The second phase of Detroit's Milliken State Park includes a wetlands demonstration area that showcases nature's water filtration. Collected stormwater passes through a swirl separator to remove suspended solids, oil and grease. The stormwater is then pumped into a four-foot deep sediment forebay, which allows additional sediment to drop out before entering three-foot deep pools with emergent plants. Finally, the water passes through 18-inch deep braided wetland streams to increase vegetation and stormwater interaction for maximum filtering, before passing over a weir and entering the river. This view is looking west toward the Renaissance Center. Purple pickerelweed and hardstem bulrushes are in the center, with "Blue Flag' iris and water plantain in the foreground. The open water is about 4' deep.

Detroit's Milliken G. State Park and Harbor was previously an industrial waterfront brownfield site underlain with contaminated soil and abandoned infrastructure, which included concrete shipping docks, railroad turntables and underground utilities. According to the Michigan Department of Natural Resources, this is Michigan's first state park in an urban setting.

Nested within a larger riverfront network of pedestrian access and event venues, lowland park's 6.1 acres, the second phase of the 31-acre park, is part of a long-term economic strategy to catalyze capital investment in mixed-use redevelopment on the surrounding properties and is another piece of the puzzle that is helping to define the dramatic transformation of Detroit's riverfront. Currently, the park helps generate a projected $5.82 million annually in economic activity from visitor spending and is expected to generate $152.3 million in multi-family residential development within the site's watershed.

Seems hard to believe, but according to the Michigan Department of Natural Resources, this is Michigan's first state park in an urban setting. The landscape creates native habitat for 62 confirmed species of migratory and resident birds, which were not present on the previous brownfield, including Virginia rails, red-winged blackbirds, swamp sparrows and marsh wrens, as well as bullfrogs, green frogs and painted turtles.

Connecting the Park to the East RiverWalk
The lowland park connects 3.5 miles of the Detroit East RiverWalk to the southern trailhead of the 1.4 mile-long Dequindre Cut trail. The trail extends from the river north to the popular Eastern Market and Midtown residential districts. This connection plays a key role in enhancing nonmotorized circulation and providing linkages to existing and proposed trail networks in the city. The park also provides recreational access along the urban riverfront for residents and 39,000 downtown employees. Concrete hardscapes and stainless steel cable railing provide over 500 feet of riverfront fishing accessibility, as well as biking, wildlife viewing and observing the frequent ocean-going vessels on the international river. The park's 450 trees and shrubs on the once largely unvegetated site also helps sequester three tons of carbon annually.

The park honors Peter Stroh, former chairman of the Stroh Brewing Co. (founded in Detroit in 1850), an advocate for the restoration and improvement of the Detroit River, with a bronze bust, plaque, water feature, courtyard sculpture (by Mino Kramer) and seating area. This is one of the park's lushest areas, boasting "Green Mountain' sugar maples, American sycamores, ironwoods, "Shadblow' serviceberry, "Jim Dandy' winterberry male pollinators, "Shaver' winterberry, "Nick's' compact juniper, "Summerwine' ninebark, Canadian wild rye, Black-eyed Susans, woody thyme, "Waterperry' blue speedwell and "Blue Flag' iris.

The park provides a space for outdoor recreation and relaxation for a projected one million visitors per year; offers lunch time and after work hours educational and recreational activities to the nearly 11,000 people working in the nearby General Motors Renaissance Center complex; and affords educational opportunities for more than 1,641 visitors through the Department of Natural Resources (DNR) Explorer programs to share information, conduct tours and answer questions about the park and the riverwalk. Programs and topics addressed include Fishing 101; What Kind of Fish is This?; Detroit Riverfront Birding; Bird Conservation through Citizen Science; Michigan State Parks: Connecting Michiganders to Nature and History; and What is the Michigan DNR? Growth in attendance has increased over 300 percent since the program began in 2010.

Interpretive Shelters
Additional education is offered through five ADA accessible interpretive shelters with signage illustrating the native, industrial and social history of the riverfront. A memorial to Peter Stroh, former chairman of the Stroh Brewing Company (founded in Detroit in 1850), features a bronze bust, plaque, water feature and an 800-square foot concrete courtyard with seating centrally located in the park. The memorial commemorates this noted conservationist who advocated for public access to the riverfront.

 

The pedestrian and nonmotorized trail is designed to encourage a range of users. The color concrete is by Scofield. In contrast to other open spaces on the waterfront, the park was designed with limited manicured landscape areas, relying instead on a palette of native materials. "Green Mountain' sugar maples and red oak canopy trees are in this view looking east.

