from the Peace River, the Athabasca River and Lake Athabasca. 
The area remained in a pulse-stabilized early serai stage 
until the construction of the Bennett Dam in British Columbia 
which drastically reduced water levels in the Peace River 
during reservoir filling and, more important, cut off the 
peaks of the flow regime which previously had initiated 
floods. Rapid succession took place, adversely affecting 
habitat and food supply of waterfowl, bison, muskrat and 
many other species. Several remedial measures were attempted, 
although none have proved successful in restoring pre-Dam 
water regimes (Cordes and Pearce 1979, Townsend 1982). 
The study area chosen for this project is essentially the 
Athabasca portion of the Delta, the boundaries roughly para 
lleling the Embarras River, the Athabasca River and Fletcher 
Channel, all of which drain into Lake Athabasca. In 1974, 
water levels in the Delta were generally high due to large 
runoffs and the effect of a weir that had been built to an 
inappropriately high level. In 1978, the Delta continued to 
dry out, with little flooding. Two years of low water levels, 
no flooding and continued drought led up to 1980. 
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