It is proposed to permanently divert the Sheldrake River, in southeast New York, from upstream of the confluence with the Mamaroneck River through a concrete-lined tunnel into the West Basin of the Mamaroneck Harbor. Included in the proposed plan are improvement of the existing channel, construction of an uncontrolled ogee drop structure and converging approach to a tunnel inlet portal, construction of 3,550 ft of concrete-lined tunnel, including a 16.25-ft-square section and a 17.5-ft horseshoe section with an intermediate transition, and construction of a standard stilling basin energy dissipater at the juncture with the West Basin. A 1:25-scale model was used to determine the flow conditions in the proposed project for Manning's ? values of 0.013 and 0.010 up to the Standard Project Flood (SPF), which peaked at 4,039 cfs. Tide effects were investigated for tides of -2.7 ft, 6.7 ft, 10.0 ft, and 16.8 ft, National Geodetic Vertical Datum. Flow conditions were improved in the model by modifying the tunnel alignment, the shape of the tunnel, and transitions near the middle of the tunnel. The stilling basin was modified to improve flow conditions for the varying tide effects. Riprap protection downstream of the stilling basin was verified as being adequate for the SPF. Stage-discharge relations were determined as were flow velocities and water-surface profiles in the tunnel approach. Hydraulic grade lines were determined for the tunnel for several flows. Flow velocities at the stilling basin end sill are presented as are velocities in the West Basin of the Mamaroneck Harbor.


    Access

    Download


    Export, share and cite



    Title :

    Sheldrake River Tunnel, Mamaroneck, New York: Hydraulic Model Investigation



    Published in:

    Publication date :

    1986


    Size :

    7978880


    Type of media :

    Report


    Type of material :

    Electronic Resource


    Language :

    English



    Classification :


    Kinzua Dam, Allegheny River, Pennsylvania and New York: Hydraulic Model Investigation

    Fenwick, William B. | HENRY – Federal Waterways Engineering and Research Institute (BAW) | 1989

    Free access



    Comite River Diversion, Comite River, Louisiana: Hydraulic Model Investigation

    Hite, John E. Jr. | HENRY – Federal Waterways Engineering and Research Institute (BAW) | 1994

    Free access

    Lake Dardanelle, Arkansas River: Hydraulic Model Investigation

    Foster, James Edward / Franco, John J. | HENRY – Federal Waterways Engineering and Research Institute (BAW) | 1977

    Free access