Structure-Free Zone - SFZ

These plans provide the necessary details and definitions for design and construction of the structure-free zone for a fish passable structure.

The Structure-Free Zone (SFZ) plans may be used when designing a fish passable structure to convey stream flows underneath a roadway. The SFZ is an imaginary, rectangular prism of infinite length both upstream and downstream that is horizontally centered on the stream and which represents the minimum boundary within which no part of the fish passage structure, including footings, shall be allowed.

SFZ incorporates additional width and height beyond the minimum hydraulic opening, not hydraulic related, such as constructability, maintenance access, wildlife connectivity, or other project specific needs. The plans are to be used in conjunction with Section 2.30B of the Request for Proposal (RFP).

The photo shows the application of the SFZ on Little Minter Creek, SR 302 MP 11.44.

The photo shows the application of the SFZ on Little Minter Creek, SR 302 MP 11.44.


View Structure Free Zone plan sheet (PDF 495KB)
Download the Structure Free Zone WinZip file (ZIP 195KB)
(WinZip file contains the following file formats: .dgn, .dwg files)

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