TABLE OF CONTENTS

• Disclaimer
• Summary
• Figure Map of the Salmon River Watershed
• Tables
  • Table 1. Water Quality Objectives for the Salmon River Watershed
  • Table 2. Average 30-day concentrations of total ammonia nitrogen for protection of freshwater aquatic life
  • Table 3. Recommended Water Quality Monitoring Program in the Salmon River Watershed
• Preface
• Introduction
• Hydrology
• Water Use
• Waste Water Discharges
• Water Quality Assessment
• Water Quality Objectives
• Water Quality Monitoring
• References
• Glossary

SUMMARY

The Salmon River is an important tributary of Shuswap Lake, which drains into the South Thompson River. In addition to supporting anadromous salmonids, resident fish species and other aquatic organisms, the Salmon River and its tributaries provide important sources of raw water for domestic water supplies, irrigation, and livestock watering. Recreation and aesthetics also represent important uses of the aquatic environment, both of which generate social and economic benefits to area residents.

Concerns related to environmental quality conditions in the Salmon River are primarily associated with non-point source contaminant discharges. Such contaminants arise from a variety of land use activities, including forest management, agriculture and urban development. Contaminants of concern in the watershed include suspended solids, turbidity, ammonia, phosphorus, nitrogen, metals and fecal coliforms. In addition, water withdrawals from the river and nearby infiltration galleries have resulted in decreased streamflows and associated effects on water temperatures and other habitat features in the river.

This report describes the water quality objectives that have been recommended for the Salmon River watershed. These objectives specify the water quality conditions that are necessary to protect aquatic life, wildlife, livestock watering, irrigation, drinking water supplies and aesthetic and recreational water uses in this river system. The objectives also represent targets which can be used to determine whether remediation efforts have been successful.

PREFACE

Water quality objectives are being jointly prepared by Environment Canada and the Ministry of Environment, Lands, and Parks, as part of their respective mandates for responsible water resource management. Objectives are prepared only for those waterbodies and water quality characteristics that may be affected by human activity, either now or in the future.

Water quality objectives are numerical concentrations or narrative statements which have been established to support and protect the most sensitive designated use of water at a specified site (BCMOELP 1986; CCREM 1987). They are derived from the guidelines and criteria by considering local water quality, water uses, water movement, waste discharges and other factors.

Water quality objectives are based on the best scientific information available at the time the objectives are developed. When insufficient information exists, provisional water quality objectives may be applied until the data required to develop permanent water quality objectives are available. Provisional objectives are deliberately conservative. To facilitate the establishment of permanent objectives, a monitoring or study program is usually recommended to fill any data gaps that are identified.

Water quality objectives are set to protect the most sensitive designated water use at a specific location. Designated uses of water include the following:

• raw drinking water, public water supply, and food processing;
• fish, other aquatic life, and wildlife;
• agriculture (livestock watering and irrigation);
• recreation and aesthetics; and,
• industrial water supplies.

Each objective for a location may be based on the protection of a different water use, depending on the uses that are most sensitive to the physical, chemical, or biological characteristics affecting that waterbody.

Water quality objectives are important water management tools because they provide policy direction for resource managers with respect to the protection of water uses in specific waterbodies. Objectives provide benchmarks for evaluating water quality, issuing wastewater discharge permits, dispersing water withdrawal licences and orders, and managing fisheries and the province's land base. They also provide reference points against which the state of water quality can be checked and help to determine whether additional management actions are needed to protect and/or restore the designated water uses in a particular waterbody.

INTRODUCTION

The Salmon River watershed is located within the Interior Plateau of south-central British Columbia. Its headwaters originate in the vicinity of Tahaetkun and Bouleau Mountains, south of Westwold and northeast of Merritt. The river's headwaters are located in Monte Hills Provincial Forest, some 15 km northeast from Salmon Lake. Some of the river's flow is diverted into Salmon Lake; much of that flow returns to the river via McInnis Creek, the outlet from Salmon Lake. From the confluence with McInnis Creek, the Salmon River flows northeast to Falkland, then southeast and east to Glenemma, and finally north to Salmon Arm of Shuswap Lake. The total length and drainage area of the Salmon River are approximately 120 km and 1510 km², respectively.

