Technical Assessment of the Shuswap River Watershed
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February 3, 2012 PHASE I - SHUSWAP RIVER WATERSHED SUSTAINABILITY PLAN Technical Assessment of the Shuswap River Watershed Submitted to: Laura Frank, Sustainability Coordinator Regional District of North Okanagan 9848 Aberdeen Road Coldstream, BC V1B 2K9 Report Number: 1114920047-002-R-Rev0 Distribution: REPORT Regional District of North Okanagan – 2 Bound Copies and 1 PDF Copy Golder Associates Ltd. - 1 Copy TECHNICAL ASSESSMENT OF THE SHUSWAP RIVER WATERSHED Executive Summary As requested by the Regional District of North Okanagan (RDNO), Golder Associates Ltd. (Golder) in collaboration with our sub-consultant Mr. Phil Epp, Consulting Hydrologist, is pleased to provide this Technical Assessment of the Shuswap River Watershed, mainly located in Electoral Areas “D” (Rural Lumby), “E” (Cherryville), and “F” (Rural Enderby) of the RDNO, in the Southern Interior of British Columbia. This Technical Assessment is part of Phase I of the larger Shuswap River Watershed Sustainability Plan (SRWSP), led by the RDNO, which involves an in-depth planning process with significant stakeholder and public engagement to establish a long-term vision for the management of the watershed, identify issues and data gaps, and develop objectives and actions for its future management. The purpose of this Technical Assessment is to establish a watershed profile for the Shuswap River Watershed, with a specific focus on its water quality, water quantity, and condition of riparian areas. This Technical Assessment was restricted to a desktop evaluation of the available information for the Shuswap River Watershed with baseline data and geographic information system mapping as the deliverables. The amount of information for this watershed is substantial. As such, and in consultation with the RDNO, primary efforts were focused on characterizing the water quality, water quantity, and condition of riparian areas associated with the main sub-drainages of this watershed. The Shuswap River Watershed is dominated by the Shuswap River and includes all of its direct and indirect sub- drainages. The Shuswap River originates from Joss Pass between Joss Mountain and Davis Peak in the Sawtooth Range of the Monashee Mountains. From its headwaters, the Shuswap River flows approximately 150 kilometres (km) down into the Shuswap Highlands and through two large lakes, Sugar Lake and Mabel Lake, before discharging into Mara Lake, which is a tributary lake of Shuswap Lake. The Shuswap River is commonly divided into the following three main sub-watersheds: the Upper Shuswap River Watershed (114,750 ha), which starts at Joss Pass and flows south, discharging into Sugar Lake (key sub-drainages: Greenbush Creek, Spectrum Creek, Outlet Creek); the Middle Shuswap River Watershed (292,403 ha), which starts at the Sugar Lake outlet and flows south and then north again into Mabel Lake (key sub-drainages: Cherry Creek, Ferry Creek, Duteau Creek, Bessette Creek, Wap Creek); and, the Lower Shuswap River Watershed (112,963 ha), which starts at the Mabel Lake outlet and flows to the west towards Enderby, eventually flowing north and discharging into Mara Lake (key sub-drainages: Kingfisher Creek, Trinity Creek, Fortune Creek). Each of these three identified sub-watersheds is characterized by unique biophysical and anthropogenic (i.e., human caused) regimes. As such, a separate profile has been developed for each sub-watershed as part of this Technical Assessment. The following sections provide a summary of the water quality, water quantity, and riparian areas results and discussion for the Shuswap River Watershed, with specific reference to each of the identified sub-watersheds. February 3, 2012 Report No. 1114920047-002-R-Rev0 TECHNICAL ASSESSMENT OF THE SHUSWAP RIVER WATERSHED Water Quality A high-level review of existing water quality data within the Shuswap River Watershed was undertaken as part of this Technical Assessment based on data presented in historical monitoring reports (academic, government, and consultant) concerning water usage, agriculture, industry, waste management, academic, and commercial stakeholders. These studies have predominantly focused on Mara Lake, Mabel Lake, Sugar Lake, Bessette Creek, Fortune Creek, and Brash Creek. Additional water quality data were obtained from BC Ministry of the Environment water wells in the Shuswap River Watershed, as well as from information warehoused in the RDNO’s WaterTrax online database. Water quality data for the Shuswap River Watershed were reviewed for broad trend and gap analysis, and were not subject to reinterpretation. As such, the water quality assessment in this Technical Assessment does not constitute a “source to tap” evaluation. Water quality comments