The scarcity of water and insufficient fresh water resources to meet human and environmental requirements is one of the problems that the world suffers from at the present time (Hameed & Al Thamiry, 2022). Therefore, water distribution systems require effective management and accurate measurement of water. Water management and measurement are necessary, especially in irrigation projects to maintain water delivery to all and know the amount of water applied inside the farms (Raza et al., 2007). Flow measurement in open canals and irrigation networks is one of the essential elements of water management (Vatankhah & Mohammadi, 2020). Among the hydraulic structures used to measure flow in open channels is the venturi flume, which is the most common in irrigation networks due to its simple geometry and ease of manufacture. Reducing the cross-section of the venturi flume is one of the simplest and least expensive ways to measure flow discharge in open channels (Samani & Magallanez, 2002). The Venturi flume consists of three sections, the upstream, the throat, and the downstream. To measure the discharge in a Venturi flume, two head measurements are made, one in the upstream area and the other at the throat, and it is calculated using the discharge formula.

Toney L. Wahl (2002) evaluated the operational limitations of shrink-width ducts using a series of culverts with comparable geometry but different throat length-to-width ratios. The broadest flumes' modular limits were discovered to be less than the values that the theory had projected. Guidelines for the design of flumes with contracted widths are also given in this work.

Mustafa Gogusa et al., (2012) investigated the impact of the downstream transition region, various models are investigated. Studying the discharge coefficient, approach velocity, and modular limit values is done for this. To determine which kind of downstream transition area would result in the largest modular limit, these quantities are then connected to form a set of curves.

In this study, Sathe et al., (2016) proposed a new, narrower design for a small Venturi flume. The project's width reduction ratios for the small flume to channel width (b/B) are 0.33, 0.50, and 0.66. