Project Description

The first phase of the project was to remove some of the sand from Perry Monument. After passing the mandated state tests for disposal of dredge material, and in accordance with all applicable permits and regulations, approximately 917 m3 of material from the sand bar was dredged via a clam shell and placed in an unused gravel parking lot within the park so it could naturally dewater; the water could naturally seep through the gravel into the ground. The remaining sand bar was then graded to provide a suitable launch/ mooring area for canoes and shallow boats.

The next phase involved the creation of a stabilized area on the backside of Misery Bay where the multi purpose trail is located adjacent to an ecologically sensitive area of the park (an area where the natural habitat is to be maintained and little to no development is to occur). In this area, significant erosion had occurred, to the point that water was only 3-4.5 m from the trail.

Initially, the project proposed to install 10-25 cm sized riprap c. 7-9 m from the existing shoreline. However, based on design criteria for the worst case scenario for wave height, which in this area would be 1 m, the decision was made to place 30-61 cm sized riprap offshore; it was felt that this sized riprap would provide better protection for the shoreline. Placement of this riprap below the water line created an artificial stone shoreline that protected the multipurpose trail by func tioning as an erosion/wave energy dissipater.

Once the rock was in place, the third phase began. In this phase, the park placed the dewatered dredge material (sand) over the newly placed riprap, creating a higher elevation dune line. This subsequently provided a buffer of c. 8-9 m between the water and the trail. Next, to enhance the 'natural' appearance of the shoreline, ran domly spaced downed trees and stumps from the park (25-91 cm in diameter), minus the limbs, were used as timber groins. To function as groins, the tree root bases were anchored behind the riprap in the fill, and the trunks extended out past the riprap and into the water, also serving as sediment catch basins.

After the fill had been placed and prior to planting, the decision was made to use geotextile (comprised of coco nut fiber cured to aid in longevity) in conjunction with wattles (poles interwoven with slender branches) in order to augment the vegetative plant rooting and further sta bilize the dredged sand. The woven geotextile material is biodegradable, but it was anticipated that the plants should be well established before it decomposed.

Within the fill material, several trenches, parallel to the shoreline, were dug. First, the geotextile was laid in the trench, and then the wattles were placed on top - end to end and parallel to the shoreline, approximately at the average high water mark. The geotextile was then rolled back over the wattles and staked with live saplings. The wattles and geotextile were then further secured by pla cing sand on top; the sand helped to anchor the entire apparatus against the wind. The geotextile and wattles provided extra erosion protection to the shore zone area, as well as ensuring a stabilized area in the fine grained sand for plant rooting.

Prior to planting of the indigenous vegetation, plant community goals were established to ensure that the plants would thrive in the newly created environment. The plant community goals were developed by reviewing historical records of plant community structure in that area, consult ing local and regional plant experts, and considering wildlife uses of the site. After the goals were established, a vegetation planting plan was prepared. Final preparation of the site prior to planting included the addition of topsoil to the upper layer of sand, and shaping of the dune line.

The final phase was the vegetative planting. For this phase, local sources of plant material within the park were identified for transplanting onto the dune. These included beach grass (Ammophilia breviligulata), Indian sea oats (Chasmanthium latifolium), switch grass (Panicum virgatum), choke cherry (Prunus virginiana), bayberry (Myrica pensylvanica), and black oak (Quercus velutina). Additionally, driftwood from local sources was collected and was dispersed in the restored area to provide shelter for the young seedlings. Local sources of emergent wetland plants were located, and these were then transplanted into shallow water below the wattle trenches. Transplanted aquatic plants included species that enhanced the establish ment of desirable native emergent communities. These species, such as branching bur reed (Sparganiuma androcla dum), duckweed (Spirodela oligorrhiza), and soft stem bulrush (Scirpus validus) were also beneficial to waterfowl by providing a native food source.

After the native species were established, invasive species, such as purple loosestrife (Lythrum salicaria) and common reed (Phragmites australis), targeted in the Presque Isle Partnership report, were mechanically removed as they were encountered throughout the restored areas. Roundup, a glyphosate, was applied as necessary to eliminate invasive species that could not be controlled by mechanical means. The final objective was to achieve at least 50% vegetative cover in both the shoreline and dune habitats - this goal had been achieved within 6 months of project completion. Annual plane surveys have shown that since project completion, erosion has been reduced by approximately 90%, thus providing protection for the heavily used multipurpose trail.

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Homeowners Guide To Landscaping

Homeowners Guide To Landscaping

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