COLDWATER RIVER Sensitive Habitat Inventory and Mapping and Aquatic Habitat Index Prepared By: Ecoscape Environmental Consultants Ltd. Prepared for: Fraser Basin Council March 2021 COLDWATER RIVER Sensitive Habitat Inventory and Mapping and Aquatic Habitat Index Prepared For: FRASER BASIN COUNCIL Prepared By: ECOSCAPE ENVIRONMENTAL CONSULTANTS LTD. # 102 - 450 Neave Court Kelowna, BC V1V 2M2 March 2021 Ecoscape File: 18-2715 102 – 450 Neave Ct. Kelowna BC V1V 2M2 Tel: 250.491.7337 Fax: 250.491.7772 www.ecoscapeltd.com 18-2715 March 2021 ACKNOWLEDGEMENTS This project would not have been realized without the assistance and contribution from the following individuals and organizations: • Department of Fisheries and Oceans Canada – for their support and expertise in development of the RIM methodology and Aquatic Habitat Index as it was first developed for the Lower Shuswap River project and adapted to subsequent projects including the Coldwater River. Support for this project was provided by: Nicola Watershed Stewardship and Fisheries Authority (NWSFA) Nicola Tribal Association (NTA) Nicola Valley Institute of Technology (NVIT) Field Inventory Crew: Scott McGill, Ecoscape Environmental Consultants Ltd Kyle Hawes, Ecoscape Environmental Consultants Ltd Josh Castanier, Ecoscape Environmental Consultants Ltd Jerome Abbot, Nicola Valley Institute of Technology The following parties contributed to the development of the Aquatic Habitat Index: Kyle Hawes, Ecoscape Environmental Consultants Ltd Jason Schleppe, Ecoscape Environmental Consultants Ltd Bob Harding, Fisheries and Oceans Canada Bruce Runciman, Fisheries and Oceans Canada The principal author of this report was: Scott McGill, B.Sc., R.P.Bio. Ecoscape Environmental Consultants Ltd Contributing author and supervisor was: Kyle Hawes, B.Sc. R.P.Bio, Ecoscape Environmental Consultants Ltd Geographical Information Systems (GIS) mapping and analysis was prepared by: Robert Wagner, Ecoscape Environmental Consultants Ltd Luke Crevier, Ecoscape Environmental Consultants Ltd Recommended Citation: McGill, S., R. Wagner, L. Crevier, and K. Hawes. 2021. Coldwater River Inventory, Mapping, and Aquatic Habitat Index. Ecoscape Environmental Consultants Ltd. Project File: 18-2715. 47pp + maps & appendices. 102 – 450 Neave Ct. Kelowna BC V1V 2M2 Tel: 250.491.7337 Fax: 250.491.7772 www.ecoscapeltd.com 18-2715 ii March 2021 INFORMATION DISCLAIMER The results contained in this report are based upon data collected during a single season inventory. Biological systems respond differently both in space and time. For this reason, the assumptions contained within are based upon field results, previously published material on the subject, and airphoto interpretation. The material in this report attempts to account for some of the variability between years and in space by using safe assumptions and a conservative approach. Data in this assessment was not analyzed statistically and no inferences about statistical significance are made if the word significant is used. Use of or reliance upon biological conclusions made in this report is the responsibility of the party using the information. Neither Ecoscape Environmental Consultants Ltd., nor the authors of this report is liable for accidental mistakes, omissions, or errors made in preparation of this report because best attempts were made to verify the accuracy and completeness of data collected, analyzed, and presented. This is intended as a “Living Document”. In so being, it may be continually edited and updated and may evolve and be expanded as needed, and serve a different purpose over time. #102 – 450 Neave Ct. Kelowna, BC V1V 2M2 tel: 250.491.7337 fax: 250.491.7772 web: www.ecoscapeltd.com 18-2715 iii March 2021 EXECUTIVE SUMMARY A comprehensive inventory was completed for the Coldwater River (CWR) in July of 2020 from the headwater at the west end of Upper Coldwater Road to the Nicola River confluence in the City of Merritt. The results of this data were used to complete an Aquatic Habitat Index (AHI). This Large River Inventory and Mapping approach (RIM) adapts the data collection methods and standards of Sensitive Habitat Inventory and Mapping (SHIM) (Mason and Knight, 2001) and Foreshore Inventory and Mapping. The resultant AHI uses many different criteria, such as biophysical, fisheries values, and anthropogenic characteristics to estimate the relative habitat value of river reaches and bank segments that were defined during the inventory. The habitat index classifies this information in a 5-class system from Very High to Very Low. The CWR is a 5th order stream that flows a distance of approximately 95 km from its headwaters located within the Coquilhalla Pass at elevations over 1200m, meandering along British Columbia Highway 5 until