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Mohawk River Ice Jam Monitoring

The Mohawk River between New York State Barge Canal Locks 7 and 8 near Schenectady, NY is susceptible to ice jams during periods of river-ice break-up. Ice jams in this reach typically form at channel constrictions, bridge piers, lock and dam structures, and sections with a reduced floodplain (Foster and others, 2011). Ice jam related flooding can result from backwater associated with the jam or from water released downstream when a jam fails. Schenectady is particularly vulnerable to ice jam related flooding; Lederer and Garver (2001) estimated that 80% of historic Mohawk River floods in Schenectady have been associated with winter snowmelt and associated ice floes.

In cooperation with the New York State Department of Environmental Conservation's Mohawk River Basin Program, the New York State Power Authority, Brookfield Renewable Power, and Union College, USGS is monitoring river elevation at two streamgages between Locks 7 and 8. A web camera installed at a third location, between the gages, in the Stockade District of Schenectady, provides real-time images of the river during winter months.

A clickable map with the monitoring locations identified (as dots) is displayed at right. USGS streamgages (orange dots) with links to station information are listed below:

01354330 - Mohawk River at Lock 8 near Schenectady

01354500 - Mohawk River at Freeman's Bridge at Schenectady

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  • Dec 1, 2014 - Web camera is back online for the season.
  • Dec 12 - Some moisture from this past week's storm is partially obscuring the web cam view. The view will be corrected no later than the 17th.

River Ice Conditions - Model Residual

USGS Water-data graph for site 01354330

Subscribe here for WaterAlert updates for the model residual.

Model Residual - Explained

The model residual shown above is the difference in water elevation between what we observe and what we predict at Lock 8. Lock 8 predictions are based on ice-free conditions, so when there is no ice in the river to restrict flow, the model residuals are about zero. When the residual rises during winter months, this usually indicates that ice in the river between the gages is restricting streamflow and causing water to backup at Lock 8. A positive residual value can be thought of as extra water stored in the river at Lock 8 due to ice.

It is important to keep in mind that the residual is generally reflective of conditions between the gages. Ice jams occuring upstream of Lock 8 or downstream of Freeman's Bridge may not be reflected in the model residual.

River Ice Conditions - Stockade Web Cam

Camera Instructions - You can take temporary control of the camera by clicking "Control Now" in the bottom right corner, then selecting one of the preset views. There may be a delay of a few seconds between selecting the view and the camera moving. You can use the buttons at the bottom right to take a snapshot or view the image in fullscreen.

Image Archive - Time-lapse images from the camera are available.

Emergency and Flood Information

River Elevation

Add 200 feet to the gage heights shown below to convert to feet above the National Geodetic Vertical Datum of 1929 (NGVD29). Data shown are PROVISIONAL and subject to revision.

PLEASE NOTE - NGVD29 is NOT the same as the New York State Barge Canal Datum. To approximate the NYS Barge Canal elevation add 201 feet to the values shown

Mohawk River at Lock 8 near Schenectady

USGS Water-data graph for site 01354330

Mohawk River at Freeman's Bridge at Schenectady

USGS Water-data graph for site 01354500

For More Information

Gary Wall
USGS New York Water Science Center
425 Jordan Rd.
Troy, NY 12180

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Page Last Modified: Friday, 12-Dec-2014 12:30:48 EST