The site of Detroit's Milliken G. State Park was previously an industrial waterfront brownfield site underlain with contaminated soil and abandoned infrastructure, which included concrete shipping docks, railroad turntables and underground utilities. Formerly home to parking lots, shipping yards and cement silos, the "lowland park" phase two development was a great opportunity to continue the transformation along the river. Contaminated soils were capped in-place, and a wetland placed atop the brownfield, separated by a clay layer to minimize infiltration and exfiltration. Capping the contaminated soils, versus complete soil removal and remediation, resulted in over $250,000 in savings, or almost 18 percent of the project cost.

SmithGroupJJR worked closely with Michigan Department of Natural Resources staff to develop interpretative signage that explains how the wetlands naturally remove pollutants from the water and return it to the Detroit River as clean water, all without routing it to a wastewater treatment plant. This view looks east to the interpretive area. "Knockout' roses, a nonnative cultivar, and "Shadblow' serviceberry and Redbud understory trees are in the foreground. The slopes have a native upland seed mix and the islands a wet meadow-type seed mix. The railings and signage were custom manufactured by Future Fabricating of Warren Michigan. The cantilevered roofs have inset panels and punched roof panels.

Wetlands and Stormwater Management
A key design component of the second phase of the park development was developing a park/stormwater management demonstration area to manage the runoff from adjacent properties, one strategy to make those properties more attractive for redevelopment. Current municipal regulations require the construction of costly stormwater detention systems as part of any intensive development. Creating a park to manage stormwater from the surrounding land would eliminate the need for this infrastructure on the adjacent parcels. The design challenge was two-fold: The designers needed to create a wetland large enough to filter runoff during storm events, while still receiving enough water to keep the wetland charged during dry periods; and second, the site contained contaminated soil left over from the previous industrial facility. Based on calculations of maximum and minimum surface flows from adjacent properties, the designers built the largest wetland the site can reasonably accommodate to treat runoff from the largest surrounding area possible. The resulting wetlands capture stormwater from 12.5 adjacent acres of developable land. Collected stormwater passes through a swirl separator to remove suspended solids, oil and grease. The stormwater is then pumped into a four-foot deep sediment forebay, which allows additional sediment to drop out before entering three-foot deep pools with emergent plants. Finally, it passes through 18-inch deep, braided wetland streams to increase vegetation and stormwater interaction for maximum filtering before passing over a weir and entering the Detroit River.

SmithGroupJJR worked closely with Michigan Department of Natural Resources staff to develop interpretative signage that explains how the wetlands naturally remove pollutants from the water and return it to the Detroit River as clean water, all without routing it to a wastewater treatment plant. This view looks east to the interpretive area. "Knockout' roses, a nonnative cultivar, and "Shadblow' serviceberry and Redbud understory trees are in the foreground. The slopes have a native upland seed mix and the islands a wet meadow-type seed mix. The railings and signage were custom manufactured by Future Fabricating of Warren Michigan. The cantilevered roofs have inset panels and punched roof panels.

Water plants include "Blue Flag' iris, American lotus, yellow and white waterlily, Sago pondweed, Arrowhead, Hardstem bulrush, pickerelweed, woolgrass and wild celery. During periods of minimal inflow, supplementary river water can be pumped into the wetland to keep inflow and outflow in equilibrium. The contaminated soils were capped in-place, as the wetland was perched on top of the brownfield, separated by a clay layer to minimize infiltration and exfiltration.

When the adjacent property is developed, the wetlands will filter 4.5 million gallons of runoff annually and remove from it an anticipated 99 percent of sediment, 91 percent of phosphorus, 74 percent of nitrogen, 97 percent of lead, 91 percent copper and 87 percent of zinc. In addition, the capping of the contaminated soils, versus complete soil removal and remediation, resulted in over $250,000 in savings, or almost 18 percent of the project cost.

New Bird Habitat
The wetland is home to 10 aquatic plant species, 32 native forb and grass species, 20 native tree and shrub species. The landscape creates native habitat for 62 confirmed species of migratory and resident birds, which were not present on the previous brownfield. Species onsite include birds sensitive to loss of wetlands, such as Virginia rails, red-winged blackbirds, swamp sparrows and marsh wrens, as well as species of reptiles and amphibians such as bullfrogs, green frogs and painted turtles.

Project Team
Client: Michigan Department of Natural Resources
Landscape Architect: SmithGroupJJR
Cultural Resources Investigations: Commonwealth Cultural Resources Group, Inc.
Geotechnical Investigation and Construction Testing: NTH Consultants, Ltd.
Brownfield Environmental Consultin: MACTEC Engineering and Consulting
Electrical Engineering: Applied Power and Controls
General Contractor: Anglin Civil Constructors
Irrigation Contractor: Weatherain


Subcontractors
Bridges: Asphalt Paving: T & M Asphalt Paving
Concrete: Barthel Contracting
Electrical: Rauhorn Electrical
Landscaping: W. H. Canon


Manufacturers
Lighting: Beta Lighting
Pond Liner: CETCO Lining Technologies
Rails and Interpretive Structures: Future Fabricating