Risk of overland flooding always a concern in county

By Nikki Jamieson
Sunny South News

With the amount of rain lately, it’s not unusual to see a flooded ditch. However, too much rainfall can lead to more than just the ditches flooding.

“Weather and overland drainage is a regional concern and Lethbridge County and its local partners actively work on addressing these concerns. Nature can present unknowns that we can not control and weather is the largest challenge we face on a daily basis,” said Jeremy Wickson, director of public operations for Lethbridge County.

Unlike floods, which typically refers to coastal flooding events, overland flooding is when bodies of fresh water overflow onto dry land, and is typically caused by two different events; rainfall or snowmelt, which present different challenges in terms of preparation and damages.

The county uses an emergency-based response to overland flooding events, where they are concerned with, in order, the risk to life, property and land.

Excessive water running by property and significant pooling in areas of potential risk is the biggest sign of an overland flooding event. Those areas will have a history of flooding, and due to the large landscape of the county, Wickson says local residents are their best resources for identifying these areas of concern.

The time of year will also affect the length of the event. In summer, water will soak into the ground progressively. In the spring, however, if the ground is still frozen, it will flow over the frozen surface and pose a greater risk to the county’s residents.

Overland flooding will also impact a hamlet differently than a more rural residence, as hamlet infrastructure often includes storm drains through catch basins that go underground to discharge points, and well as master drainage plans, where water goes to outfall areas outside of town, so during an event, the streets will flow heavily and the water will travel to these catchments.

“The other consideration is the area or acres of impact. A hamlet has a smaller footprint of potential water catchment as they cover an area not as large as a quarter section or 160 acres. Overland drainage on farmland often is multiple quarter sections that are draining, in addition to the irrigation quarters which are already saturated from irrigation farming activities, at which point the ground can only retain so much moisture.”

Flooded roads also cause a significant concern for the county, as even if you know the area well, you can’t tell what you are driving on.

“If a road is flooded over, call the county immediately and report the location by legal address or Range Road or Township Road number, be specific as to the location. When roads flood the shoulders and interior of the driving surface erode or have a significant failure that could cause an accident. Drivers should not drive through flooded roads as they can not see what condition it is in,” said Wickson.

“Upon notification the \county will dispatch crews to install warning signage, barricades and other warning devices as required.”

The county is engaged in addressing ongoing regional drainage and evaluations of catchment basins, and has water studies on the Battersea, 8 Mile Lake and Tiffin areas, in order to identify and plan for future drainage planning. They have a framework agreement in place with two local irrigation districts, St. Mary and Lethbridge Northern, to share in regional drainage projects. The county also has a projects crew that mainly focuses on culvert installations through road allowances and addressing minor drainage issues.

If overland flooding occurs in your area, contact Alberta Environment Hotline (1-800-222-6514), Alberta Transportation – Volker Stevin (1-888-VSROADS) and Lethbridge County for issues within the road allowance (403-328-5525).

Get More Sunny South News →