All the excess soil, used as the compression layer or “surcharge,” has been removed from Isles’ west bay area and transferred to the west side of the north arm. Needed additional fill was hauled in from remote locations to the east side of the north arm.

The west bay forms the northwest section of the lake, and the north arm is the long thin “arm” that extends north to Franklin Avenue. The parkland around these two areas has the highest concentrations of peat soils around Isles and are, therefore, the most subject to settling. Bringing all the fill and compression material into the area was part of an innovative and fairly complex engineering strategy, called “surcharging,” to forestall the inevitable settling: first the parkland is filled in above the 100-year flood level; additional soil is then laid atop the fill soil; the weight of the compression layer compresses the next fifty years of settling into a few months. With the west bay compression complete, the excess soil has now been removed, and the process is being repeated around the north arm.

The fill material, which has all come from local construction projects, most notably the excavation for the Guthrie Theater complex, is full of rocks. This is very common in the glacial soils found in Minnesota. When the west bay compression layer was removed, many rocks were exposed. The area was plowed to expose even more rocks, and all were removed. The parkland around the west bay was regraded and then seeded to keep dust and mud under control until next spring when work on the final west bay improvements will begin.

To prevent erosion of the compression layer’s extra three feet surrounding the north arm, silt fences were installed—one near the shore, the other at the top of the incline—and the area between the fences immediately seeded.

A woodchip walking path has been laid around the newly filled in north arm area. Around the west bay, the existing bike path will be shared with walkers until the new walking path is constructed next year.

Project Manager Tim Brown expects to have the west bay improvements, which include shoreline naturalization, landscaping, and new bike and pedestrian pathways, out for bid next January so work can begin as soon as weather permits in the spring. He anticipates that the surcharge will be removed from the north arm next summer and that north arm shoreline, landscaping and pathways improvements will be completed sometime next fall.

Steady progress is being achieved on the overall Isles renovation. The shorelines on the both sides of Kenilworth Lagoon have been stabilized, and a new wetland / flood storage area created east of the Off-Leash Recreation Area on the south side of the lake. The WPA-era retaining wall at Evergreen Point has been replaced, complete with new railing. On the lake’s south east side, the shoreline has been stabilized, new pedestrian and bike paths constructed, and trees planted. Work to create a wetland and improve the open play field at the southwest end of the park has also been completed.

The Lake of the Isles Renovation to date has been funded through the Minnesota Environment and Natural Resource Trust Fund: Legislative Commission on Minnesota Resources, the Minnesota DNR Flood Mitigation Program, the Metropolitan Parks and Open Space Commission, East Isles Residents Association, Kenwood Isles Area Association, Lowry Hill East Neighborhood Association, Cedar Isles Dean Neighborhood Association, and private donations.

The Lake of the Isles Renovation is a Minneapolis Park and Recreation Board project that lies in the 4th Park District, represented by Commissioner Vivian Mason. Please contact project manager Tim Brown at 612-230-6400 for further information.