Wetland Classification and Geologic Assessment Report: Gabriola Island Water Region (WR7-GI) Prepared for: Regional District of Nanaimo’s Drinking Water and Watershed Protection Program Prepared by: Mount Arrowsmith Biosphere Region Research Institute December 2019 Wetland Classification and Geologic Assessment Report: Gabriola Island Water Region Acknowledgments A special thank you is extended to Julie Pisani, Coordinator of the Drinking Water and Watershed Protection Program (DWWP) at the Regional District of Nanaimo (RDN), for her continual support and guidance throughout this project. We would also like to thank our team of advisors for this project including, Vancouver Island University (VIU) Geography Department faculty member and RDN DWWP Technical Advisory Committee board member, Dr. Alan Gilchrist PhD PGeo., as well as VIU Earth Science Department faculty member, Dr. Jerome Lesemann PhD. Another special thank you to former Project Coordinator of the Mid-Vancouver Island Habitat Enhancement Society (MVIHES) and lifelong active community member and environmental steward, Faye Smith Rosenblatt. Her passing has been a great sadness and we are exceedingly grateful for the care and contributions she made to this research project and to the Mount Arrowsmith Biosphere Region (MABR) as a whole. We would like to extend further thanks to Bernd Keller, member of MVIHES, for his continual support and collaboration with this project moving forward. We continue to be thankful to the members of the public and property owners for welcoming our researchers on to their lands to conduct our research, as well as for engaging and showing interest in the purpose and longevity of this project. Research Project Team Wetland Project Coordinators Research Assistants Jessica Pyett Alanna Vivani Haley Tomlin Jenica Ng-Cornish Ashley Van Acken GIS & Remote Sensing Specialists Ariel Verhoeks 2 | Page Wetland Classification and Geologic Assessment Report: Gabriola Island Water Region Table of Contents 1.0 Introduction 6 2.0 Methods 7 - 9 2.1 Preliminary Research Steps 7 - 8 2.2 Field Steps 8 - 9 3.0 Regional Description 9 - 12 3.1 Physiography 9 3.2 Regional Geology 9 - 12 3.2.1 Bedrock Geology 9 - 11 3.2.2 Stratigraphic Framework 11 - 12 4.0 Gabriola Island Water Region Study Sites 12 - 19 4.1 Gabriola Island 12 - 13 4.1.1 Surficial Materials Gabriola Island 13 4.1.2 WR7-GI-01 Wetland Observations and Classification 13 - 14 4.1.3 WR7-GI-02 Wetland Observations and Classification 15 4.1.4 WR7-GI-03 Wetland Observations and Classification 16 - 17 4.1.5 WR7-GI-04 Wetland Observations and Classification 17 - 18 4.1.6 WR7-GI-05 Wetland Observations and Classification 18 - 19 5.0 Discussion 20 - 24 5.1 Hydrostratigraphy 20 - 21 5.2 Wetland Characteristics 21 - 22 5.3 Recommendations 22 - 24 5.3.1 Cross-Sectional Analysis 22 - 23 5.3.2 Geophysical Surveys 23 5.3.3 Installation of Instrumentation 23 - 24 6.0 Conclusion 24 7.0 References 25 - 27 Appendix A: Summary of Wetland Classification and Aquifer Characteristics 28 Appendix B: Mapped Aquifers in the Gabriola Island Water Region 29 3 | Page Wetland Classification and Geologic Assessment Report: Gabriola Island Water Region List of Figures Figure 1: Wetland Sites within the Gabriola Island Water Region 7 Figure 2: Simplified Stratigraphic Units of the Nanaimo Group 11 Figure 3: Late Quaternary Deposits and Corresponding Event Sequence 12 Figure 4: WR7-GI-01 14 Figure 5: WR7-GI-02 15 Figure 6: WR7-GI-03 17 Figure 7: WR7-GI-04 18 Figure 8: WR7-GI-05 19 Figure 9: Example Distribution of Materials and Their Relationship to 21 Stratigraphy and Hydrostratigraphy 4 | Page Wetland Classification and Geologic Assessment Report: Gabriola Island Water Region Abstract Significant data gaps exist within the Regional District of Nanaimo (RDN) in regards to wetland locations, classifications, and what role they have in groundwater recharge. While there has been recent interest in regional freshwater resources within the RDN’s watersheds, there are relatively few studies that have inventoried wetlands and investigated their localized connection to groundwater resources. Our objectives in this study were to: 1) ground truth predictive mapping that showed the distribution of potential wetland sites in the Gabriola Island Water Region; 2) create an inventory of wetlands in the Gabriola Island Water Region; and 3) evaluate each site’s hydrogeological position to gain a better understanding of water storage, discharge, and potential flow pathways at each site. Researchers found that there were various types of wetlands in the region including swamps, marshes, bogs, and shallow water. Many of these systems had secondary classifications that were unique to each site as a result of localized conditions. At the