Drone study highlights brook obstructions, recommends ways to improve flow, stem flooding

An eroded stream bank in the Township of Washington exposes a manhole cover that was identified as a critical sanitary issue in Boswell Engineering's "Musquapsink Condition Assessment Report." Michael Olohan photo

TOWNSHIP OF WASHINGTON—A report that lists nearly 100 obstructions along the Musquapsink Brook — a Category One protected waterway that leads to Oradell Reservoir — lists two unnamed tributaries as “C1” waterways but not the unnamed tributary that runs behind the site of a proposed 17,100-square-foot retail plaza at Pascack Road and Washington Avenue.

(And recently, a Boswell Engineering official, Kevin Boswell, said the unnamed tributary was not a “regulated waterway” nor a “C1” waterway because it drained only 48.832 acres and not the 50 acres required under NJDEP Flood Hazard Area Act rules. 

(See “So close! Drainage basin nears proposed mall shy of 50-acre threshold,” Michael Olohan, April 24, 2022, Pascack Press.)

An engineering study based on a drone flyover of the 3.6-mile-long Musquapsink Brook that flows through the township revealed nearly 100 concerns impairing stream flow, likely increasing flooding and threatening water quality. It offers recommendations to address them.

The drone study of the brook is the first completed study of a Pascack Valley waterway to help alleviate increasing flooding concerns plaguing the area’s towns. Recently Pascack Press reported that Westwood was considering a drone study.  (See “Council floats on drone study of brook, Michael Olohan, March 27, 2023, Pascack Press.)

The Boswell Engineering study of the Musquapsink Brook lists 45 downed trees and 33 sediment shoals as obstructions, 14 areas where stream banks require stabilizing and five potential “critical sanitary issues” where the stream runs near a sanitary sewer line, and offers recommendations to help improve stream flow and minimize local flooding.

Moreover, the report cited one issue that requires the “utmost priority.”

It also lists other “critical sanitary issues” where the brook either runs near or around a sanitary sewer structure or sewer line that could potentially expose human and household wastes to the stream flow or allow stream flow to enter a sanitary sewer line.

“The current condition of the bank near critical sanitary issue (7-1) should be reconstructed with the utmost priority. A flooding event could result in a failure of the sanitary system causing approximately 25% of the town’s untreated sanitary flow to discharge directly into the Brook,” states the report. 

The exposed sanitary manhole — exposed to brook flows on three sides — appears south of Washington Avenue and west of Pascack Road, but the report only provides “northing” and “easting” coordinates. One report photo of the site shows a newer-looking residential complex in the background that appears elevated behind a white composite fence.

No costs were provided for the needed upgrades in the report, although the report details what state Department of Environmental Protection permits are needed for all the recommended work, including tree removals, shoal remediation, and fixing the streambank and sanitary sewer issues.

The cost for the Musquapsink Brook drone study also could not be immediately determined. Requests for the report’s cost were not returned by press time.

Pascack Press asked the mayor and council president to comment on the report. Mayor Peter Calamari did not respond.

We asked Council President Desserie Morgan if the council planned to discuss the report. “No plans have been discussed,” she told us.

The report, titled “Musquapsink Brook Condition Assessment” concludes, “The Township may want to explore obtaining grant monies from the (Natural Resources Conservation Service) for the stream stabilization in the area of the sanitary sewer line bank erosion. By removing the obstruction within the watercourse this will help to alleviate nuisance flooding caused by the obstructions by reducing the displacement of floodwaters and increase the available capacity of the waterway.” 

It continues, “Additionally, it would be in the best interest of the Township to apply for and receive an Individual Permit to stabilize the eroded banks of the Musquapsink Brook to reduce the amount of sediment being displaced and deposited within the channel.”

The 70-page report by Boswell Engineering, dated February 2023, obtained by Pascack Press via a public records request, breaks the brook’s 3.6-mile path through the township into eight sections. It does not provide a prioritized list for repairs of the obstructions identified, not cost estimates for the possible work needed.

However, the report provides recommendations to remove obstructions and improve stream flow in each of eight sections surveyed by the drone, which also were walked and physically inspected by Boswell engineers.

