Hydrology

Opportunistic Point Velocity Measurements

2003

Velocity measurements were collected by NRG to assess the potential suitability of spawning and rearing habitat for anadromous fish and to identify potential passage obstacles with respect to stream velocities.

Opportunistic point velocity measurements were taken between Drew Gardens and River Park, and especially at points throughout Bronx River Park. Sites are in potential rearing and spawning reaches as well as places suspected to be possible velocity barriers to fish passage.

Methods

Velocity readings were taken with a Marsh-McBirney Flow meter using 10 second averages.

Floating object measurements were taken 40-50 ft. from the bank, usually on the slower-flowing sides of the channel.

Results

Point Velocity Measurements on the Bronx River

3/26/03

Location	Velocity (ft/s) at 60% depth
River Park (at xs 3)	1.69
DG to River Park (at xs 2)	1.96
Drew Gardens (at xs 1)	1.57

6/5/03

Location	Depth (cm)	Dist from bank (ft)	Velocity (ft/s)
Location	Depth (cm)	Dist from bank (ft)	20% depth	80% depth	Avg.
At Bend - Point Bar Culvert at LB, DS of Burke Ave Bridge	110	~10	1.15	0.9	1.03
	90.00	~10	1.20	1.00	1.10
	102.00	~15	1.90	1.30	1.60
			Total Avg:		1.35
US of Kazimiroff Bridge on Left Channel	81.00	~3	1.17	0.96	1.07
	76.00	~7	1.52	1.18	1.35
			Total Avg:		1.21
Shoelace Boulder Vane 211th Street	88.00	~4	1.09	1.06	1.08
	105.00	~18	2.20	1.60	1.90
	107.00	~22	2.00	1.50	1.75
			Total Avg:		1.58
DS of Muskrat Cove Btw Nereid Bridge and Muskrat Cove	100.00	~7	2.45	2.00	2.23
	74.00	~8	1.30	1.10	1.20
	76.00	~20	2.30	1.90	2.10
	74.00	~25	2.70	2.30	2.50
			Total Avg:		1.93

6/13/03

Location	Depth (cm)	Dist from bank (ft)	Velocity (ft/s)
Location	Depth (cm)	Dist from bank (ft)	20% depth	80% depth	Avg.
Wild Asia	62	~10	0.64	0	0.32
Wild Asia	90	~11	0.5		0.25
DS of Fordham Brdge	85.00	~10	0.35	0.05	0.20

Floating Object Velocities (ft/s)

Location	Object	Time (s)	Distance (ft)	Velocity (ft/s)
Wild Asia	twigs/leaves	9.63	20.67	2.15
	twigs/leaves	12.89	20.67	1.60
	twigs/leaves	11.47	20.67	1.80
	twigs/leaves	15.8	20.67	1.31
			Avg:	1.72
DS of Fordham Bridge	orange peels	16.72	26.5	1.58
	orange peels	19.86	26.5	1.33
	orange peels	19.67	26.5	1.35
	orange peels	15.84	26.5	1.67
	orange peels	21.67	26.5	1.22
			Avg:	1.43

Download Opportunistic Point Velocity Measurement data
(Excel, 25KB)

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