Meduxnekeag River Association
Red Bridge Gravel Pit Restoration
The Meduxnekeag river valley was formed over 12,000 years ago as the last glaciers retreated from the area. The resulting Meduxnekeag valley has extensive gravel deposits, particularly near Red Bridge and MacQuarrie Brook. The majority of the watershed is a fault-bound wedge of Ordovician sedimentary strata, which narrows as it approaches the Maine border. Rocks within the wedge are dominated by greywacke, slate and siltstone of the Tetagouche groups, and are calcareous. The calcareous base is the key contributing factor to the occurence of Appalachian Hardwood Forest sites along the Meduxnekeag River.
The geology and subsequently the soils of the Meduxnekeag valley have created a natural environment that over the past centuries has been melded into a mix of forests, agricultural lands and development, predominantly residential.
Since 2002 the Meduxnekeag River Association has been working to develop an understanding of the quality of the water in the Meduxnekeag River and its tributaries. The Meduxnekeag River Watershed Classification project determined that the water is generally of good quality. One of the identified concerns was the gravel pits and other developments that negatively contribute to water quality as a result of sedimentation, surface runoff and shoreline erosion.
As a result of the water classification project the Meduxnekeag River Association secured a 10-year licence of Occupation on a Crown (publicly owned) Gravel Pit (outlined in yellow) along the banks of the Meduxnekeag River at Red Bridge for the purposing of undertaking a gravel pit restoration project. This is a timely initiative given the amount of ongoing development and road building that is occurring in the area. As road building wraps up, more gravel pits will be abandoned.
The Crown gravel pit was formerly utilized by the Department of Transportation as a source of material for road construction and winter sand. In fact, a neighbour can remember hauling from the gravel pit for the construction of NB Hwy 95, when it was first built in 1972! Over the years the gravel pit was utilized less and less and began to show signs of naturalizing – the regeneration of trees and some grasses from the edge of the gravel pit towards the middle. This naturalization process was hindered by continual erosion and flooding as a result of Spring run-off from a culvert that crosses Route 540 and the sporadic removal of sand and gravel.
Before work could begin to assist the gravel pit in the naturalization process, the Meduxnekeag River Association needed to develop a restoration plan for the property. This consisted of outlining the work that would be undertaken at the site to mitigate erosion and sedimentation concerns along with the steps to assist in the naturalization process – what trees would be planted, how water from the culvert would be directed thru the site and so on. The first step in this process required the property to be surveyed and boundary lines blazed.
With a survey plan that delineates the contours (elevations) of the gravel pit as a basis, the next step was to develop a new contour plan that would eliminate surface runoff and erosion on the site. The new contour map is the basis for the restoration work at the site.
With the guidance of the new contour map site contouring began with the use of heavy equipment. As with most projects of this scale success is directly related to the individuals operating the machinery. For this project, we had Bernie (on the D7 bulldozer) and Doug (on the excavator) from E. Cummings Contracting of Woodstock doing all of the site recontouring.
Part of the restoration of the site involves the elimination of areas that contribute to erosion and sedimentation. One such site is where a drainage culvert crosses under Route 540 and enters onto the property. Over the years, runoff has eroded the bank beneath the culvert, creating the situation you can see in the picture.
Several steps were taken to rectify the erosion caused by the culvert and runoff, which predominantly occurred during heavy Spring rains. The first step was to remove the trees and brush so that the heavy equipment could access the site properly.
The next step involved resituating existing material to create a channel with as gentle a gradient as possible from the culvert to the holding pond below.
Once this was completed a layer of filter fabric was laid across the channel and rock was placed on top. The rock not only secures the fabric and soil in place, but also slows the water as it cascades down to the holding pond.
The finished channel is much more stable than before and now leads to a holding pond at the bottom, which further slows the water and allows the sediments to settle out and is a place for the water to seep into the ground. This is the point at which surface water begins the long journey to becoming ground water.
Another area of concern is the surface runoff created as a result of some of the larger flat areas in the gravel pit. These areas were recontoured to eliminate the large flat surfaces that pooled water and slowly eroded the nearby banks. Every effort was made during the recontouring of the site to keep the side slopes to less than 20% slope. This was accomplished in most areas, with a considerable portion of the slopes being less than 15% slope
Since the site contained very little organic matter, it was necessary to introduce some prior to planting any trees. The solution involved the spreading of organic compost that we sourced from Fox Brand in Woodstock. We employed the use of tractor and 10 tonne manure spreader to place the compost on the various slopes of the gravel pit. The organic compost will provide some much needed nutrients to the transplants and help begin the restoration process for the gravel pit.
The recontoured site is being planted with native trees – white birch, sugar maple, red maple, white ash, eastern hemlock, eastern white pine, red and white spruce, and eastern white cedar. This process will continue over the coming years and hopefully include some of the more tolerant hardwood species, the ones that are characteristic of Appalachian Hardwood Forests – basswood, butternut, ironwood and ash.
The gravel pit restoration project is ongoing. In the coming months an interpretive trail will be developed on the site, along with some signage which explains the gravel pit restoration process. In the Spring, a mix of natural wold flower and grass seeds will be scattered in suitable areas. Over the coming years we will continue to add native trees to the site, some shrubs and organic material. Eventually, the hope is that the site will resemble an Appalachian Hardwood Forest, similar to the Meduxnekeag Valley Nature Preserves.
The Meduxnekeag Valley Nature Preserve Red Bridge Gravel Pit Restoration project has been financed by the New Brunswick Environmental Trust Fund, New Brunswick Wildlife Trust Fund, The Meduxnekeag River Association and the by monies the organization received as a result of the Betco development at the Connell Road Walmart site.