The objective of this study is to examine the impact of regulating the Peace River in 1968 on the natural progradation of the Slave River Delta into Great Slave Lake. The report describes the hydrological relationship between the Peace and Slave Rivers both before and after impoundment. Changes in the flow regime of the Peace River that have occurred since impoundment and impacts of this change on the sediment transport regime of the Slave River are discussed. Implications of the altered sediment regime on the continued progradation of the Slave River Delta into Great Slave Lake are presented by examining change in the geomorphological and botanical dynamics of the Slave River Delta both before and after impoundment.