This report provides a history and overview of the environmental flow work completed over a nine year period, 2000 to 2009, on the lower Athabasca River. The work is represented by 64 consultant study reports, 17 internal Instream Flow Needs Technical Task Group (IFNTTG) reports and five published scientific papers all of which are referenced in this report. Copies of the consultant and IFNTTG reports are provided in the Appendices and data files that accompany this report and many of them are on file in the Cumulative Environmental Management Association (CEMA) offices in Fort McMurray, Alberta, Canada. This report is in three main parts:

Part 1 provides a history of the IFN working groups that have employed technical knowledge and applied research to develop the tools to determine an environmental flow recommendation for the lower Athabasca River that will meet the stated objective:

Develop a defensible, science-based IFN recommendation that provides full, long-term protection to the aquatic ecosystem of the lower Athabasca River.

Part 2 of the report reviews the program of science taken to develop the tools to enable decision makers to analyze the response of the lower Athabasca River to a variety of water withdrawal scenarios that do not necessarily meet an objective of full protection. These environmental flow assessments were made to allow for an informed decision about water management on the lower Athabasca River (LAR).

Part 3 of the report translates the river science in Part 2 into Impact Hypotheses from which Evaluation Criteria could be developed. Many impact hypotheses were examined; some were retained, discarded, forwarded to other working groups or considered as potential monitoring indicators in a future monitoring program. Eight impact hypotheses resulted in evaluation criteria, decision tools for testing the responses of the aquatic ecosystem to various water withdrawal alternatives.

The final charge to the IFNTTG was to contribute to the development of a monitoring program for the LAR once a flow recommendation had been decided. IFNTTG held internal meetings and an external workshop to assist in development of a monitoring program and has transmitted recommendations to the P2FC.