$26 Million Drainage Project Underway to Ease ‘Pop-Up Ponds’ in Northern UWS Section of Riverside Park

By Tracy Zwick

Joggers, dog-walkers, students, and neighbors who frequent the northern reaches of Riverside Park are all too familiar with the mini-lakes that pop up after a significant rainfall. The park’s most vulnerable section runs from just north of the 105th Street dog run all the way up to around 116th Street. A combination of the park’s aging drainage system and the increased severity of rain events means there is simply nowhere for all that water to go.

Now, a $26 million project funded by the mayor’s office is set to address “drainage and ponding issues” in this part of the park, according to Merritt Birnbaum, president and CEO of the non-profit Riverside Park Conservancy. The project will modernize the existing systems that deal with rainwater, allowing the water to funnel into appropriate outlets instead of flooding park walkways and lawn areas. 

Park visitors are already seeing the first stages of work. “Right now what you’re seeing is the staging area for the project,” Birnbaum explained, “and they’re starting to do some pruning of trees in the area,” which will allow construction vehicles to pass without incident. After that, “work will begin on the upper path to install new drainage.” 

“We’re preparing to put up signage soon (just waiting for final approval),” Birnbaum added in an email message, “to help people understand and navigate the park while the Parks Department contractors undertake the upgrades.” 

The project calls for the city’s Parks Department to replace old drain lines; add or enlarge catch basins; install bioswales, which are shallow, landscaped depressions designed to absorb water; and “make adjustments at key entrances along Riverside Drive to improve the flow of water into the drainage infrastructure,” Manhattan Borough Commissioner for NYC’s Department of Parks & Recreation Tricia Shimamura explained by email. In some cases, pathways in the park will be reconstructed and raised. 

Originally designed by Frederick Law Olmsted and expanded under Robert Moses in the mid-1930s, the park’s river-facing slope and nearly 100-year-old infrastructure – plus a paved perimeter that channels street runoff – create a surfeit of surface water in the park. In addition, flooding has intensified in recent years as major storms have increased in frequency and severity. “The park’s aging drainage infrastructure was never designed to handle such large volumes of water,” said Shimamura. 

Following a lengthy study and design period, construction teams are now prepping to “clean and replace failing infrastructure while adding drainage swales and, new to the park, wet meadows,” according to the conservancy’s website. Wet meadows are areas of land that stay wet most of the time but don’t have enough standing water to become swampy.  They’re often filled with grasses and wildflowers that thrive in damp soil. 

According to the website, three wet meadows will be installed in low spots in the affected part of Riverside Park, “with permeable sub-drainage and plantings of native grasses and perennials that thrive in intermittent wet conditions.” Those areas will “shift from lawn to resilient habitat, supporting pollinators and other small wildlife.” 

Park visitors can already see construction fencing and materials that will be used in the project near 108th Street. Pruning work will take place between 96th and 116th streets along Riverside Drive, and within the park, to clear tree branches; temporary path closures may occur periodically during this process. 

No date is set for when the project’s next phase will start, but when it does, the upper path in Riverside Park in and around the work area will be closed for drainage repairs, re-grading, and paving. When that happens, the 116th Street entry ramp and 108th Street entry stairs will remain open, and the 115th Street stairway will be closed. There will be additional work done at two intersections along Riverside Park: at 115th Street, where a lot of street water enters the park, and 108th Street, where there are several persistent sinkholes. 

Once the upper path paving and Riverside Drive work is complete and open, the reconstruction of the lower park path will begin. Work is expected to run through April 2027, according to the conservancy. Residents and friends of the park can stay up to date via the NYC Parks Capital Project Tracker and the conservancy’s website. 

Subscribe to West Side Rag’s FREE email newsletter here. And you can Support the Rag here.