Saunders Lake Area Structure Plan
March 14, 2017
Over the years the County of Leduc has completed master plans and studies to guide Council in effective planning and in the identification and preservation of environmentally sensitive areas.
In 2006 Leduc County commissioned the Parks & Open Spaces Master Plan. The following are direct quotations from this document.
· Priority for County Residents – Leduc County's primary focus in providing new parks will be to provide outdoor recreation facilities that meet the needs of residents of the County.
· Day Use Facilities – Outdoor recreation trends are changing the type of facilities requested in the County. New parks in the County will focus on providing more day use facilities for casual activities like walking, cycling, nature appreciation, dog walking and access to water for swimming, boating and fishing.
· Areas of Interest for New Parks, Saunders Lake – The County's Saunders Lake Area Structure Plan identifies Saunders Lake as a key recreational and environmental feature.
· Environmentally Sensitive Areas – Protection of sites identified as ESA's in the report Environmentally Sensitive Areas Study: Leduc County will be supported by Leduc County.
In 2008 Leduc County commissioned the Saunders Lake Parks and Open Space Concept Plan. The following are direct quotations from this document.
· Bank & Shoreline Stability –Saunders Lake is located in a glacial melt water channel with steep slopes that are considered highly susceptible to erosion (Spencer Environmental 2004), having high potential to lead to downslope sedimentation and lake infilling. Scheffer Andrew (2005) reports that the elevation of Saunders Lake is 690m, and the slopes rise up to 740m southwest and southeast of the lake. Development along the slopes to top of bank should be restricted and these slopes should be re-vegetated where possible. A leave strip is recommended along the top of the bank to prevent adverse impacts to Saunders Lake from erosion, as determined by geotechnical and wildlife considerations (Spencer Environmental 2004). The maximum possible width of this setback/buffer is recommended (e.g. 100-250m), given the friable soils and potential for species at risk habitat.
· Lake Characteristics & Water Quality – Saunders Lake is a very shallow lake (reports suggest maximum depth of 3-4m, but average depth likely closer to 1m) located in a watershed of rich soils. This suggests it could be very biologically productive, prone to high vegetation production and algal blooms. The shallow nature of the lake would make it more prone to mixing, high turbidity levels, and sedimentation.
· Waterfowl Habitat – Saunders Lake is considered Class 1 waterfowl habitat presenting a good opportunity for waterfowl viewing. Potential recreational uses related to this include viewing platforms, interpretative signage, viewing scope, and/or viewing boardwalk.
In 2015 Leduc County commissioned the Leduc County Environmentally Significant Areas Study; the Saunders Lake Area is noted as a High Risk (aquatic and riparian) Area. The following is a direct quote from the study.
· Aquatic and Riparian ESAs – Human activity that results in the disruption of hydrologic regimes through diversion or impoundment of surface or groundwater flows, as well as dredging or filling of streams, wetlands, and other water bodies, can severely impact Aquatic and Riparian ESAs not only in the immediate vicinity, but also downstream of the activity. Changes in water quantity and quality, as well the duration and frequency of hydrologic flows across the landscape, can also have significant impacts on the ecological health of terrestrial habitats in proximity to Aquatic and Riparian ESAs.
In summary, Saunders Lake has been identified as an environmentally sensitive area, vulnerable to the turbidity created at a stormwater outfall and the pollutants that will not be eliminated through settlement. Saunders Lake would be prone to algal bloom at an outfall where concentrated fertilizer runoff would enter the lake. Saunders Lake has been identified as a future park location, and in keeping with the growing popularity of walking, jogging and cycling could provide a first class nature trail to satisfy growing needs.
So the whole concept of a nature trail works better when there is watchable wildlife.
I asked the County if there were any technical reasons why the stormwater from the Saunders Lake development could not go directly into the Blackmud Creek drainage channel and avoid Saunders Lake altogether. They replied, and I quote, "A complete diversion of water from Saunders Lake would reduce the lake levels in Saunders Lake which could have unpleasant side effects. The controlled flow rates are to maintain predevelopment flow rates. The volume will be higher and as a result the duration of flow through Saunders Lake will be longer (as reduced by the "Bioswales" efforts). This will keep the water in Saunders Lake fresher. An Intermunicipal study is under way to ensure that the discharge rate be set to address the concerns of all municipalities contributing to the Blackmud Creek."
Now there are several things wrong with this view. First and foremost, I don't think that we can be concerned with reduced water levels in Saunders Lake when the land around Telford Lake continues to be developed and all the stormwater collected is drained from Telford Lake, through Saunders Lake into Blackmud Creek. You do not get fresh water from a stormwater collection system, and at the point of discharge the stormwater will have a high concentration of pollutants. Bioswales and constructed wetlands are definitely the way to go and the developer is to be applauded for moving in this direction, this will enhance groundwater recharge, improve water quality, moderate flood peaks and surges, increase water holding ability and increase a wildlife resource. At the same time helping to address discharge rates into Blackmud Creek. These measures should limit discharge to times after heavy rain when Saunders Lake would already be full and the stormwater would cause overflow into Blackmud Creek – again why is it important to dilute this polluted stormwater in Saunders Lake, before it runs into Blackmud Creek.
I also asked the County of Leduc why it was that the City of Leduc can require "Individual property owners to provide some level of on-site stormwater management to minimize the downstream storage requirements" and yet in the Saunders Lake ASP this is not allowed. I was told, and I quote, "Each municipality has the right to manage their community as they see fit. The approach of using on lot storage has a number of benefits and disadvantages. In Leduc County's case, the balance is in favour of using centralized Storm Water Management Facilities".
This response shows a poor understanding of on-site stormwater management, it is not about retention ponds. On-site stormwater management is rainwater harvesting for re-use, the use of porous paving, rain gardens, absorbent landscaping, bioretention areas, vegetated swales and green roofs. All of which reduce the amount of rainwater that is destined to become stormwater, and travel via bioswales to constructed wetlands. In many municipalities these measures are encouraged with financial incentives, as it is recognized that infrastructure upgrades and replacement is expensive and at some point our rivers and creeks will not be able to cope. These measures should be recognized, adopted and promoted throughout the County. Coincidently a forested landscape absorbs rainwater 67 times faster than hardened bare ground.
I might not have the opportunity to address Council again on this matter, so, I would like to close by recommending that the County pursue the provision of a rewilded, barrier free nature trail in a 30 metre wide reserve at the top of the escarpment and put in place measures that would prohibit the discharge of stormwater into Saunders Lake for this and all future developments, while encouraging on-site stormwater management on all developments throughout the County.
