BS ISO 26906-2015 PDF

Full title and description

STB BS ISO 26906-2015 — Hydrometry — Fishpasses at flow measurement structures. This international standard (ISO 26906:2015) gives requirements and guidance for integrating fishpasses with flow‑measurement/gauging structures so that fish migration is supported without unduly compromising hydrometric performance. It identifies fishpass types with acceptable hydrometric calibration data and describes methods to determine combined discharge and to estimate measurement uncertainty for installations where a fishpass and a flow‑measurement structure operate together.

Abstract

ISO 26906:2015 (second edition) specifies design, installation, calibration and operational requirements for fishpasses located at or adjacent to flow measurement structures. The standard covers site selection, instrumentation (head/level measurement), permissible fishpass types with established discharge relationships (for which calibration data exist), methods to compute flows in the gauging structure and the fishpass separately or combined, and procedures to quantify and report uncertainty. The document aims to balance ecological objectives (fish passage) and hydrometric accuracy.

General information

• Status: Published (ISO: confirmed at 5‑year review; BS adoption published/confirmed).
• Publication date: ISO second edition published October 2015 (2015‑10); British adoption published 30 November 2015 (BS ISO 26906:2015).
• Publisher: International Organization for Standardization (ISO); British Standards Institution (BSI) for the BS adoption (BS ISO 26906:2015). The prefix "STB" in your title suggests a national adoption label — check the relevant national standards body for confirmation of an STB designation.
• ICS / categories: 17.120.20 (Flow in open channels / Hydrometry).
• Edition / version: ISO — 2nd edition (2015). Adopted as BS ISO 26906:2015.
• Number of pages: ISO edition: approximately 48 pages; BS published edition typically issued with additional BSI front matter (commonly listed as ~60 pages).

Scope

The standard applies to combined installations where a fishpass is provided at, or adjacent to, a structure that is used to measure open‑channel flow (weirs, flumes and similar gauging structures). It covers: selection and siting of the fishpass and gauging structure; hydraulic and geometric requirements for fishpasses that have acceptable hydrometric behaviour; instrumentation and measurement arrangements needed to determine flow through each path; calibration, monitoring and maintenance; and methods for combining measured or inferred flows and for assessing the uncertainty of the total discharge.

Key topics and requirements

• Design principles for integrating fishpasses with gauging/weir/flume structures while minimising adverse effects on hydrometric performance.
• Identification of fishpass types with satisfactory hydrometric calibration (examples include Larinier super‑active baffle passes, Dutch pool & orifice designs and some pool‑type passes with V‑shaped overfalls).
• Site investigation and selection criteria (approach/channel geometry, availability of a bypass channel, downstream conditions, scouring risks).
• Instrumentation requirements — head/level sensing positions, zeroing, and, where necessary, dual head measurements to detect submerged (drowned) conditions.
• Methods to determine fishpass discharge: separate measurement (head gauges on each path) or inference/transference methods when only a single head is measured.
• Calibration and discharge coefficient determination for fishpass types and guidance for applying calibrated relationships.
• Procedures to compute combined flows and to estimate and report measurement uncertainty for the total discharge.
• Operational guidance: maintenance, debris control, monitoring (including remote surveillance where appropriate) and documentation of changes affecting hydrometry or passage performance.

Typical use and users

Used by hydrometric and civil engineers, water resources and river managers, environmental and fisheries engineers, dam and weir designers, regulatory authorities and consultants. Typical applications include new or upgraded gauging stations at weirs and flumes where fish migration must be provided for, retrofits to existing gauging structures to add fishpasses, and routine operation/maintenance and uncertainty assessment of combined flow and fishpass installations.

Related standards

ISO 26906 sits within the hydrometry suite of standards and is typically used alongside other standards covering gauging structures, vocabulary and uncertainty. Relevant related documents include: ISO 14139 (flow measurements in open channels using compound gauging structures), ISO 772 (hydrometry — vocabulary and symbols), ISO 1100 series (measurement of liquid flow in open channels / gauging station guidance), and guidance on measurement uncertainty (e.g., ISO/IEC Guide 98‑3 / GUM and hydrometric uncertainty guidance documents).

Keywords

hydrometry; fishpass; fish passage; flow measurement; gauging structure; weir; flume; discharge calibration; measurement uncertainty; Larinier; pool & orifice; compound gauging; site selection; instrumentation; maintenance.

FAQ

Q: What is this standard?

A: ISO 26906:2015 (adopted as BS ISO 26906:2015) is an international standard providing requirements and guidance for integrating fishpasses with flow measurement (gauging) structures so both ecological passage and reliable flow measurement can be achieved.

Q: What does it cover?

A: It covers design and siting of fishpasses at gauging structures, fishpass types with acceptable hydrometric calibration data, installation and instrumentation for flow measurement, calibration methods, procedures to combine separate flows, and guidance for estimating and reporting uncertainty of total discharge.

Q: Who typically uses it?

A: Hydrometric and civil engineers, fisheries and environmental engineers, water and river managers, regulatory bodies, dam/weir designers and consultants involved in gauging station design, operation and environmental mitigation.

Q: Is it current or superseded?

A: ISO 26906 was reissued as the second edition in 2015, replacing the 2009 edition. The ISO edition was subject to periodic review and has been maintained as the current edition (confirmed at its review). For national adoptions (BS ISO 26906:2015 and other local designations) check the issuing national standards body for any subsequent confirmations or amendments.

Q: Is it part of a series?

A: It is part of the broader hydrometry standards family produced by ISO/TC 113 (Hydrometry): it is used together with other hydrometry standards (for example, ISO 14139 on compound gauging structures, the ISO 1100 series on open‑channel flow measurement, and vocabulary/terms in ISO 772).

Q: What are the key keywords?

A: Hydrometry, fishpass, flow measurement, gauging structure, discharge calibration, measurement uncertainty, Larinier, pool & orifice, compound gauging, instrumentation.