By late January, I’m in spring fantasy mode, training my gaze past the chilled air and ice-ruts toward the widening afternoon light and the steadfast songs of birds who, like me, do not migrate. In this spirit, I look forward to the emergence from the snow of a graceful new parking lot at the south end of Lake Calhoun.
Construction of the new lot and most of the landscaping was completed in late fall by the Minneapolis Park & Recreation Board (MPRB). This maintenance project replaces the former parking lot which was a piece of the old parkway. Constructed in the 1970s, the pavement had decayed and the drive lane was too narrow to meet current code. Furthermore, the lot posed safety risks to pedestrians due to its open proximity to the bike path.
A primary objective of the MPRB was storm water management. Runoff from city streets and parking lots into local waterways seriously compromises aquatic life and water quality. Water that flows from parking lots typically carries automobile toxins such as gasoline, engine oil, residue from tires and trace metals. Sand and salt from winter ice treatment and litter also wash from the pavement.
Project manager Andrea Weber refers to a “redundancy for capturing water” in the design. Three rain garden chambers have been constructed at intervals along the edge of the elongated lot. Each rain garden is a depression planted with native species whose deep roots will wick rainwater and snow melt into the ground. A second feature is the use of permeable pavers – paving stones with interstices – in the parking bays on the north side of the lot and a grass paving system for overflow parking on the south side. This latter system comprises a plastic reinforcement grid sunk into the topsoil, which will be over-seeded with grass in the spring. The only impervious surface is the bituminous central drive lane and turnaround. According to Andrea Weber, “the total impervious area has been reduced by 42%, though the overall parking lot is only 7% smaller than the old one.”
An underground drain tile will collect water after it has been filtered through the naturally sandy substrate and then channel it through storm sewer pipes. When it enters the lake, the water will be clean. A third feature for handling storm water is a “beehive dome.” This structure protrudes above ground at the east end of the lot and will accommodate overflow from the rain gardens and permeable pavement in the rare event of excessive rainfall.
To address safety concerns, the landscape architect (Amy Bower of Hoisington Koegler Group, Inc.) added a low hedge between the parking bays and the bike path. Crossings of the bike path are flagged by neon yellow signs and pavement markings.
In addition to being greener and safer than the old lot, the new one will be far comelier. The topography undulates gently, and native perennials, grasses and swamp white oaks (to be planted this spring) will attract birds and butterflies. The streetlight standards are reproductions of elegant historic fixtures. Educational signage illustrating and explaining the system for filtering storm water will be installed this spring. Due to its location along the Park system’s popular Grand Rounds, the parking lot will demonstrate good environmental stewardship to numerous annual visitors and local residents.
The cost of constructing the parking lot stayed within the original budget of $350,000. According to an MPRB press release, funding for the maintenance project came from Minnesota State Lottery proceeds.
There is little to see now except the streetlight standards poised like herons above the snow. But come spring, we can welcome a new green space to the shores of Lake Calhoun, a parking lot that is as much park as pavement.