Profile of the Salmon River Watershed

HYDROLOGY

Low flows in the Salmon River and its tributaries generally occur through the fall and winter months and are influenced significantly by linkages with ground water. As such, inputs of ground water maintain streamflows in many portions of the watershed during periods of low precipitation. This situation is reversed in the vicinity of Westwold. At this location, the Salmon River flows below the surface for most of the year, creating a dry reach for a distance of about 13 km. While year-round above ground flows have been observed in this reach, this section of the river usually represents a barrier to upstream fish passage.

Water withdrawals for irrigation and domestic water supplies have a pronounced influence on the hydrology of the Salmon River watershed. It has been estimated that 30 to 50% of the historic flow has been diverted from the Salmon River to support these uses. These water withdrawals have the potential to significantly influence both the quality and quantity of aquatic habitats in the river, with associated effects on fish and aquatic organisms. For this reason, water quantity objectives are also needed for the Salmon River and its tributaries.

WATER USE

There are both consumptive and non-consumptive water uses within the study area. Consumptive water uses include withdrawals of raw water for domestic water supplies, irrigation, and livestock watering. Non-consumptive water uses include instream uses by fish and aquatic life, and recreation and aesthetics. The Salmon River and its tributaries provide habitats for a number of important sportfish species, including chinook salmon, coho salmon, sockeye salmon, rainbow trout and mountain whitefish. Aquatic habitats within the watershed also support a variety of resident fish species, aquatic invertebrates, amphibians, reptiles, birds, and mammals. The river is also becoming increasingly important for recreational water uses, including swimming, canoeing and bird watching.

WASTE WATER DISCHARGES

There are no permitted wastewater discharges to the Salmon River or its tributaries. However, there are a number of indirect (i.e., non-point source) effluent discharges to tile fields, which have the potential to influence water quality conditions in the river. In addition, there are numerous other non-point or diffuse sources of environmental contaminants in the basin, including those originating from agricultural activities, forest management, urbanization, linear developments and limited mineral extraction. Priority substances associated with these contaminant sources include suspended solids, turbidity, ammonia and other forms of nitrogen, phosphorus, metals and fecal coliforms.

Water Quality Assessment and Objectives

WATER QUALITY ASSESSMENT

Water quality concerns in the Salmon River are not limited to accelerated sediment transport and sedimentation. Elevated levels of nutrients (i.e., total phosphorus, total ammonia), certain metals (i.e., total arsenic, total cadmium, total chromium, total copper, total lead, total mercury and total zinc) and microbial indicators (i.e., fecal coliforms) have also been observed at several locations in the basin. During the summer months, water temperatures approach or exceed the levels that are known to adversely affect salmonid fishes, particularly near the mouth of the river.

While water quality conditions are generally similar among the locations that have been sampled in the Salmon River watershed, some important trends are evident from the available data. For example, pH generally increases from the headwaters to the mouth of the river. This is not uncommon in BC since the headwaters of streams often have little buffering potential; however, both buffering potential and pH tend to increase along the lengths of BC streams.

Similarly, concentrations of suspended solids increase along the length of the river, presumably due to general erosion and inputs from non-point sources on the mainstem and in the tributaries. The levels of fecal coliforms also follow this same general pattern. However, the concentrations of ammonia and total phosphorus are highest in the vicinity of Bolean Creek, likely reflecting inputs from the cattle feed lots that are prevalent in this area.

Information on trends over time provide a basis for determining if water quality is improving, worsening, or remaining the same. Recently, two focussed studies were conducted to evaluate water quality conditions in the Salmon River. The results of both of these studies indicated that water quality conditions are not showing any environmentally significant long-term trends (Lilley and Webber 1997; Regnier and Shaw 1997).

