Ice and River Control

Major problems in ice control were encountered at both the St. Lawrence and Niagara Rivers when full hydroelectric development took place. Extensive ice-control measures have been undertaken at both rivers which have proven to be most successful. At the St. Lawrence, channel enlargements were used to induce a stable ice cover by packing, and ice booms were provided to form and retain ice covers in unstable areas. At Niagara, a major improvement resulted from the construction of an ice boom in Lake Erie at the outlet to the Niagara River. The ice problem, at both rivers is described in detail as is the concept and bases of design of the ice-control measures. Of particular interest is the design of the ice booms, where if excessive loading occurs, the boom will submerge and allow some ice to pass, thus obviating the need to design for maximum ice pressures. Experience to date appears to confirm the validity of the design criteria.