proposed artifical river ice damming to induce flooding of a delta ecosystem

Over the last twenty-five years, significant ecological changes have occurred in the Peace-Athabasca Delta largely because of changes in the hydrological regime of the Peace River, including flow regulation. Spring floods historically inundated the delta and supplied the major input to the water balance of many of the perched basins. No flooding of these basins, however, has occurred since 1974 despite historically high flows on the Peace River. As a result of long-term drying, there has been a significant reduction in wetlands and meadows and an invasion of more persistent shrub communities. Recent recognition that ice jams on the Peace River were the only way in which flooding of the perched basins could have occurred, a project has been initiated to flood these basins through the creation of artificial ice dams. An initial trial using surface-flooding was attempted in late-winter of 1993. Although the cover thickness was augmented no flooding occurred. Future plans are to employ spray-ice technology which should permit more rapid ice growth and a greater obstruction of the total flow depth.