dams, or the reconstruction of old ones in the Ganaraska Authority at Garden 

 Hill, by the Holland Authority in Newmarket, by the South Nation Authority at 

 Casselman, by the Big Creek Region Authority at Simcoe. A complete list of 

 these community projects is included in a subsequent section of this report. 



Hydrometeorology 



Variations in meteorological conditions have a pronounced effect on the 

 flow pattern of the streams and rivers of Southern Ontario. Problems concern- 

 ing the relationship between meteorology and hydrology must be considered in 

 detail before controls can be established on a river. Hydrometeorological anal- 

 yses are therefore an important part of the water studies of this Branch. 



These analyses, which require data from an extensive network of precipita- 

 tion and stream gauge stations, relate rainfall, snowmelt and soil moisture con- 

 ditions to runoff in the streams. Such studies establish the characteristic of the 

 stream under a variety of meteorological conditions. The results are used to 

 establish the capacity of reservoirs, the size and type of dam structures or chan- 

 nel improvements and the availability of water for urban use, irrigation, pollu- 

 tion control, recreation and power supply. 



Besides giving attention to hydrometeorological analyses this Branch is also 

 concerned with research in the water balance of different regions of the Province. 

 To this end, the Conservation Authorities Branch, in co-operation with the 

 Upper Thames River Conservation Authority, has established at Fullarton, a 

 hydrologic research station. Certain instruments, which are set up at this small 

 station, aid in examining the rainfall runoff relationship on a small agricultural 

 watershed. - « 



Flood Warning 



The responsibility for flood warning in Ontario rests with the Hydro- 

 meteorological Section of the Conservation Authorities Branch. The need for 

 such a warning system was made abundantly clear following the devastation and 

 loss of life caused by Hurricane Hazel. 



A basic feature of the flood warning system is the close co-operation 

 between the Federal Government Department responsible for weather forecasts 

 and the Provincial Government Department responsible for river control. The 

 Meteorological Branch, Canada Department of Transport, is responsible for all 

 weather forecasting in Canada. That Branch, therefore, issues the necessary 

 weather data, weather forecasts and warnings of severe weather conditions, 

 while the Conservation Authorities Branch applies this weather information to 

 conditions existing on the watersheds and issues flood forecasts based on the re- 

 sults of the correlation of these two types of information. 



In 1955, the Meteorological Branch seconded a meteorologist to the Con- 

 servation Authorities Branch to head up the flood warning system. In this posi- 

 tion, which is designated as Hydrometeorologist, he is responsible for maintain- 

 ing a watch of river conditions, issuing flood forecasts, supervising the operation 

 of flood control reservoirs, and establishing meteorological design criteria for 

 river control structures. 



Ontario's flood warning system is at the present time unique in Canada. 



This system is designed to: 



1. Alert the general public to the danger of floods by indicating where 

 and when they will occur. 



2. Alert flood assistance agencies such as Emergency Measures Organiza- 



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