Virgin River Watershed Management Plan
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Virgin River Watershed Management Plan February 2006 Virgin River Watershed Management Plan i Contents Section One Watershed Management Planning . I-1 The Virgin River Watershed . I-1 Watershed Management . I-2 Watershed Management Planning . .I-4 Watershed Management Activities in the Virgin River. I-5 Current Watershed Planning Activites . .I-6 Total Maximum Daily Load I-6 Drinking Water Source Protection Plan I-8 Storm Water Management Plans I-8 The Virgin River Watershed Management Plan I-9 Use of the Watershed Management Plan . I-11 Virgin River Watershed Management Plan Mission Statement . I-13 Section Two Overview of the Virgin River Watershed . II-1 Natural Features of the Virgin River Watershed . II-2 Soils II-2 Topography II-2 Climate and Hydrology II-4 Wildlife II-4 Human Factors . II-5 Land Use II-5 Population Growth and Trends II-6 Land Ownership II-8 Stakeholders II-8 Section Three Virgin River Watershed Key Concerns. III-1 A Snapshot of the Virgin River Watershed: Establishing Overall Baseline Conditions . III-2 Water Quality III-2 Water Quantity III-8 Biological Community III-9 Habitat. .III-9 Wildlife. III-10 Contents ii Virgin River Watershed Management Plan Stakeholders’ Key Issues in Watershed Planning Areas . III-12 Water Quality Problems and Natural Resources III-13 Dissolved Solids III-14 Sedimentation III-17 Lack of Stream Flow III-18 Nutrients III-19 Healthy Land III-20 Healthy Fish and Animals III-22 Watershed Planning Area: East Fork Virgin River III-22 What.Are.Stakeholders’.Key.Concerns?. III-24 Riparian.Corridor.Health . III-24 Stream.Flow.Management . III-24 Erosion.Control. III-24 Threatened.and.Endangered.Species . III-24 Pinyon-Juniper.Management. III-25 Wastewater.Disposal.and.Septic.Systems . III-25 Watershed Planning Area: North Fork Virgin River III-25 What.Are.Stakeholders’.Key.Concerns?. III-27 Natural.Stream.Function. III-27 Threatened.and.Endangered.Species . III-27 Wastewater.Disposal. III-27 Recreation. III-28 Watershed Planning Area: Upper Virgin River III-28 What.Are.Stakeholders’.Key.Concerns?. III-28 Riparian.Corridor.Health . III-28 Natural.Erosion . III-30 Threatened.and.Endangered.Species . III-30 Wastewater.Disposal.and.Septic.Systems . III-30 Watershed Planning Area: Ash Creek/La Verkin Creek III-30 What.Are.Stakeholders’.Key.Concerns?. III-32 Maintenance.of.Year.Round.Flow.Flow . III-32 Riparian.Corridor.Health . III-32 Wastewater.Disposal.and.Septic.Systems . III-33 Threatened.and.Endangered.Species . III-33 Vegetation.Management . III-33 Watershed Planning Area: Lower Virgin River III-35 What.Are.Stakeholders’.Key.Concerns?. III-35 Floodplain.Management . III-35 Wastewater.Disposal. III-36 Threatened.and.Endangered.Species . III-36 Water.Quality.Monitoring . III-36 Contents Virgin River Watershed Management Plan iii Watershed Planning Area: Upper Santa Clara River III-37 What.Are.Stakeholders’.Key.Concerns?. III-37 Riparian.Corridor.Health . III-37 Runoff.Storage.Through.Reservoirs. III-39 Wastewater.Disposal.and.Septic.Systems . III-39. Native.Species. III-39 Watershed Planning Area: Lower Santa Clara River III-39 What.Are.Stakeholders’.Key.Concerns?.. III-41 Riparian.Corridor.Health . III-41 Maintenance.of.Year.Round.Flow.Conditions . III-41 Increased.Off-Highway.Vehicle.Activity.. III-42 Native.Species. III-42 Water.Quality.Monitoring . III-42 Watershed Planning Area: Beaver Dam Wash/Fort Pearce Wash III-42 What.Are.Stakeholders’.Key.Concerns?. III-44 Water.Quality.Monitoring . III-44 Threatened.and.Endangered.Species . .III-44 Watershed-Wide.Key.Concerns. III-45 Ground.Water. III-45 Social.Considerations . III-45 Public.Education.and.Outreach. III-46 Section Four Strategic Action Plan. IV-1 Selecting Appropriate Watershed Management Practices . IV-3 Potential Causes of Stream Impairment . IV-3 Recommended Management Practices for the Virgin River Watershed . IV-5 Watershed-Wide Issues and Recommended Management Practices . IV-6 Maintenance of Stream Flow IV-6 Recommendations.to.help.maintain.continuous.and.year-round.flow. IV-9 Dissolved Solids IV-9 Recommendations.to.decrease.dissolved.solids . IV-10 Nutrients IV-10 Recommendations.to.reduce.nutrient.levels. IV-11 Stream and Land Changes IV-11 Land.Use.Recommendations . IV-12 Stream.Recommendations. IV-12 Flooding IV-13 Flooding.Recommendations .