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Pond and Stream Restoration

There are three major that cause the degradation of water quality in ponds and streams: lack of water circulation, proliferation of algae, and the accumulation of biomatter. Any one of these issues can be a major problem. Our approach is to address each problem separately in the following manner:

Water Circulation: Stagnant water, aside from being a breeding ground for mosquitoes, invites algal growth and traps biomatter that would otherwise normally wash through the pond system. Adding aeration systems such as diffusers will correct this issue and begin to restore normal patterns of circulation.

Algae: In a typical residential landscape, there are several thousand square feet of fertilizer-intensive turf areas which are rich in soluble minerals such as nitrogen and phosphate. In a rain storm, these minerals are washed off the lawn and into your pond or stream where they are immediately available to be used by algae. The solution to this problem is two-fold:

  1. Reduce the amount of lawn areas adjacent to the pond or stream, and plant a vegetated buffer to intercept any fertilizer-rich runoff. Selective use of approved wetland herbicides can kill off the grass without harming any of the fish, amphibian, insect, or bird species currently living in your pond. The dead grass areas may become a temporary eyesore, but their existing root system is vital to preventing harmful erosion of pond-edge soil while new plantings get established.

  2. Plant a vegetated pond buffer to reduce the amount of nitrogen-laden runoff entering your pond. These native, pond-loving plant species can filter moderate amounts of fertilizer-laden runoff that does flow towards the pond after they become established. The specialized emergent wetland species such as Blue Flag Iris (Iris versicolor) and Sweet Flag (Acorus americanus) that grow with their roots partially submerged in the pond will take care of the rest.

Biomatter Accumulation: Biomatter is a technical term for all of the leaves, twigs, branches, and other organic material that naturally enters your pond throughout the year and decomposes over time. Under normal circumstances, only a small layer will accumulate each season as the majority of the organic material will float or wash out of the pond to other watercourses downstream. In a pond without sufficient water circulation, biomatter is no longer able to exit the system and has no option but to build up. The accrual of extra material begins to reduce the volume available for water to move which only exacerbates the problem. There are several approaches to addressing this problem:

  1. One solution to this problem is dredging. However, it is a major undertaking considering the time involved in getting the permit, the expense of excavating and hauling, and the amount of disruption to your property.

  2. A more measured approach is to add a fore-bay to where water enters the pond. This man-made structure settles out biomatter as it enters the pond and provides a relatively small area to periodically clean. However, it does not address any organic material entering the pond from other sources such as the wind.

  3. Adding beneficial bacteria to the pond between April and October will accelerate the natural rate of decomposition and help reduce layers of biomatter in the pond. However, this process takes a considerable amount of time to see results. This strategy is best combined with other approaches to maximize its impact.

Stream Health: Streams offer a number of important ecological services for property owners. Dissipating floods, retaining water during droughts, and recharging underground aquifers are just a few of the most important ones. However, the continuation of these valuable services is dependent upon the stewardship of areas adjacent to the stream.

Streams that have been channelized or riprapped are no longer able to filter their water through adjacent floodplains during major storm events. As a result, the volume and velocity of the water increases, leading to erosion and scouring downstream. Keeping vegetation alongside streams not only prevents erosion issues, but it also creates habitat for local bird, fish, and insect species.

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