its eventual confluence with the Nicola River at the west end of the City of Merritt. The watershed is snow dominated with summer low flows occurring in late August through to September, and late winter (Turcotte and Shrimpton, 2020). In total, the CWR supports populations of three of the seven species of pacific salmon; Coho (O. kisutch), Steelhead (O. mykiss) and Chinook (O. tshawytscha), as well as the non-anadromous forms (freshwater only) Rainbow Trout (O. mykiss). Other salmonid fish species include the Rocky Mountain Whitefish (Prosopium williamsoni) and Bull Trout (Salvelinus confluentus). Non-salmonid fish include suckers (Catastomus spp.), sculpin (Cottidae spp.), Redside Shiner (Richardsonius balteatus), Longnose Dace (Rhinichthys cataractae), Leopard Dace (Rhinichthys falcatus), and Pacific Lamprey (Entosphenus tridentatus). The CWR was divided into 25 reaches based on river channel morphology and character. The left bank (facing downstream) was divided into 156 segments and the right bank was broken into 174 Segments. The total length of the left and right river-banks was 93.1 km and 92.4 km, respectively. The predominant shore type along the right and left bank are high flood bench communities. Low and middle bench active floodplain site associations, combined, account for about 36% of the left bank and about 41% of the right bank. Both the left and right banks of the river are predominantly natural or have not been recently disturbed. While natural areas dominate the banks of the Coldwater River, medium to high-level impacts account for about 30% and 32% of the left and right banks respectively. Commercial and industrial land use encroachment/confinement and disturbance was observed primarily in Merritt and occurs along about 1.0% on both the left and right banks of the River. Agricultural land use occurs along 3.7% of the left bank and about 3.7% of the right bank. Rural land use occurs along about 11.2% of the left bank, and 23% of the right bank. Infrastructure accounts for about 3.2% and 4.4 % of the left and right banks respectively, which is largely a result of the 24 bridges recorded along the River. Physical habitat in the CWR was found very suitable for Chinook, Steelhead, and Coho production and the River has hosted significant historical spawning populations of Coho. Rearing areas include low flood benches, backwaters, side channels and sloughs adjacent to spawning areas. In the CWR, mapped backwaters amounted to about 0.87 ha, while side channels and seasonally inundated low flood benches accounted for about 14.64 ha and 38.72 ha respectively. #102 – 450 Neave Ct. Kelowna, BC V1V 2M2 tel: 250.491.7337 fax: 250.491.7772 web: www.ecoscapeltd.com 18-2715 iv March 2021 The Coldwater River was largely assessed as having a High Aquatic Habitat Index rating. High and Very High rated reaches were not separated since important habitat features and attributes occur over all segments. At the same time, there were no segment that received Low AHI scores. The centerline AHI analysis resulted in about 70% of the river ranked as High and the balance rated as Moderate. River bank segments scoring High and Very High accounted for 54% and 55% of the left and right bank respectively. Only 4 water withdrawals were recorded within the CWR channel. Shallow groundwater wells situated along the river, yet beyond the channel (i.e., in field and rural/agricultural lands throughout expansive mid and high flood benches along the CWR) were not mapped during the field survey. Water withdrawals can directly impact fish as fry can become trapped and lost in withdrawal canals. Initiative should be taken to ensure water withdrawals are properly screened to prevent small-bodied fish and fry entrainment. In addition to direct effects on fish, extensive water withdrawals (from both instream and shallow groundwater wells on the floodplain) can exacerbate the risks associated with low river flows triggered by climate variability. Low summer flows have the potential to diminish the availability of suitable spawning habitat for a variety of fish species as waters recede through low floodplains and riverine marshes. Low flows have the added risk of stranding, trapping rearing juveniles in high quality backwater habitats, where survival depends on the availability of food, cover, and cool waters. Furthermore, low summer flows further elevate the risk to fish associated with elevated stream temperatures and increased stress on fish, which can lead to lethal consequences. Fish species such as Coho may be forced to use lower reaches as low flows result in inaccessibility to formerly used higher reaches. For these reasons it is paramount that landuse planning and management of the CWR focus on conservation and restoration of floodplain