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. IV-13 Wildfires IV-13 Recommendations. IV-14 Contents iv Virgin River Watershed Management Plan Native Fishes IV-14 Recommendations.for.Recovery.of.Native.Fishes. IV-15 Ground Water IV-16 Recommended.Management.Practices.to.Protect.Groundwater.and.. Understand.Groundwater.Resources . IV-16 Social Considerations IV-18 Recommendations.to.address.Social.Considerations. IV-18 Public Education and Outreach IV-18 Plan.to.educate.and.reach.out.to.the.public. IV-19 Recommended Activities and Management Practices for Key Issues and Concerns by Watershed Planning Area . IV-19 East Fork Virgin River IV-19 Stream.Bank.Stabilization . IV-20 North Fork Virgin River IV-20 Maintenance.of.Minimum.Flow . IV-21 Threatened.and.Endangered.Species . IV-21 Wastewater.Disposal.and.Septic.System.Density. IV-22 Recreation. IV-22 Upper Virgin River IV-23 Pah.Tempe.Hot.Springs . IV-23 Ash Creek/La Verkin Creek IV-25 Maintenance.of.Natural.Flow.Conditions. IV-26 Riparian.Corridor.Health . IV-27 Wastewater.Disposal.and.Septic.Systems.. IV-27 Threatened.and.Endangered.Species . IV-27 Vegetation.Management . IV-27 Lower Virgin River IV-27 Floodplain.Management. IV-28 Wastewater.Disposal.and.Septic.Systems. IV-29 Threatened.and.Endangered.Species. IV-29 Water.Quality.Monitoring . IV-30 Upper Santa Clara River IV-31 Riparian.Corridor.Health . IV-31 Runoff.Storage.Through.Reservoirs. IV-32 Wastewater.Disposal.and.Septic.Systems.. IV-32 Threatened.and.Endangered.Species . IV-32 Lower Santa Clara River IV-32 Riparian.Corridor.Health . IV-33 Maintenance.of.Year.Round.Stream.Flow.. IV-33 Increased.Off-Highway.Vehicle.Activity. IV-34 Contents Virgin River Watershed Management Plan v Threatened.and.Endangered.Species . IV-34 Water.Quality.Monitoring . IV-34 Beaver Dam Wash/Fort Pearce Wash IV-35 Water.Quality.Monitoring . IV-36 Summary of Watershed Problems and Concerns . IV-36 Recommended Projects to Address Problems and Issues in the Watershed . IV-38 Ranking of Projects IV-39 Watershed Management . IV-39 Section Five References . V-1 Contents vi Virgin River Watershed Management Plan Contents Virgin River Watershed Management Plan I-1 Section One Watershed Management Planning The Virgin River Watershed HE VIRGIN RIVER WATERSHED is an area Tof land that covers portions of southwest Utah, southeast Nevada, and northwest Arizona (Figure I-1). To trace the Virgin River watershed on a map, you would begin in the southwestern corner of Iron County and trace the watershed boundary in a southeasterly direction into Washington County, through the Dixie National Forest where Moody Wash and Magotsu Creek begin to form the Santa Clara River. Follow the boundary of the Virgin River watershed east along the northern portion of Washington County past Route 18, where it dips south again, and heads north back into Iron County moving east past Kanarraville and Route 16 and past Route 14. Here the watershed boundary begins to dip south again, crossing into Kane County where Deep Creek and the North Fork of the Virgin River have their origin. The boundary rises north to where Routes 14 and 89 intersect, just west of Alton, Section One Watershed Management Planning I-2 Virgin River Watershed Management Plan and then runs south parallel to Kanab Creek just east of Glen- What Is a Watershed? dale, Orderville, Mount Carmel and Mount Carmel Junction. A watershed is a geographic area that drains If you wanted to trace the boundaries of the entire Virgin River to a common outlet such as a point on a watershed, you would cross the Nevada and Arizona borders. larger stream, a lake, an underlying aquifer, Given that this plan focuses on the portion of the Virgin River an estuary, or an ocean. Natural features watershed within Utah’s boundaries, you can trace the Arizona- define the boundaries of a watershed, not Utah border as the southern boundary of the watershed and the political or jurisdictional boundaries. As a Nevada-Utah border as the western boundary of the watershed. result, watershed boundaries may transect However, the watershed itself never.