Natural shorelines protect water quality
Waterfront owners may not realize that the state of their shorelines directly affects water quality. Unfortunately, what happens on the land doesn’t stay on the land – at least not without a buffer zone of natural vegetation to help prevent excess nutrients and chemicals from getting into the lakes.
Deteriorating water quality is largely the result of too many nutrients, especially phosphorus, in lake water and sediments. On our lakes, most of this phosphorus comes from fertilizer and from septic systems leaching into the soil. So it’s important to stop the nutrients in runoff water and eroding soil from washing into the lake, where they “fertilize” algae and aquatic weeds and pollute the water. It’s equally important to prevent gas and oil and chemicals found in pesticides and herbicides from leaching into the water, because they are harmful to humans, fish and wildlife.
A simple, cost-effective way to help control runoff and erosion is to maintain or restore shorelines with a buffer zone of natural vegetation covering at least the first 15 metres back from the edge of the water. A variety of native species of vegetation – ground covers, wild flowers, shrubs and trees – with strong spreading root systems will slow down the rate of natural runoff and trap nutrients, pollutants and eroding soil before they reach the water.
Taller plants or bushes, rather than a lawn, also discourage geese from coming up on shore, because they love to feed on lawns, and believe predators may be lurking in taller vegetation. Native plants with strong root systems also help prevent shoreline erosion from wave action and boat wakes, and provide habitat for wildlife.
The lake wants a separation from your lawn
Waterfront owners should keep any lawn area at least 15 metres back from the water’s edge, and should avoid using fertilizer, pesticides or herbicides of any sort near the water.
Keep any lawn at least seven centimetres tall to slow down runoff. A lawn is a hard surface and rainwater runs off short lawn grass about twice as fast as off larger plants. A good beginning is to stop cutting the first three metres back from the water and watch as native plants begin to appear.
Wildlife depends on the ribbon of life
The first 10 to 15 metres of shoreland and the shallow water next to it are extremely important to wildlife, and are also key to water quality. Clear scientific evidence now exists showing how shorelines affect water quality, and how essential this riparian zone or ribbon of life is to the survival of almost all species, both in the water and on land.
Ninety per cent of all lake and river life depends on shoreline areas for birth, feeding and survival. Seventy per cent of land animals also depend on shorelines for survival at some point in their lives. Hardening shorelines with concrete shore walls or large stone blocks interrupts this ribbon of life and directly impacts wildlife, while doing little to prevent erosion over the long term.
To find out more about the importance of natural shorelines and how to naturalize yours, see:
Helping owners help their shorelines
In summer 2011, the Council helped sponsor and organize a Save Our Shores (SOS) workshop on Stoney Lake, presented by Lakeland Alliance and a number of environment professionals. Thanks to the workshop and the Council’s lake community outreach program, a number of waterfront owners signed up for free shoreline evaluations during the summers of 2011 and 2012.
Under this program, a professional consultant in shoreline ecology and management provides expert advice to lake residents on prevention of erosion, appropriate plantings and maintenance for their shorelines. The goal is to encourage more waterfront owners to naturalize their shorelines with buffer zones of vegetation, increasing wildlife habitat and protecting lake water quality.
For summer 2013, the Environment Council is offering 10 free on-site shoreline evaluations and recommendation reports by a professional shoreline restoration consultant. We are able to offer this program thanks to funding provided through a Toronto Zoo program.
To sign up for your free evaluation, go to “What’s New?” on our home page.