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02-19-21 | Feature

Lagoon Creates New Habitats and Flood Resilience

New Life and Recreation From Lagoon Design
by Kenneth B Simmons, Jr., FASLA, KBSA - Landscape Architecture & Planning

The Camden, South Carolina Lagoon is an abandoned sewage pond redesigned to absorb flooding during harser weather while providing recreational opportunities in the more favorable times of the year. For this reason, the water level can be controlled through a water pump at the left corner leading into the site along with an agri-drain that determines when the water pump needs to be activated. To assist with wildlife and education purposes, two drainage impoundments were designed in the lagoon to create a controlled area that could be planted and flooded to grow crops like indigo and rice and attract waterfowl.
The Camden, South Carolina Lagoon is an abandoned sewage pond redesigned to absorb flooding during harser weather while providing recreational opportunities in the more favorable times of the year. For this reason, the water level can be controlled through a water pump at the left corner leading into the site along with an agri-drain that determines when the water pump needs to be activated. To assist with wildlife and education purposes, two drainage impoundments were designed in the lagoon to create a controlled area that could be planted and flooded to grow crops like indigo and rice and attract waterfowl.
A built-in kayak/canoe ramp was implemented into the boat ramp as well as handrails to create an easy way for rafters to safely get their boats from the parking lot to the river.
The photo shown exhibits current new growth and the habitat of the lagoon, about a year after completion. Natural plant species are starting to take growth along the walking trails and water's edge, creating a natural ecosystem buffer between wildlife and people visiting the park. Kayakers are now able to get the complete experience of rafting through the curving waters and observeing wildlife.
More than 80,000 cubic yards of dirt was moved during the construction of this project. The lagoon was carefully graded and excavated to use the dirt on site and minimize the amount of soil removed. Walking paths and large berms were designed to create enough leeway to construct a lagoon with different depths to support and promote a flourishing ecosystem.
An important factor in designing the lagoon for wildlife was studying the depths of water in different areas. The elevations of the lagoon range from four feet below the water's surface to 22 feet high on the islands. The goal of the project having a variety of water levels and island elevations was to allow for a range of different aquatic, plant, and other species to flourish in the available depth areas. For example, certain species of birds appreciate lower water levels than others as insects often prefer dwell at those levels. Different species of plants need different amounts of light and depths of water in order to grow. This also affects the types of birds and fish that inhabit the area. Having a large variation of depths throughout the lagoon increases the variety of waterfowl seen throughout the park.
The site shown, was an existing sewer treatment facility that was closed in 2015. This led to the creativity of revamping the area into a useful site that allowed for flood resistance and improved recreation opportunities.
About a month after project completion, an abundance of rain caused the river to overflow and flood the site. The water engulfed site demonstrated the resilience of the design. The water produced little damage and actually introduced new species of plants, fish, amphibians and insects to the successful renovation.

The City of Camden, SC is one of the oldest inland cities in the state, it was established on the banks of the Wateree River in 1732. As Camden grew it developed inward away from the river with public utilities becoming the major uses of the riverfront. Several years ago, the existing Camden sewerage treatment plant settlement pond was abandoned. Leaving a 16.5-acre rectangular, flat bottomed treatment pond. As this pond sat as an empty eyesore, the city investigated potential uses. Staff requesting input from civil engineering firms as well as a preliminary concept from the National Park Service.

Having worked with Kenneth B Simmons Associates (KBSA), a Landscape Architecture firm from Columbia, SC, on several other projects, the city requested this firm to provide an alternate solution to include river canoe/kayak and Emergency Medical Services (EMS) rescue access as well as an affordable recreation amenity. The KBSA's solution proposed a sculptured pond with multiple water depths to encourage various plant and animal habitat communities as well as a deeper winding waterway for canoeing and kayaking. This environmental project included five water control structures to effectively control the water levels at various river elevations and weather conditions. This design included two separate ponds within the site to allow for agriculture experimentation and education of water loving indigo and rice crops which contributed heavily to the history of this area.

KBSA, being the prime consultant, took the responsibility of creating a master plan, cost estimate, bid documents, and construction administration. Step-by-step, the KBSA team developed plans to transform this site. The lagoon, which was originally one of two used by the city's wastewater treatment plant, is approximately 25 feet in elevation above the Wateree River, whereas the interior of the lagoon basin is only 11 feet above the river. The first step in the master plan depicts grading the existing riverbank down ten feet to eliminate the amount of boat ramp required to meet the slope requirements of the American with Disabilities Act. By grading the riverbank down ten feet, 250 feet of ramp can be eliminated. Immediately adjacent to the boat ramp is a staging area and emergency vehicle turnaround. The dirt moved by re-sloping the riverbank is used to "soften" the edges of the rectangular lagoon so that it looks more natural.

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The next step was to dig out the bottom of the lagoon's interior in order to create a varied topography where lower elevations would be filled with water and higher elevations would become islands surrounded by shallow wetlands in order to create different "vegetative communities." Water levels vary from six inches of water, to three or four feet deep. A well was installed as the primary water source, which cascades over a waterfall down into the lagoon. Walking trails, boardwalks, and observation areas were then installed, and the trail will eventually link to the Camden's downtown area.

Lastly, was the construction of a floating environmental center, which houses restrooms, event space, and interpretive/educational classrooms all at water level. The reclaimed lagoon is intended to have various uses, including teaching canoe/kayak safety, environmental education, and passive recreation such as birding and exercise, and is a public facility, available to schools, other agencies, associations, and anyone who might want to use it as a classroom.

This diverse ecology is designed to encourage waterfowl, wading birds as well as all types of water loving animal habitats.

Upon researching the permitting for such a project, the Landscape Architect and their wetland consultants consulted the US Army Corps of Engineers as well as the state permitting agency, SC DHEC. After numerous discussions it was determined that if no exterior waters entered the pond and no normal waters left the pond there would be no permitting from any agency. This was determined to be very desirable as this new wetland habitat matures because the designers and the city wanted to retain the ability to manage and/or modify the habitat if ever needed. One of the important design features of this project is the ability to monitor and document the maturation of this conversion of an upland pond into natural wetland.

River access was a major requirement for this project as the EMS did not have a safe secure point for rescues from this river. Likewise, the public did not have a safe point to enter and exit this river which at one time was the major transportation method to this township.

The entire site was sculptured using only existing soils. The cut and fill balanced thus reducing the construction price greatly. Upon completion, the entire project was vegetated with a wetland wildlife habitat seed mix and the higher areas were seeded with a meadow wildlife mix. These mixes will allow and encourage the natural vegetation to establish and determine the mature ecosystem.

Surrounding the pond and along the interior dikes there is approximately one mile of gravel walking trails. Due to the virus, the visitation has not reached its potential. However, the entire park has become a regular for the anticipate outdoor/water orientate enthusiast as well as the local high school cross-country team.

The Landscape Architect was the prime design firm which provided all project management, design, grading, vegetation specifications, and boat ramp design.

Louis Jackson of Greenepond environmental provided the environmental/permitting. Joe Smith, PE of Geo-systems provided the geo-technical and structural engineering.

As seen in LASN magazine, January 2021.

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