Water Supply as a Limiting Factor for a New Town Proposed in the Bow ValleyIntroduction
Key Water IssuesThe most significant water-related issues for the development centre around water supply and wastewater removal. The ASP estimates the required amount of water to service the development to be 2400 m3 per day and approximately 1900 m3 per day would be returned to the river as treated effluent. To put these amounts in perspective, this community needs water that would fill up to 10 Olympic-sized swimming pools every day. The current water-related infrastructure (of Seebe townsite) is adequate for no more than 100 dwellings. Thus new water supply and wastewater infrastructure would be necessary as well as an expansion of water supply sources. Water supplyThere are two possible water sources for the development: the Bow River and groundwater from a deep aquifer near Exshaw. The developers have submitted two licence applications to withdraw water from the Bow River to Alberta Environment that would allow for 2800 m3 per day on average. These license applications are not subject to the recent moratorium on the Bow River. A decision on these licence applications is expected in mid-2007. To assure the developers are not putting themselves (and the new community!) at great risk by assuming there will be water available in every year, we strongly recommend that Alberta Environment conduct an evaluation analyzing to what extent this development will receive water in low water years given its junior license. Option B: Deep water aquiferThe developers' preferred choice of water source is withdrawal from Exshaw's deep aquifer, estimated to be about 650 metres deep. Alberta Environment (AENV) would approve this withdrawal because it is a non-saline source of water. Approval for aquifer use by this development should only occur following a broadly scoped (temporally, spatially, etc.), holistic, and science-based analysis that takes these concerns and new information into consideration. Regional water supply and wastewater systemIf approved, the aquifer would be expected to support up to 10 000 people in a regional supply system, which would include Exshaw, Horseshoe Lands, Greymont, Kananaskis Village, and Rafter Six, and the cement plant. This system would bring in high quality water that would require less expensive treatment than if the water were from the Bow River. This system would also bring in wastewater from these communities to be treated and released at the Horseshoe Lands site. The regional system could have positive net benefits for the region by removing existing systems (e.g., Kananaskis Village) that are having a negative impact on the environment and moving that wastewater through a better treatment facility. However, a regional system could increase the risk to aquatic ecosystems of the Bow River because the one outfall point of the system would increase impact intensity at one point, unlike multiple outfalls of multiple systems. The regional water supply system's creation would remove limitations for additional growth in the region proposed for the system and lead to more land development, more water pollution, and greater pressures on water resources than already proposed. A strong set of enforced criteria would be necessary to set boundaries for a regional system. The broad cumulative impact of such a system must be considered carefully. Alberta Environment should conduct a broad public assessment for such a system because the implications are more far reaching than this one development. Wastewater and stormwaterA town of 5000 people would put more wastewater effluent into the Bow River and generate polluted stormwater. The development's effect on water quality could be significant depending on the infrastructure built, types of sewer system and treatment, stormwater management, and controls on types of substances allowed into the system (e.g., prescription drugs, cleaners and chemicals used in residential and commercial venues, and petroleum and other mechanical substances released into the environment). Even if state of the art (tertiary) treatment is applied, there still can be a net negative impact to the river as treated effluent is still polluted water. Despite stormwater best management practices, stormwater could lead to contamination of the river, or groundwater contamination through retention ponds. Additional impact on this heavily used river should be carefully considered. A comprehensive plan should be developed before the Concept Plan. ConclusionThis development should not be approved beyond its current status of passed first reading without first ensuring it has access to a proven water supply and has approval for its wastewater system, whether onsite or regional. Current users and aquatic ecosystem integrity should take priority in deliberations of both the M.D. of Bighorn Council and Alberta Environment. Issues such as protection of riparian functionality and wetland integrity, and integration of conservation in design and water use should also take precedence in Council deliberations and demands for any future planning stages of the Horseshoe Lands development. Sources
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