“With the intent to alleviate nuisance flooding within the floodplain, various obstructions were identified and categorized within a Photograph Summary (Attachment A) containing a photograph ID and a picture of the existing condition. Each photograph sheet was broken down and organized to correspond with the original eight sections in which the watercourse was surveyed with the drone,” states the Boswell report.

Another Pascack Valley town, Westwood, plans to conduct a drone study of Musquapsink Brook soon, according to Mayor Raymond Arroyo in a recent letter to Pascack Press. (See “Background on towns’ brook study,” April 3, 2023, Pascack Press.) 

Moreover, the Pascack Valley Mayors Association is also hoping to work with Veolia North America, owner of Woodcliff Lake and Oradell reservoirs, on possibly subsidizing additional drone studies of the Musquapsink and Pascack brooks, he said. 

Unnamed tribs cited as “C1” waters

On a related matter, the report identifies two “UNTs” or unnamed tributaries to the Musquapsink Brook. The report lists these unnamed tributaries — one above Schlegel Lake and one below — as “FW2-NTC1” waterways, which stands for freshwater, non-trout, Category One.  It lists obstructions on one unnamed tributary including a sediment shoal and three fallen trees.

However, the drone study does not list an unnamed tributary that runs behind the proposed Four Seasons Marketplace retail plaza and a half-dozen Meisten Street homes. That tributary, also labeled a man-made ditch on some maps and a stream on others, joins with the Musquapsink Brook before it heads to Schlegel Lake.

We reached out to Boswell on April 10 for an explanation on why the unnamed tributary that runs behind Meisten Street homes — which runs 24/7 — was not listed in the Boswell report. We did not receive a reply by press time.

The report notes, “The surface water classification for the Musquapsink Brook is FW2-NTC1. This categorization is defined as a watercourse that is not suitable as a fishery resource while remaining a Category 1 stream. Category 1 waters, as defined by the New Jersey Department of Environmental Protection (NJDEP), are protected from any measurable changes in water quality because of their exceptional ecological significance, exceptional recreational significance, exceptional water supply significance, or exceptional fishery resources.” 

Nearby Meisten Street, Burke Street and Northgate Condominium residents — especially Meisten Street resident Michael Agnello of 667 Meisten Street — have pressed the Township Council to help determine whether the waterway behind his home is a Category One (or C1) waterway due to its significance as a water-supply source since it eventually leads to Pascack Brook that flows to the Oradell Reservoir.

In a listing of Category One waterways and tributaries found online under the state’s Administrative Code, it states, “ORADELL RESERVOIR (Oradell) FW2-NT(C1)TRIBUTARIES (Oradell) — All named and unnamed tributaries that FW2-NT(C1) are not listed separately, that drain into Oradell Reservoir above the Oradell Dam” N.J. Admin. Code § 7:9B-1.15. That statement appears to indicate all tributaries to the Oradell Reservoir are protected (C1) waterways.

The report’s introduction notes, “The Musquapsink Brook spans 8.5 miles taking water from the Borough of Woodcliff Lake through four (4) municipalities before flowing into the Pascack Brook in the Borough of Westwood. The surface water classification for the Musquapsink Brook is FW2-NTC1. This categorization is defined as a watercourse that is not suitable as a fishery resource while remaining a Category 1 stream.”

“Category 1 waters, as defined by the New Jersey Department of Environmental Protection (NJDEP), are protected from any measurable changes in water quality because of their exceptional ecological significance, exceptional recreational significance, exceptional water supply significance, or exceptional fishery resources,” states Boswell’s report.

45 downed trees

The report also provides photos of 45 downed trees obstructing brook flow, plus 33 sediment shoals, or islands of sediment that have built up in areas where eroded soil from stream banks have accumulated and caused obstructions and reduced stream capacity. 

Multiple photos included in the report show downed trees and debris blocking the brook’s flow, heavily eroded stream banks due to intense storm flows, and large shoals which water flow around during non-storm periods and also reduce stream capacity during heavy runoff events.

Moreover, the “critical sanitary” issues identified included erosion near a sanitary sewer line, an open sanitary sewer manhole cover, stream bank erosion exposing a concrete sanitary manhole on three sides which was cited as an “utmost priority,” and one exposing a manhole cover on one side, and an eroding stream bank near another sanitary manhole. 

The report urges attention to each of the possible “critical” sanitary issues that could cause impaired water quality due to possible exposure to wastewater from homes and businesses.