Description

A new culvert installation on a stream tributary to the Bow River needed to be constructed.  In order to protect fish spawning areas the three day delay, 1 in 10 year (3Q10) flow between March 23 and April 7 needed to be determined.  Inadequate measured data was available to complete this analysis.  

The 3Q10 was determined by creating a storm water simulation model of the entire catchment area.  Climate data such as rainfall and temperature from a local meteorlogical station was used to provide inputs into the model.   Climate data from 1950 to 2006 was available.

Lidar elevation data was imported into a geographic information system.  The elevation data was filled then used to deternine catchment areas and drainage routes.  

A storm water simulation model used this information to sinulate the effects of rainfall and temperature and to determine flow rates during the period of interest at the Running Rabbit culvert location.  

Based on the results the 3 day delay flow was determined. A statistical analysis was used to determine the 10 year return period.