Flood Plain Study
In May 2016, R.M. Administration recommended that Council undertake a two-dimensional (2D) hydraulic modelling and mapping study of the South Saskatchewan River flood plain to determine what areas of the flood plain are floodway (no or limited development allowed) and flood fringe (development may be allowed subject to conditions); a map of the study area can be found HERE. At the August 21, 2017 Council meeting a motion was passed that the R.M. will pay 100% of the costs of the study under the condition that 50% will be reimbursed through grant funds.
The R.M. has successfully applied for funding under the National Disaster Mitigation Program – Stream 2: Flood Mapping, administered by Public Safety Canada. The federal government will pay for 50% of the project costs and the R.M. will be responsible for the other 50%. In December 2018, the R.M. and provincial government through the Flood Damage Reduction Program entered into an agreement for the province to pay the R.M.'s other 50% of the project costs.
A Request for Proposals (RFP) for the preparation of the study was released on January 16, 2018. The deadline for receipt of proposals was February 12, 2018; thirteen (13) proposals were received. On April 16, 2018 Barr Engineering was selected by R.M. Council as the consultant for the study. The R.M. has formed a Technical Committee comprising of R.M. Administration, Water Security Agency and Community Planning representatives to provide guidance to the consultant and review technical data and models. The consultant will be providing an in person summary presentation to R.M. Council at the conclusion of the study. After the study has concluded the final mapping and report will be made public. The study is expected to be completed by April 2019.
Phase 1: Data Confirmation & Field Survey (April – June 2018)
This phase includes review of available background information including statutory documents, data and related studies prior to development of the 2D model. Following a review of the data to identify any gaps, a field survey would be completed to complete the data acquisition. This includes a hydrographic survey of the river as well as ground survey of culverts and other infrastructure.
Phase 2: Hydraulic Modelling & Assessment (May – September 2018)
During this phase of the project the terrain dataset would be developed, the model parameters would be defined, and model calibration, validation and sensitivity analysis would occur. This step is crucial to ensuring a successful outcome for the study. Following these steps the model would be ran to stimulate the regulatory flood event (1:500) in addition to three smaller events (1:50, 1:100, and 1:200). The effect of full residential development (i.e. 5 per ¼) would also be considered as part of a modelling exercise for the 1:500.
Phase 3: Mapping Support & Flood Mapping Report (September 2018 – March 2019)
These final phases of the study involve completing GIS maps illustrating the flood plain, floodway and flood fringe. A written report will also be completed by the consultant to document data collection, the modelling assessment, flood mapping methodology and development of the flood plain maps.
For more information on the flood plain study please contact the R.M. project manager, Vicky Reaney at email@example.com or 306-975-1663.