A Desktop Method for Establishing Environmental Flows in Alberta Rivers and Streams
When humans decide to take water from the aquatic ecosystem for their own needs, determining how much water that must remain to meet the river's needs is a difficult and complex question. In Alberta, there are many instances where there is good hydrologic data but little to no biological data.
The Alberta government has developed a desktop method to determine environmental flows (instream flow needs) using readily available hydrology data. This method:
- assists Watershed Planning and Advisory Councils (WPACs) with the task of recommending environmental flow requirements in Alberta's rivers and streams where no site-specific environmental flow data exist
- is used by Alberta Environment and Parks in their consideration of issuing new water licences
The guideline is based on the latest scientific understanding of aquatic ecosystems and processes from site-specific instream flow needs studies carried out on rivers in the province and elsewhere.
The guideline is not designed to allow for detailed analysis of alternative flow regimes. It sets an environmental flow recommendation that provides for the full protection of the aquatic ecosystem.
- A Desktop Method for Establishing Environmental Flows in Alberta Rivers and Streams
- The Alberta Desktop Method for Determining Environmental Flows (Instream Flow Needs) – Fact sheet
Surface Water Allocation Directive
As of March 6, 2019, a new directive for surface water allocations has come into effect, supporting water allocation management decisions for watersheds without specific objectives or requirements under plans, frameworks or other prescriptive guidance.
The Surface Water Allocation Directive provides a desktop evaluation approach for consistent water allocation decision guidance to balance both ecological needs and economic considerations where planning processes have not established water management objectives. The directive provides guidance to water allocations from rivers, lakes and wetlands using a sustainable watershed approach. The directive applies to new water licence applications and temporary diversion licences and does not impact existing licences but may be applicable to term licences at time of renewal.
Further information on this change can be found at:
Lower Athabasca River Water Management Framework
The Surface Water Working Group of the Cumulative Environmental Management Association (CEMA) led a comprehensive multi-year effort to determine environmental flows and subsequently recommend a water management framework for the lower Athabasca River.
The Phase II CEMA committee's final water management framework recommendation reports:
The Highwood River Instream Flow Needs Study was the first of its kind carried out in Alberta to:
- have multi-stakeholder participation
- incorporate the higher or channel forming flows
- specify a comprehensive Ecosystem Base Flow (that is, a low flow below which any water withdrawals would not meet ecosystem objectives)
- be based on the natural flow regime
The environmental flow needs recommendation was based on the objective of providing a high level of protection for the Highwood River ecosystem and to meet the Fisheries Management Branch objectives for the Highwood River.
Lesser Slave Lake and River
Water Management Plan – Phase 1: Lesser Slave Lake and Lesser Slave River Basins
The Lesser Slave Lake Watershed Council has developed an interim Phase 1 water management plan for Lesser Slave Lake and River. To review the report for this project, visit the Lesser Slave Watershed Council website.
Water Management Plan – Phase 2: Lesser Slave Lake and Lesser Slave River Basins
The Phase 2 water management plan is to include input from the ongoing environmental flow studies on the river and water-level knowledge regarding the lake.
Public and stakeholder concerns regarding Lesser Slave Lake include:
- fish habitat quality
- high and low water levels
- lake eutrophication
- siltation and sediment infilling
The Instream Flow Needs Technical Advisory Team was charged with the task of developing a scope of work report to address lake level requirements for Lesser Slave Lake.
A number of recommendations that could be implemented as part of the management plan for lake water levels in Lesser Slave Lake are being considered by the Lesser Slave Lake Watershed Council. Similar to the river, a scope of work document was developed to understand water-level needs for Lesser Slave Lake.
Lesser Slave River Instream Flow Needs Scoping Study
The appointed Watershed Planning and Advisory Council for the Lesser Slave Lake and River watershed, the Lesser Slave Watershed Council, developed an instream flow needs scope of work report for the Lesser Slave River.
An Instream Flow Needs Technical Advisory Committee, struck by the Lesser Slave Watershed Council, was formed to develop an environmental flow recommendation that provides full, long-term protection to the aquatic ecosystem for the Lesser Slave River.
Based on the work plan, several field studies are underway or have been completed on the river including 2-dimensional hydraulic modelling and habitat analysis. It is expected development of the environmental flow recommendation will be a multi-year project.
To review the reports for this project, see the Lesser Slave River Hydraulic Surveying and 2D modelling section on the Lesser Slave Watershed Council website.
North Saskatchewan River
North Saskatchewan River Instream Flow Needs Scoping Study
The appointed WPAC for the North Saskatchewan River, the North Saskatchewan Watershed Alliance, developed a detailed instream flow needs scope of work report for the North Saskatchewan River.
The Fish and Wildlife Division of Sustainable Resource Development provided oversight for this study through its participation on the technical team.
To review the report for this study, visit the North Saskatchewan Watershed Alliance website at:
Red Deer River
Alberta Environment and Parks has developed a method for evaluating impacts to the aquatic environment for various flow scenarios on the Red Deer River.
The report outlines the methods and predicted environmental impacts.
- Aquatic Environment Impact Ratings, A Method for Evaluating SSRB Flow Scenarios: Red Deer River Case Study
South Saskatchewan River Basin
South Saskatchewan River Basin Study
The South Saskatchewan River Basin study examined a number of main stem reaches of the following waterbodies:
- Belly River
- Bow River
- Oldman River
- Red Deer River
- South Saskatchewan River proper
- St. Mary River
- Waterton River
The study looks at 4 components of the aquatic ecosystem:
- channel maintenance
- fish habitat
- riparian vegetation
- water quality
Based on hydrographic information (a graphical representation of the characteristics of the water such as flow, stage, velocity), the study analyzes:
- seasonal patterns and general changes in magnitude
- duration of the natural flow
These considerations are required to maintain intra-annual (within a year), and inter-annual (between years) changes of flow.
The intent of the study was to provide an environmental flows recommendation based on the objective to fully protect the aquatic ecosystem.
To review a report on the study, see South Saskatchewan River Basin water management plan.