Alamosa River Watershed Plan

• Document ID: 0001
• County: Rio Grande
• County: Conejos
• County: Costilla
• County: Saguache
• Stream Name: Alamosa River
• Basin: Rio Grande
• Sub-Basin: Alamosa-Trinchera 13010002
• Water Division: 3
• Title: Alamosa River Watershed Restoration Master Plan and Environmental Assessment
• Date: 7/1/2005
• Prepared For: CWCB
• Prepared By: MWH
• Watershed Pro - Doc Type: Planning Report

Section 3.0 - Development of THE Watershed Restoration Plan (Proposed Actions) ...............3-1
3.1 Overall Strategy for Restoration Planning ........................................................................................... 3-1
3.1.1 Watershed Restoration ~rision ..................................................................................................................................... 3-1
3.1.2 Restoration Project Planning Process ........................................................................................................................ 3-2
3.2 Evaluation of Natural Resources Impacts ........................................................................................... 3-3
3.3 Process of nalyzing Potential Restoration Pro~ects ......................................................................... 3-5
3.3.1 Universe of Projects ..................................................................................................................................................... 3-5
3.3.2 Project Evaluation Criteria .......................................................................................................................................... 3-9
3.4 River Channel and Adjacent Corridor ................................................................................................ 3-10
3.4.1 Stream Restoration ...................................................................................................................................................... 3-10
3.4.2 Dead Tree Management ............................................................................................................................................. 3-14
3.4.3 Flood Control .............................................................................................................................................................. 3-15
3.5 dater Quantity Improvement .............................................................................................................3-16
3.5.1 Development of Instream Flow ................................................................................................................................ 3-17
3.5.2 Change in Terrace Reservoir Operations for Instream Flow Storage ................................................................. 3-19
3.5.3 New Reservoirs ........................................................................................................................................................... 3-21
3.5.4 ~~quifer Storage for Instream Flow ........................................................................................................................... 3-24
3.5.5 Water Quantity Projects Eliminated from Further Consideration ....................................................................... 3-25
3.6 Ground dater Improvement .............................................................................................................. 3-25
3.7 Terrace Reservoir Improvements ....................................................................................................... 3-25
3.7.1 Increase Spillway Capacity ......................................................................................................................................... 3-26
3.7.2 Raise Crest of Dam ..................................................................................................................................................... 3-29
3.7.3 Sediment Removal to Increase Capacity .................................................................................................................. 3-30
3.7.4 Improvements to Outlet Works ............................................................................................................................... 3-31
3.7.5 Power Generation at Terrace Reservoir .................................................................................................................. 3-32
3.8 Sediment Management ......................................................................................................................... 3-32
3.8.1 Lower Watershed Sediment Deposition Locations ................................................................................................ 3-33
3.8.2 Road Management in Upper Watershed .................................................................................................................. 3-33
3.8.3 Sediment Traps at Upper Tributary Confluences ................................................................................................... 3-34
3.9 dater Qua ty Improvement ................................................................................................................3-39
3.9.1 Reclamation of ~~bandoned Mines Other Than Summitville ............................................................................... 3-39
3.9.2 Passive Water Quality Improvement on l~ltered Tributaries ................................................................................ 3-41
3.9.3 ~~ctive Water Quality Improvement on ~~ltered Tributaries ................................................................................. 3-45
3.9.4 Lake or Reservoir on 1-~lamosa River below Wightman Fork ............................................................................... 3-46
3.9.5 Consolidation of Tributaries for 1-fictive Water Quality Improvement ................................................................ 3-49
3.9.6 Conveyance of Tributaries to 1-~rea of l~lkaline Soils ............................................................................................. 3-50
3.9.7 Summer Land ~~pplication of ~-acidic Flows ............................................................................................................ 3-51
3.9.8 Winter Freezing of ~-acidic Flows .............................................................................................................................. 3-51
3.9.9 Water Quality Projects Eliminated From Future Consideration .......................................................................... 3-52
3.10 Riparian Habitat .....................................................................................................................................3-53
3.10.1 Noxious Weed i~Ianagement ..................................................................................................................................... 3-53
3.10.2Revegetation ofDisturbed Riparian ~~reas in the Lower Watershed ................................................................... 3-54
3.10.3 Grazing i~Ianagement ................................................................................................................................................. 3-55
3.10.4Riparian Buffer Zone ................................................................................................................................................. 3-57
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3.10.5~~c uisition of E uwalent Resource in San Luis ~~ alle 3-57
q q Y .........................................................................................
3.10.6Purchase Land Downstream of Wightman Fork for Recreation and Habitat .................................................... 3-58
Alamosa River Watershed Restoration Master Plan and Environmental Assessment Page iii