The Credit River Valley
Credit at CulhamThe Credit River is nothing less than a "jewel" set in the heart of southern Ontario, Canada. It has two main sources, one out flowing from the headwaters around Orangeville, the other from Alton to the west and after joining together, meanders south to Lake Ontario, a distance of nearly sixty miles. It covers 1,070 kilometers with its mouth situated at Port Credit.

The Credit River Valley forms the northern limit of the Carolinian Forest Zone and as such is home to many species of flora not found in any other part of Canada. The Sasafrass Tree and the Tulip Tree are two examples. The Valley is strategically placed at the meeting point of the Oak Ridges Moraine and the Niagara Escarpment. It is an important source for Lake Ontario and a major migratory corridor from Lake Ontario to the interior of the province. It is a unique river in that it has a naturally producing native brook trout population.

Red Side Dace

Photo Courtesty of Todd D. Crail

The Credit Valley is home to 47 species at risk. Here live vulnerable species such as the Red Shouldered Hawk and the Yellow Breasted Chat. Provincially threatened species such as the Red Sided Dace(pictured right) flourish in the Credit. Nationally threatened species such as Jefferson’s Salamander, Least Bittern, Deep Water Sculpin and Henslows Sparrow make the Credit River Valley their home. As you can see, it’s a waterway of not only provincial significance but also national.

From an historical viewpoint, the Credit River Valley has experienced dynamic geological stresses, been part of important historical events and has been the subject of many environmental concerns in its 10 000 years. It is a river of contrasts – flowing from western Ontario uplands to the St. Lawrence lowlands, from quiet rural countryside to energetic urban centres near Lake Ontario. The Credit River has had a significant historical impact on all the communities that have sprung up along its valley for thousands of years. Its heritage reflects our heritage in so very many ways. Over those years, it has been a constant source of water, biodiversity, transportation, industry, food, recreation, and inspiration for countless generations of Southern Ontarians.

Credit River in winterThe Credit Valley came into being when western Ontario lifted into a broad dome known as a geoanticline, forming the valley on the eastern slope of the dome. The rise in altitude to the west becomes dramatic where the defining Niagara Escarpment passes through the watershed. The glaciers also left their unique stamp on the Valley. As they retreated, melt waters formed enormous rivers that run along spillways still in existence. The Credit River occupies a connected spillway system as far down as Glen Williams, which is met by the West Branch spillway.

Carrying enormous loads, the glaciers molded deposits known as kame moraines, easily identifiable in the rolling Caldwell Sandy H ills and the Orangeville Sandy Hills, where headwaters of the main branch of the Credit rise. Further south, in the Caledon Moraine, the deposit composition is coarser, but both types of moraine are characterized by verdant wet valleys that support abundant wildlife and unique biodiversity. The presence of all these moraines is especially fortunate for the watershed as it means that vast amounts of water can be absorbed into abundant underground coldwater aquifers. These pristine reservoirs of groundwater are essential to the existence and on-going health of the Credit and its communities.

Below the Escarpment the formation of the land took on a different dynamic. Influenced by glacial lakes and rivers, an area of broad, fertile plains were formed, known as the Peel Till Plains, the Shale Plain and the Port Credit Sandy Plain, interrupted only by the Streetsville Moraine, which is a gentle version of its northern cousins.

Credit River fallsIt is important to understand the geology of the watershed and how it affects not only the land’s ability to support substantial flora but also its direct affect upon climate.

In terms of climate, the watershed can be divided into three regions; the Lakeshore, the Peel Plain and the Uplands. The cooler, wetter weather occurs in the Uplands, a moderate range applies on the Peel Plain and a milder influence occurs toward the lake. Life in and along the Credit flourishes because of these two factors, geology and climate; factors that played an important role in early settlement and later in the region’s environmental challenges. We must improve the protection of the river system from encroachment of inappropriate industrial and urban development--too much of which can irrevocably damage the volume and flow of water in the watershed.

Cedar Waxing at CulhumToday, with a large and growing urban population, the Credit River system serves not only as the lungs of The Greater Toronto Area (GTA), but as an oasis where over a million people enjoy walks along its trails, appreciating nature and Ontario’s history. It is a local and provincial tourist attraction that boosts the economy and makes the whole area an attractive place to visit. The watershed is indispensable to the wellness of all its residents and provides important reservoirs of groundwater for the whole area. While impossible to quantify its value, there is no doubt that to residents of the GTA, it is priceless.

Sources of Information:

Credit River Valley, 1992, Stoddart Publishing Company Limited
Credit River Anglers Association Website
Credit River Alliance, Powerpoint Presentation – Ripples on the Water

Researched, written and submitted by Peter Orphanos Director, Credit River Alliance September 3, 2004