time the sites were visited, most of the wetlands contained water or had diffuse or central patches of water. By monitoring the health of these systems and investigating subsurface conditions through desktop analysis, geophysical surveys, and instrumentation, it should be possible to develop new management practices while also identifying any potential connections between surface water and groundwater systems. It should be noted that wetlands were mapped based on accessibility and permission from landowners; these findings may not be representative of all wetlands that exist across the entire water region. Overall, results from this study will provide a framework for understanding how localized wetland systems contribute to both local and regional freshwater systems, while also informing land use and planning decisions across the RDN. 5 | Page Wetland Classification and Geologic Assessment Report: Gabriola Island Water Region 1.0 Introduction The Regional District of Nanaimo (RDN) is located on the eastern coast of Vancouver Island, British Columbia. Geographically, the RDN comprises an area that extends from the northern point of Deep Bay to the southern point of Cedar and includes Gabriola, Mudge, and DeCourcy Islands. There are four municipalities within the RDN that are home to over 155,000 people and include the City of Nanaimo, District of Lantzville, City of Parksville, and Town of Qualicum Beach (Regional District of Nanaimo, 2019a). Seven major water basins divide this area and are referred to as water regions in this report. The water regions include: Big Qualicum, Little Qualicum, French Creek, Englishman River, South Wellington to Nanoose, Cedar-Yellow Point/Nanaimo River, and Gabriola Island (Waterline Resources Inc., 2013). This document focuses on Water Region 7 (WR7), the Gabriola Island Water Region (Figure 1). WR7 encompasses an area of approximately 5,636 ha and is comprised of three of the southern sub-group of Gulf Islands: Gabriola, DeCourcy, and Mudge, all populated islands off of the east coast of Nanaimo (Regional District of Nanaimo, 2019b). This report will discuss wetlands mapped in this region and connect field observations with literature to better understand impacts of surrounding land uses while also developing a better understanding of potential connections between surface water and groundwater systems. To accomplish this, our report will highlight field methods used for wetland mapping, the physical geography and ecology of each wetland, as well as regional geology, with a focus on the hydrology and surrounding land uses. Developing baseline data on the ecological and geological relationships within wetlands will be crucial when trying to understand local impacts on ecology, as well as hydrological processes associated with groundwater recharge. 6 | Page Wetland Classification and Geologic Assessment Report: Gabriola Island Water Region Figure 1: Wetland Study Sites in Gabriola Island Water Region. Note DeCourcy Island is not shown. Sources: Imagery obtained from Esri’s online basemap database; water region boundaries obtained by the Regional District of Nanaimo; wetland site data collected in the field; map developed by MABRRI. 2.0 Methods 2.1 Preliminary Research Steps Prior to mapping a wetland in the field, the following preliminary research steps were taken: 1. Review predictive wetland maps that were created using Geographic Information Systems (GIS) and remote sensing based on existing data from Ducks Unlimited Workflow that combines the Government of British Columbia’s Sensitive Ecosystem Inventory (SEI), Pacific Estuary Conservation Program (PECP) polygons, and the Fresh Water Atlas (FWA) to determine the location and predictive classification of each site. 7 | Page Wetland Classification and Geologic Assessment Report: Gabriola Island Water Region 2. Determine which water region each wetland is located in using GIS software, specifically ArcMap 10.5, and associated RDN Water Region layers (RDN, 2018). 3. Identify proximal aquifers, including their classification number, type, level of demand, productivity, and vulnerability. This was completed using GIS software and associated groundwater layers provided by the Government of British Columbia’s Ministry of Environment (n.d.). 4. Review topographic maps, surficial deposit maps, well drilling data, satellite imagery, and GIS data to establish drainage basins, as well as localized inflows and outflows at wetland sites to provide an aerial perspective of the physical traits of each wetland. 5. Review satellite imagery to determine adjacent land uses to each wetland site. 6. Review parcel identification numbers provided by the RDN to determine property ownership in order to determine accessibility to wetland sites. 7. Create