ċ
WaterQuality_At-RiskandPriorityMaps.zip
(8922k)
Hanna Ford,
Oct 6, 2011, 9:21 AM
Ċ
Hanna Ford,
Dec 2, 2011, 6:37 AM
Comments