The Athabasca River in Northern Alberta is facing ongoing petrochemical based industrial development on a colossal scale. Each of the many megaprojects in operation or under construction have a cumulative effect on the aquatic ecosystem in many ways with one key effect being a reduction in river discharge. Managing the use of this precious water resource can only happen by establishing causal relationships between the marginal withdrawal of water from the river and the quality of habitat available for use by aquatic ecosystem inhabitants.