HMI Geoglyph

Geoglyph// A large form or motif created in or on the land by humans from sediment, stones, or other clastic detritus. Geoglyphs often have a dual purpose; they are a kind of land art in that they express or reflect the values, stories, and aesthetics of a culture that makes them, and they were often made for practical purposes such as drainage or flood control, defense, or to create environments such as aquaculture ponds.

The HMI Geogplyph after initial construction.

Hart-Miller Island is a large island outside of the Baltimore Harbor in the Chesapeake Bay. It was built as a dredge material containment facility for the Port of Baltimore on the eroded remnants of Hart and Miller Islands. The 1,100 acre facility operated from 1981 to 2009, at which point it was nominally converted to a state park and turned over to the Maryland Department of Natural Resources. While the South Cell and outer edge of HMI are restored and serve habitat and public use functions, the 740-acre North Cell has significant maintenance costs, is overrun with phragmites, and does not support public recreational uses.

In 2017-2019, Brian worked with Mahan Rykiel Associates and the Port of Baltimore to develop a landforming technique that could assist in the control of phragmites and help achieve the creation of higher value habitat over time in the North Cell. The study and prototype aimed to work with the ongoing ditching operations to manage water levels and locations to limit the spread of phragmites and produce richer ecological assemblages with minimal future maintenance costs.

We studied the existing plant ecologies and soil produced from the storage of aerated harbor sediment, as well as the dimensions and actions of the pontoon excavator and its team of operators responsible for the ditching and water management on the North Cell. In 2018 we constructed a prototype to demonstrate the efficiency of the form and its potential to limit phragmites growth and prioritize microhabitats for other plants.

The geoglyph during fall, winter, and spring months retains water at the perimeter and limits the opportunities for the spread of phragmites.