Stormwater
Drainage is the natural or artificial removal of surface and sub-surface water from an area.
There are two primary systems for drainage that work separately:
- Stormwater system
- water from precipitation
- flows untreated into receiving water
- managed & maintained by engineering services
- Wastewater system
- liquid waste (sewage) from residential, commercial and industrial uses
- gets treated before returning to receiving water
- managed & maintained by Aquatera
The City of Grande Prairie's engineering services department maintains the storm sewers within the city, see Storm Water Services.
Stormwater is water from precipitation (rain, snow melt, etc.) that accumulates on the surface. As it flows, it collects and transports pollutants (soil, pet waste, salt, pesticides, fertilizer, oil and grease, leaves, litter, etc.). Stormwater is part of the water cycle.
A portion of the stormwater gets absorbed into the soil, which is called infiltration. The excess water that flows across a surface is called runoff. Impermeable surfaces (roofs, concrete, pavement, etc.) do not allow water to infiltrate into the soil and contributes to the amount of runoff.
Runoff enters into the storm system before finally flowing untreated into Bear Creek. This runoff will eventually make its way north to the Arctic Ocean.
Stormwater gets collected and transported through Grande Prairie's inter-connected storm system. It consists of:
- Open waterways, channels
- Ditches, grass swales
- Streets, gutters, concrete swales, catch basins, manholes
- Underground sewers
- Stormwater ponds
- Outfall structures
Historically, we tried to get rid of stormwater as quickly as possible. However, water is a resource that needs to be managed in a sustainable manner. Stormwater is managed for two main reasons:
- Volume - to prevent flooding
- Quality - to reduce pollutants and enhance the environment
Alberta Environment and Water has many programs and services that address our water.
- Legislation
- Water Act
- Environmental Protection & Enhancement Act
- Fisheries Act
- Protection
- Standards and guidelines (Best Management Practices)
- Performance assurance
- Knowledge and awareness
- Bylaws
- Lot Grading Bylaw C-1366
- Ensures each lot has positive drainage
- Water is not directed towards an adjacent parcel
- Drainage Bylaw C-1241
- Prohibits materials from being released into the storm system
- Prevents interference with the storm system
- Animal Control Bylaw C-1226
- Requires owners to dispose of animal waste in a sanitary manner
- Lot Grading Bylaw C-1366
- Planning
- City of Grande Prairie - Storm Drainage Master Plan, 2018
- Provides standards, guidelines and design criteria for new development
- Identifies requirements for new development
- Identifies required upgrades to the existing system
- Maintenance
- Street sweeping
- Catch basin cleaning
- Clearing debris from inlets
The best way to handle stormwater is to:
- Store it
- Spread it
- Sink it
Depending on your land-use, there are a variety of Best Management Practices (BMPs) that designers, engineers and landscapers can utilize to manage stormwater on your property. The BMPs are categorized as follows:
- Source control
- Lot level
- Conveyance
- End-of-pipe
- Low impact development