are restricted largely to the following key parameters, where data were available: chloride and sodium (proxy for potential road salt impact; considered a conservative parameter for contaminant plume migration), nutrients (nitrate, nitrite, ammonia, ammonium, and phosphorous), and microbial parameters (E. coli and total coliforms). While the overall water quality of the Shuswap River Watershed is considered “good,” water quality impacts have been observed for nutrients and microbial parameters predominantly attributed to anthropogenic activities. Water quality in the Upper Shuswap River Watershed largely reflects nutrient and microbial impacts related to non- intensive agricultural and livestock activities as well as increased turbidity associated with high energy tributaries and freshet. Middle and Lower Shuswap River Watershed water quality data sets indicate an increasing impact to water resources from anthropogenic activities, largely consisting of elevated nutrients (waste management, septic disposal, agriculture, livestock). The limited nature of groundwater quality information prevents a detailed assessment of aquifer water quality. An extensive data mining and data warehousing program would greatly increase the amount of useful data available for interpretation and monitoring. Similarly, establishing a more comprehensive, consistent suite of analytical parameters and establishing a regular monitoring program for both surface water and groundwater at key locations across the Shuswap River Watershed would allow for the determination of representative background water quality and evaluation of short term and long term trends in water quality. A preliminary risk assessment was conducted for the Upper, Middle, and Lower Shuswap River Watershed based on land use designations, proximity to water sources, BC Contaminated Site Inventory Data, and data provided by the RDNO. This preliminary assessment identified potential areas of concern, largely related to intensive agriculture, waste management and wastewater treatment, and industry found within the Middle and Lower Shuswap River Watersheds. The Upper Shuswap River Watershed is considered to reflect a much lower risk to water quality due to the relatively minimal recreational, residential, and industrial infrastructure. Moderate and high risk rankings were given to land uses within the more densely populated areas within the Middle and Lower Shuswap River Watershed, such as those surrounding Lumby and Enderby, respectively. A limited “windshield” field program is recommended to confirm and revise the preliminary risk rankings. February 3, 2012 Report No. 1114920047-002-R-Rev0 TECHNICAL ASSESSMENT OF THE SHUSWAP RIVER WATERSHED Water Quantity: Surface Water The regional hydrology of the Shuswap River Watershed is influenced by the topographical and climatic characteristics of the area, which in turn determine annual runoff and surface water flows. The climate of this area is characterized by warm to hot summers and cold winters, with relatively dry conditions in the warmer valley bottoms of the Lower Shuswap River Watershed and much wetter and cooler conditions at higher elevations and particularly in the mountainous areas of the Upper Shuswap River Watershed. Freshet surface water flows in the Shuswap River begin in April with the melting of the lower elevation snowpack, increase in May as snowmelt moves to the higher elevations, then peak and start to decline in June with the completion of the melt. Flows decline rapidly in July and then diminish more slowly into fall and winter. January and February are generally the lowest flow months of the year. Tributary streams follow the same general flow pattern, although freshet peaks occur earlier in May in the lower elevation tributaries of the Middle and Lower Shuswap River Watershed. Annual surface runoff from the Upper Shuswap River exceeds 1000 mm/year, but diminishes to less than 200 mm/year in the lower elevations and drier conditions of the Lower Shuswap River. There are surface flow records for 34 Water Survey of Canada (WSC) hydrometric stations in the Shuswap River Watershed, which are used to characterize the annual, monthly, and daily flows of this area. The earliest flow records for the Shuswap River from the WSC station near Enderby date from 1911 so there is a long history of information available for this system. Unfortunately, considerable gaps exists in the hydrometric data available as only six of the stations are still active, only 14 have more than 10 years of flow records, there are no hydrometric stations upstream of the outlet of Sugar Lake, and there are no active stations in tributaries with unregulated flows. Re-establishment of several hydrometric stations on other tributaries with high water use (e.g., Fortune Creek) and several tributaries