Between the Trees Blog

River Restoration: Small Dredges Prove Useful in Waterways

Written by Paul Olander, Senior Project Manager | March 25, 2020

As the sun on the dredging season in the Midwest inland areas began to set, operations were starting to heat up on the east coast for Nelosca Technologies (Nelosca). For a third straight year, Nelosca has had the opportunity to procure work in the milder maritime climate throughout New England during the winter months. These months are key for in-water work on the east coast as they provide opportunities to revitalize salt marshes, re-nourish beaches and restore navigation outside of the fish migration and spawning windows. Generally, this work has been undertaken in and near the coastal salt marshes adjacent to the smaller resort communities.

City Dredging in Downtown Waterways

This season, good fortune shone on Nelosca's Environmental group as we procured a winter river restoration project in Rhode Island. The general scope for this project remained along the lines of past work, where we restore river depths to facilitate and improve water quality, fish migration, but this one came with a twist; its footprint was tightly nestled within the low bridges and bustling infrastructure of Waterplace Park in downtown Providence, RI.

Waterplace Park is well known on the eastern seaboard for hosting its sensational nighttime WaterFire events, which attract 1 million visitors annually to WaterFire Circle in downtown Providence. This portion of the Providence and Woonasquatucket Rivers is crucial to the seasonal migration of anadromous fish species.

Over approximately 4 decades of urban influence which includes run-off of road sand during winter weather, the river had sedimented to the point where the aesthetics at low tide were beginning to lack, and the fish migration route became nearly impossible (photo below).

Providence and Woonasquatucket River Dredging Begins

Our Nelosca crew began mobilizing personnel and equipment to the project site during early November. By Thanksgiving, our crew had assembled a high-speed dewatering system some two miles away, moved the dredge Grand Calumet through and under a ridiculous amount of low-clearance bridge spans. A dedicated 12-member team worked diligently 24/7 from this point forward, focused on removing sand and debris from Waterplace Park beginning in the upstream extents progressing down.

Plastic Waste Slowed River Restoration Operations

Debris, mostly in the form of single-use plastic products, were commingled with the target material at staggering proportions. This debris significantly hindered the effective operating time of the dredge and transport system and in many cases accounted for up to 40% of the day lost due to pump and cutterhead cleanings. 

Beyond plastic, our team encounter and removed 16 electric scooters and 17 bikes from the Providence and Woonasquatucket River. The patience and professionalism of the team ultimately persevered in the end, completing the goals of the project within the required time window and without any injuries.

Small Dredge Makes Important Impact in Downtown Waterway

When it was all said and done, the dredge Grand Calumet removed 12,385 cubic yards of sediment material, most of which was sand, and dewatered it for potential beneficial reuse in East Providence. This project was a shining example of the importance of teamwork and communication both internally and externally to Nelosca.

The onsite crew provided innovative and effective solutions to the stakeholders for complex issues. In return, the team had full support from our client; The Nature Conservancy, along with the City of Providence, State of Rhode Island, Providence Foundation, Woonasquatucket River Watershed Council, WaterFire Providence and all the local residence of Providence, RI.

Waterplace Park Dredging: BEFORE AND AFTER

 

You might also be interested in the full 2-minute project overview video here!

Read more on Nelosca's environmental services and river restoration experience.