Influence of Hydropower Peaking on Invertebrate Drift : Magpie River, Wawa, Ontario

Researchers:  Karen Smokorowski and Nick Jones

Project Description: The "ecological integrity" of flowing waters depends on their natural flow regime. Deviations from a natural flow regime may result in new constraints on community structure of invertebrates and loss of productive fish habitat. This study examines the response of invertebrate drift to abrupt changes in discharge releases downstream of the Steephill Dam on the Magpie River, Wawa, Ontario. The Magpie River is regulated to a limited ramping rate of ~1 m3s-1 with a minimum flow of 7.5 and a maximum generating flow of 45 cms. This flow regime results in a variable wetted perimeter with a frequency and duration wetting set by market energy prices.

Project Objectives

Sample invertebrates in the drift during low flow, up ramping, high flow and down ramping on the Magpie River to determine if flow magnitude and change in flow impacts drift e.g., invertebrate density, diversity, organic matter and debris. 

Determine if the effect of flow change on drift is attenuated as a function of distance downstream of the dam.

Compare results on the Magpie River to a similar dirunal and spatial range on the Batchawana River.

Collaborators and Participants:
Brookfield Power

Links: Indicators of Hydrologic Alteration, The Natural Flow Regime

Interesting Facts: Streamflow quantity and timing, which is strongly correlated with many critical physicochemical characteristics of rivers, such as water temperature, channel geomorphology, and habitat diversity, can be considered a “master variable” that limits the distribution and abundance of riverine species and regulates the ecological integrity of flowing water systems.