WETLAND RESTORATION CONCEPTUAL DESIGNS REPORT SALTESE FLATS WETLAND RESTORATION INVESTIGATION Spokane County, Washington Prepared for: SPOKANE COUNTY DIVISION OF UTILITIES PUBLIC WORKS BUILDING 1026 W. BROADWAY AVE. SPOKANE WA 99260 Prepared by: 1120 Cedar Street Missoula, MT 59802 March 2010 Project No. 100002604 Wetland Restoration Conceptual Designs Report Saltese Flats Wetland Restoration Investigation CONTENTS Page 1.0 INTRODUCTION ............................................................................................................................... 1 1.1 Purpose and Scope ...................................................................................................................... 5 1.2 Wetland Restoration Feasibility Overview ................................................................................. 5 2.0 CONCEPTUAL DESIGNS OVERVIEW .......................................................................................... 9 2.1 Conceptual Design Areas ............................................................................................................ 9 2.2 Restoration with Natural Hydrology ........................................................................................... 9 2.3 Restoration with Reclaimed Water .............................................................................................. 9 2.4 Potential Restoration Components and Concerns Common to ................................................. 10 All Concepts ...................................................................................................................................... 10 3.0 RESTORATION SCENARIOS ........................................................................................................ 18 3.1 Restoration to the Original Lake ............................................................................................... 18 3.2 Inundated Wetlands on Option Areas A and B ......................................................................... 20 3.3 Multiple Wetlands ..................................................................................................................... 22 3.4 Multiple Wetlands with Enhancements ..................................................................................... 24 3.5 Wetland/Crop Combination ...................................................................................................... 26 3.6 Visualizations ............................................................................................................................ 28 4.0 COSTS AND FUNDING .......................................................................................................... 33 5.0 NEXT STEPS ................................................................................................................................... 40 6.0 SUMMARY AND CONCLUSIONS ................................................................................................ 40 7.0 INFORMATION SOURCES ............................................................................................................ 41 APPENDICES APPENDIX A Cost Estimate Assumptions March 2010 ii .00 Wetland Restoration Conceptual Designs Report Saltese Flats Wetland Restoration Investigation TABLES Table 4-1. Saltese Flats Restoration: Natural Hydrology Cost Estimates .................................................. 34 Table 4-2. Saltese Flats Restoration: Reclaimed Water Cost Estimates .................................................... 35 Table 4-3. Saltese Flats Restoration: Permitting and NEPA/SEPA Cost Estimates .................................. 36 Table 4-4. Saltese Flats Restoration: Construction-Option Area A ........................................................... 37 Table 4-5. Saltese Flats Restoration: Construction-Option Area B ........................................................... 38 Table 4-6. Saltese Flats Restoration: Maintenance & Monitoring-Option Area A .................................... 39 FIGURES Figure 1-1. Saltese Flats Location................................................................................................................ 2 Figure 1-2. Saltese Flats Watershed Delineation ......................................................................................... 3 Figure 1-3. Saltese Flats Restoration Options .............................................................................................. 4 Figure 1-4. Saltese Flats Existing Features .................................................................................................. 8 Figure 2-1. Potential Berm and Shoreline Examples ................................................................................. 12 Figure 2-2. Public Access and Potential Trail System ............................................................................... 14 Figure 3-1. Restoration to Original Lake ................................................................................................... 19 Figure 3-2. Inundated Wetlands ................................................................................................................. 21 Figure 3-3. Multiple Wetlands ................................................................................................................... 23 Figure 3-4. Multiple Wetlands With Enhancements .................................................................................. 25 Figure 3-5. Wetland/Crop Option .............................................................................................................. 27 Figure 3-6. Option A Area Scenarios From Viewpoint 1 .......................................................................... 29 Figure 3-7. Option A Area Scenarios From Viewpoint 2 .......................................................................... 30 Figure 3-8. Option B Area Scenarios From Viewpoint 1 .......................................................................... 31 Figure 3-9. Option B Area Scenarios From Viewpoint 2 .......................................................................... 32 March 2010 iii .00 Wetland Restoration Conceptual Designs Report Saltese Flats Wetland Restoration Investigation 1.0 INTRODUCTION The Spokane County Division of Utilities is currently evaluating potential wetland restoration opportuni- ties at Saltese Flats. The Saltese Flats wetland restoration project could provide a variety of benefits in- cluding: • Delaying runoff to recharge the Spokane Valley-Rathdrum Prairie Aquifer to increase flow in the Spokane River during late summer months; • Restoring a diverse wildlife habitat area; • Providing a community resource for public recreation and education; and • Allowing for possible future beneficial use of Class A reclaimed water. This document presents and discusses a series of conceptual designs for wetland restoration options at Saltese Flats. Saltese Flats is located in Spokane County southeast of the city of Spokane Valley (Figure 1-1). The area known as Saltese Flats occupies roughly 1,200 acres of land that lies within a watershed of approximately 14,000 acres (Figure 1-2). The Flats includes land that currently functions as wetland, and also land that historically was a lake/wetland system but has been drained and used for agriculture for over one hundred years. Three wetland restoration option areas were considered during initial evaluation at Saltese Flats (Figure 1-3). Option Area A is 342 acres, Option Area B is 512 acres and Option Area C is approximately 1,200 acres. This report summarizes restoration opportunities on Option Areas A and B. These areas were determined to be sufficiently large to accommodate wetland restoration using both natu- ral hydrology and reclaimed water (PBS&J, 2010), and directly involve only two landowners. Wetland restoration is also feasible on other lands within Option Area C and could be undertaken in coordination with efforts on Option Areas A and B, or separately over time in response to landowner interest. Option Area C includes many landowners. This document represents the completion of the fourth phase of the Saltese Flats investigation completed by PBS&J under contract with the Spokane County Division of Utilities (Spokane County Utilities) in coordination with the WRIA 55/57 Watershed Implementation Team (WRIA 55/57 WIT), and with fund- ing from the Washington State Department of Ecology (Ecology). Previous phases include: 1. Development of a Scope of Work (PBS&J, 2008a) with subsequent update upon the completion of initial tasks (PBS&J, 2008e); 2. Development of Goals and Objectives for the project (PBS&J, 2008b); 3. A public meeting held on October 15, 2008 to introduce the project to interested parties, and a se- ries of meetings with the WRIA 55/57 WIT and a group known as the Wetland Panel, which was formed from a collection of stakeholders for this investigation; 4. Development of a Quality Assurance Program Plan, or QAPP (PBS&J, 2008c) and a Monitoring Program Plan (PBS&J, 2008d); 5. Completion of an evaluation and summary of existing information, including a preliminary site characterization and documentation in an Existing Data Review report (PBS&J, 2009); 6. Initiation of the Monitoring Program; and 7. Completion of a Data Update and On-Site Feasibility Report (PBS&J 2010). March 2010 1 .00 Wetland Restoration Conceptual Designs Report Saltese Flats Wetland Restoration Investigation Figure 1-1. Saltese Flats Location March 2010 2 .00 Wetland Restoration Conceptual Designs Report Saltese Flats