The final cost to construct a new walking path along the riverbank in Swan Pond Park in Riverside could be $125,000 more than anticipated as elected officials mulls options to stabilize the shoreline where erosion is common during floods.
If the village decides to pursue the more expensive of two shoreline stabilization solutions and must add the permeable pavers to the path, the final cost would increase to roughly $600,500, or by roughly 26 percent.
Trustees earmarked $475,500 for the path replacement in the village’s 2021 capital projects budget. Most of the funding would come courtesy of two grants, including $350,000 from the 2019 Illinois Capital Bill and $50,000 from a grant through Cook County Department of Transportation and Highways.
According to Village Manager Jessica Frances, the tentative plan is to begin construction in July with completion slated for September.
“Once we have bids on the projects, we will be able to provide a final schedule,” Frances said.
The plan is to remove the narrow 2,078-foot-long asphalt path, built as part of a U.S. Army Corps of Engineers dam removal and park regrading project in 2012, and replace it with a 10-foot-wide exposed aggregate concrete path which would also be ADA-compliant.
Public Works Director Dan Tabb told trustees at their meeting on Feb. 18 that the project has entered the final design stage. With construction planned for summer 2021, trustees need to settle on how much more they want to spend now that the village’s share of the cost may rise to a total of $200,500.
The village did receive some good news last week regarding another potential added expense, when state Rep. Michael Zalewski (D-Riverside) informed Village President Ben Sells that he and his staff believe the village still qualifies for the $350,000 capital grant even if the path no longer will be permeable.
Last June, village trustees decided they preferred an all-concrete path and Sells asked Zalewski whether the state would allow the change. Because the path is located in a floodplain and the permeable pavers would have no impact during flood events, local officials felt making the path permeable would have no practical effect while also being more expensive.
If required, the permeable pavers would have been installed as they are in the two “green” alleys connecting Kent and York roads – as a brick paver ribbon framed in concrete.
“There’s an aesthetic part of me that thinks a ribbon looks good, but from a practical standpoint it doesn’t make any sense,” Sells said.
The Illinois Department of Commerce and Economic Opportunity grant for Riverside in the state’s 2019 Capital Bill was awarded for a “new permeable walking path.”
However, after talking to Zalewski last week, Sells said the village will pursue the all-concrete design.
“We’re going to move forward with the assurances of Representative Zalewski,” Sells said.
But trustees favored using the more expensive shoreline stabilization option, because the path is in such a high-profile area along the river.
“It’s a generational project on our river that I think we have to get right,” said Trustee Doug Pollock. “I think we learned from the asphalt that trying to save money on a project like this is not a prudent way to approach it.”
Trustees agreed with Village Engineer Orion Galey’s recommendation to stabilize the shoreline in three areas at the north end of Swan Pond Park using large limestone ledges, measuring about 2.5 feet wide, 4 to 6 feet long and about 10 inches thick.
The ledge rock would be placed in a stair-step fashion from the top of the bank to the river in an area near the WPA walled plaza, near the culvert outlet and along the path near the hill where the river bends east.
In all, the ledge rock would stretch a total of about 150 feet divided between the three areas. In addition, the final design will include using thicker concrete edges on the upstream and downstream sides of the path where it erodes as flood waters recede.
Galey said that a much cheaper solution would be large boulders called “riprap” set into the bank to stabilize it. That solution would add about $40,000 to the project cost, but their use would make the river in those areas inaccessible and would also require some ongoing maintenance.
“The limestone ledge rock is also eight to 10 times heavier than the riprap would be, so it’s a much more long-term solution,” Galey told trustees last month. “If you are looking for stabilization of those banks, I would recommend the limestone.”
Pollock said the limestone ledges would also tie in aesthetically with the WPA-era stone improvements already present.
Trustee Edward Hannon called the planned improvements a “legacy project” that would provide a permanent solution.
“I think [it] ties into what the objective of the board was when pushing this project forward to begin with, which was to add to the beautification of that section of town which I think is unique given its position on the river,” Hannon said.
Sells agreed, saying that “there’s no point of putting the path in if you don’t stabilize the bank. And if you’re going to stabilize the bank … we need to maintain access to the river, and from the aesthetics standpoint it’s a no-brainer.”