Rainbow Ridge Environmental Update
The Cortes Housing Committee has enjoyed several productive discussions and meetings with Friends of Cortes Island (FOCI). The housing project team recognizes that Rainbow Ridge lies within the sensitive Gunflint and Hague Lake Watersheds; as FOCI has clearly demonstrated with their monitoring activities over the last few years, these Watersheds are stressed and are showing signs of excessive nutrient loading or eutrophication.
Throughout the housing project launch and public workshop last spring, representatives of FOCI were asking us important questions; we have met with them to discuss our approach and share ideas.
To that end, we thought it was important also to share with the Cortes public some of our progress so far, and to assure everyone that once the work identified below is complete we will provide further updates and information to the community.
Our environmental planning efforts are currently focused on the following strategies:
- Cluster the first phase of development (likely 20 units) in the northern portion of the property. This will allow us to:
- Retain more of the forest than might be the case with a more spread-out development pattern. As much as possible, we will retain existing forest areas dominated by conifers and preserve larger tracts of continuous forest, rather than fragmented patches.
- Retain wildlife corridors along the property boundaries, plus two mid-property corridors for east-west wildlife movement.
- Invest in a Type 2 on-site sewage treatment system to (a) eliminate possible pathogens and (b) strictly limit the amount of nutrients being released into our disposal field. The AdvanTex ® system we are considering is similar to the system recently installed at the Natural Food Co-op, and is significantly better at reducing nitrogen than typical septic systems installed on most residential properties.
- Restore a more natural hydrology pattern; we plan to reduce the volume of surface and groundwater presently being diverted into the Beasley Road ditch, which should reduce the nutrient load from Rainbow Ridge.
- Under the guidance of Ron McMurtrie, our consulting wastewater engineer, we will optimize the design and location of our septic disposal fields. In addition to planting them with beneficial species, we plan to place them within forested areas; trees and other plants downslope of our fields would then maximize uptake of any released nutrients. Ron has already completed a number of soil test pits, and his results are informing the site planning and design process. The distance from Hague Lake (420 m or more) means that any residual nutrients that might leach out of our septic system are unlikely to reach the lake.
To meet the objectives listed above, we are currently working to recruit a hydrogeologist/hydrologist/engineer to work with us on Rainbow Ridge to:
A: Prepare a hydrogeological report that evaluates the capacity of the groundwater aquifer to support the proposed density of development and associated water use for the Strathcona Regional District. This report is also required by the Vancouver Island Health Authority (VIHA) to identify and evaluate any existing risks to drinking water.
B: Assess the site’s existing hydrology and storm water regimen, then recommend ways to restore a more natural pattern and appropriate rainwater management program for the Phase 1 development, with three overarching goals:
- To avoid creating water issues for our downslope neighbours.
- To reduce nutrient flows to Hague Lake. This includes ensuring that our rainwater management strategies don’t direct nutrients from the new sewerage systems to the lake.
- To support the restoration of retained forest areas.
C: Develop a water quality monitoring program, aimed at a solid understanding of baseline nutrient levels for the on-site groundwater and surface water of Rainbow Ridge. Then in collaboration with FOCI, we would like to integrate this baseline information into a neighbourhood context by also analyzing surface water in the Beasley Road, Sutil Point Road, and possibly Bellwood Road ditches. Similar testing following the development of Phase 1 will tell us whether we have achieved our goal; if we have not, this will alert us to take mitigating action as necessary, to reduce the amount of nutrients reaching Hague Lake.
Once some of this work is complete and the monitoring program designed, we will hold a public meeting (early in 2019) dedicated to these specific environmental issues, and provide the community with updates and specific information.
We have the opportunity to achieve something exceptional: adding affordable housing for our community, while simultaneously reducing the impact on our most sensitive lake watershed.
We believe that by working together, we can achieve this, and that our story will become an example or model for the other communities dealing with similar issues.
Cordially, Elizabeth Anderson,
CISS Housing Committee Chair