Stanislaus Hydropower Tunnel Fish Screen Project

Stanislaus Hydropower Tunnel Fish Screen Project


This 550 cfs (355.5 MGD, 56,067 m3/h) hydropower facility diverts was from the Stanislaus River to generate electricity. As a part of FERC relicensing, the facility was required to install 1.75-mm slot size wedge wire screens with an approach velocity of 0.4 fps (12.2 cm/s) to minimize potential entrainment of resident trout (Rainbow Trout and Brown Trout). The screens are contained in a gradually narrowing concrete channel to maintain sweeping velocities as water is diverted into the screens and then onto the hydropower turbines. A fish bypass is located at the downstream end of the concrete channel to provide for safe downstream passage.

Benefit of ISI System

ISI's retrievable brush-cleaned cylindrical screen system was selected as the project's preferred alternative as the cylindrical screen design provided the necessary screen surface area with a reduced facility footprint compared to other concepts and the retrievable screen design allows inspection and maintenance of individual screen units without shutting down hydropower operations.


Pacific Gas & Electric Company (PG&E)


Black & Veatch

General Contractor:

Syblon Reid


Stanislaus River, Sand Bar Dam, CA

Year Installed:


Slot Size:

1.75 mm

Screen Model:


Drive System:



Electrical Generation

Water Body:


Flow Rate:

550 cfs (355.5 MGD, 56,067 m3/h)

Screen Type:

T Screens (dual cylinders)

Retrieval Systems:

Retrievable Vertical Track

Number of Screens:


©1996-2021 Intake Screens, Inc. All Rights Reserved.