Many factors can affect the characteristics and development of surface water systems. For example, geographical characteristics such as topography, pre-existing moisture conditions in the soils, and hydrologic variability will all have a decided impact on how lakes and rivers are formed, as well as on their water retention capacity and flow rate. Other factors include land-use, regulations from control structures, and climatology. In fact, climate has a huge influence on the variability of water supply, with recent research focusing on measuring the flow within and between years.

In much of Ontario, for example, most flooding of rivers and streams comes following spring freshets, summer thunderstorms, or as a result of increased runoff in the fall. Also, both climate change and factors such as urbanization and population expansion can increase the already high losses experienced from floods.

Aqua Geomatics specializes in hydrologic analyses that measure the volumetric flow rate of water draining from a watershed over time. We begin by locating the exact location of the project site within the watershed, and then correctly estimate the flood flows and hydrographs for the 2, 5, 10, 25, 50, 100 and 1000-year return period floods, Regulatory Flood (RF), and Probable Maximum Flood (PMF). These are assessed both for standard rainfall events as well as for spring rain on snow.

Our models are based on the most recently available Environment Canada information available, covering rainfall intensity, duration and frequency for the area of interest. In addition, the methods we use are consistent with guidelines from both the OMNRF (2011) and the CDA (2007). We can prepare either new or existing models for your hydrologic assessment (HEC-HMS, OTTHYMO, SAARR, HEC-1 etc.)—whichever is best suited. The statistical floods generated by the hydrologic model are then compared with a regional flood frequency analysis of local stream flow stations to calibrate/verify the model results.

Our services include:

  • Terrain processing and classification
  • Basin and sub-watershed delineation
  • Reservoir shoreline delineation
  • Reservoir storage capacity and operating strategies
  • Rainfall-runoff analysis 
  • Watershed modeling and analysis
  • Flood frequency analysis based on gauged and historic data
  • PMP analysis and PMF estimation