CITY OF OLYMPIA AND NISQUALLY INDIAN TRIBE McAllister Wellfield Mitigation Plan DECEMBER 2010 (Updated and resubmitted from September 2008) Nisqually Indian Tribe Photograph Courtesy of Nisqually Land Trust City of Olympia and Nisqually Indian Tribe McAllister Wellfield Mitigation Plan December 2010 (Updated and resubmitted from September 2008) For more information, contact: Rich Hoey, P.E. Joe Cushman Director of Water Resources Planning Director City of Olympia, Public Works Department Nisqually Indian Tribe (360) 753-8495 (360) 456-5221 Fax (360) 753-8087 Fax (360) 456-4838 E-mail: [email protected] E-mail: [email protected] To request this Plan in an alternate format, please call 360.753.8769 or 360.753.8270 (TTY) during normal office hours to arrange for a reasonable accommodation, or mail a written request to Heather Reed, City of Olympia, P.O. Box 1967, Olympia, WA 98507-1967 The City of Olympia is committed to the non-discriminatory treatment of all persons in employment and the delivery of goods and services. Table of Contents 1.0 Introduction 1.1 Olympia’s Existing Source – McAllister Springs ......................................................... 8 1.2 Nisqually Indian Tribe’s Existing Source ..................................................................... 9 1.3 McAllister Wellfield – Background .............................................................................. 9 1.4 City of Olympia Water Right Change Applications ................................................... 12 1.5 Planned Wellfield Facilities and Operations ............................................................... 13 1.5.1 Phase I of Well Development Schedule ......................................................... 14 1.5.2 Phase II of Well Development Schedule ........................................................ 14 1.5.3 Phase III of Well Development Schedule ...................................................... 14 2.0 Predicted Water Resource Impacts 2.1 Water Bodies of Interest ............................................................................................. 15 2.2 Numerical Model of Groundwater System ................................................................. 16 2.2.1 Model Accuracy for Predicting Small Depletions .......................................... 19 2.3 Model Results – McAllister Wellfield ........................................................................ 19 2.3.1 Predicted Impacts on Modeled Surface Water Bodies ................................... 20 2.3.2 Cumulative Model Results ............................................................................. 22 2.3.3 Potential Impacts on Nearby Wells ................................................................ 23 3.0 Mitigation Alternatives, Phasing and Approach 3.1 Mitigation Alternatives Screening Process ................................................................. 27 3.2 Olympia and Nisqually Tribe Shared Mitigation Approach ....................................... 29 3.3 Phasing of Mitigation Program ................................................................................... 29 3.4 Stewardship ................................................................................................................. 30 4.0 Nisqually Indian Tribe’s Mitigation Program 4.1 Tacoma Power Element .............................................................................................. 31 4.2 Groundwater Protection Zone Element ....................................................................... 32 4.2.1 Groundwater Protection Zone Ordinance ....................................................... 32 4.2.2 Hydrogeology and Expected Benefits ............................................................ 33 4.2.3 Groundwater Model Results ........................................................................... 34 4.2.4 Expected Benefits from the Groundwater Protection Zone ............................ 34 4.3 Habitat Restoration Element ....................................................................................... 35 4.3.1 Ohop Creek Restoration ................................................................................. 36 4.3.2 Muck Creek Restoration ................................................................................. 37 4.3.3 Other Restoration Projects in the Nisqually Watershed ................................. 37 5.0 City of Olympia’s Mitigation Program 5.1 McAllister Creek ......................................................................................................... 40 5.2 Lake Saint Clair .......................................................................................................... 41 5.3 Woodland Creek Basin ............................................................................................... 43 5.3.1 Olympia's Predicted Depletions ..................................................................... 43 McAllister Wellfield Mitigation Plan i City of Olympia and Nisqually Indian Tribe 5.3.2 Predicted Depletions and Mitigation Quantities for Regional Mitigation in Woodland Creek Basin ............................................................................... 43 5.3.3 Regional Flow Mitigation for the Woodland Creek Basin: Reclaimed Water Infiltration ............................................................................................ 45 5.3.4 Regional Non-flow Mitigation for Woodland Creek: Riparian Land Protection ........................................................................................................ 50 5.4 Deschutes River Basin ................................................................................................ 52 5.4.1 Olympia's Predicted Depletions ..................................................................... 52 5.4.2 Predicted Depletions for Olympia, Lacey and Yelm in the Deschutes River Basin ..................................................................................................... 52 5.4.3 Flow Mitigation Using Water Rights Acquisitions ........................................ 53 5.4.4 Non-Flow Land Acquisition and Habitat Restoration .................................... 59 5.4.5 City of Olympia Share of Non-Flow Mitigation ............................................ 65 5.5 Groundwater Drawdown Effects ................................................................................ 65 6.0 Conclusion .............................................................................................................................. 67 References Tables Table 1-1 McAllister Springs and Abbott Springs Water Rights Quantities ..................................... 12 Table 1-2 McAllister Wellfield Monthly Pump Rates at Full Production ......................................... 13 Table 1-3 Preliminary Schedule of Well Development ..................................................................... 14 Table 2-1 Regulatory Status of Key Water Bodies in WRIAs 11 and 13 ......................................... 15 Table 2-2 Annual and Summer Depletions Predicted for Surface Water Bodies .............................. 21 Table 3-1 Anticipated Implementation of Mitigation Actions .......................................................... 30 Table 4-1 Predicted Depletions at 3 MGD Allotment ....................................................................... 35 Table 5-1 Regional Mitigation Program: Model-Predicted Depletions for Woodland Creek Basin .................................................................................................................................. 44 Table 5-2 Regional Mitigation Program: Calculated Mitigation Quantities for Woodland Creek Basin ........................................................................................................................................... 44 Table 5-3 Maximum Estimated Changes to Lake Levels .................................................................. 45 Table 5-4 Regional Mitigation for Woodland Creek: Mitigation with Reclaimed Water ................. 48 Table 5-5 Regional Mitigation Program: Model-Predicted Depletions for Deschutes River Basin ............................................................................................................................53 Table 5-6 Regional Package of Deschutes River Water Right Acquisitions ..................................... 54 Table 5-7 Deschutes Flow Mitigation by Reach for Closure Period – McAllister Wellfield Predicted Depletions ......................................................................................................................... 55 Table 5-8 Winter Flow Depletion Impact Calculation for Cities of Olympia, Lacey and Yelm ....... 60 Table 5-9 Deschutes Property Acquisition and Habitat Restoration: Schedule for Completing Actions .............................................................................................................................. 65 McAllister Wellfield Mitigation Plan ii City of Olympia and Nisqually Indian Tribe Table 6-1 Summary of Partnered Mitigation Strategies .................................................................... 68 Table 6-2 Proposed Implementation of Closure Period Flow Mitigation for Modeled Water Bodies by Phase (AFY) ................................................................................................................. 69 Table 6-3 Proposed Implementation of Non-Flow Mitigation for Modeled Water Bodies by Phase ................................................................................................................................