Water quality conditions are also degraded in Tappen Bay, which is located near the mouth of the Salmon River. At this location, elevated levels of total and ortho-phosphorus have been observed, particularly during the spring and summer months. High phosphorus levels represent a significant environmental concern in lakes because they can stimulate algal growth, which can represent an aesthetic concern (i.e., due to reduced water clarity) and a threat to aquatic life (i.e., due to reduced dissolved oxygen levels). The phosphorus in the bay originates largely from the Salmon River and the Salmon Arm sewage treatment plant. High levels of fecal coliforms may also be adversely affecting certain water uses in the bay (e.g., swimming) during portions of the year. Together, these data show that improvements in water quality conditions are needed to maintain existing water uses and support fisheries restoration efforts in the watershed.

WATER QUALITY OBJECTIVES

The water quality objectives for the Salmon River are presented in Table 1 and Table 2. These objectives are based on the BC approved and working water quality criteria (Nagpal et al. 1995), the Canadian water quality guidelines (CCREM 1987), and the available data on ambient water quality conditions, water uses and streamflows in the Salmon River watershed. The BC approved and working water quality criteria and/or the Canadian water quality guidelines are considered to apply to those variables for which site-specific water quality objectives have not been specified.

The water quality objectives for many of the priority substances identified are currently being met throughout much of the year in the Salmon River watershed. Where these objectives are not being met presently, they represent targets which should be used to identify priorities for future investigations, management actions, and remedial measures to improve water quality conditions.

MONITORING RECOMMENDATIONS

Monitoring programs should be designed and coordinated to determine the degree to which the water quality objectives are being met within the waterbody under investigation. Exceedances of the objectives indicate that one or more of the designated water uses may be threatened. Monitoring ecosystem responses to environmental disturbances provides a direct means of identifying situations where specific management actions or more restrictive water quality objectives are needed to meet water management goals. A recommended monitoring program design for the Salmon River and Tappen Bay is presented in Table 3. The recommended monitoring program specifies the locations, sampling timing, and sampling frequency needed to determine if the water quality objectives are currently being met. As there are various other monitoring programs being conducted in the watershed, it would be reasonable to integrate the recommended monitoring program into existing programs to achieve cost saving, prevent the perception of "duplication", and assure the comparability of the resultant data. Actual monitoring undertaken will depend upon resources available to BC Ministry of Environment, Lands, and Parks, Environment Canada, and local stewardship groups empowered to undertake such monitoring.

REFERENCES

• BCMOELP (British Columbia Ministry of Environment, Lands, and Parks). 1986. Principles for preparing water quality objectives in British Columbia. Water Management Branch. Victoria, British Columbia. 20pp.
• CCREM (Canadian Council of Resource and Environment Ministers). 1987. Canadian water quality guidelines. Task Force on Water Quality Guidelines. Ottawa, Canada.
• Gwanikar, S., S. Cross, D. MacDonald, J. R. Brown, D. Q. Tao, and T. Berger. 1997. Salmon River: Water quality assessment and Recommended objectives. Technical Appendix. Prepared for Environment Canada. Vancouver, British Columbia. Prepared by Aquametrix Research Ltd. and MacDonald Environmental Sciences Ltd.
• Lilley, L. G. and T. N. Webber. 1997. State of water quality of Salmon River at Salmon Arm, 1985-1995, Canada-British Columbia water quality monitoring agreement. British Columbia Ministry of Environment, Lands and Parks. Victoria, British Columbia.
• Nagpal, N. K., L. W. Pommen, and L. G. Swain. 1995. Approved and working criteria for water quality. Waste Management Division. Water Quality Branch. British Columbia Ministry of Environment, Lands, and Parks. Victoria, British Columbia.
• Regnier, R. and D. P. Shaw. 1997. Water quality trends in the Fraser River basin, 1985-1996. Environment Canada, Fraser River Action Plan. FRAP 1997-draft.

WATER QUALITY OBJECTIVES AND MONITORING TABLES

Some readers may be unfamiliar with terms such as: maximum concentration, 30-day average concentration, 90th percentile, and not applicable (NA). A maximum concentration refers to the value for a specific variable that should never be exceeded. A 30-day average concentration defines the level that should not be exceeded by the average value calculated for five or more samples that are collected at approximately equal intervals during a period of 30 days. The term 90th percentile indicates that 9 out of 10 values should be less than a particular value. Not applicable means that water uses are not threatened for that particular variable.

Table 1. Water Quality Objectives for the Salmon River Watershed.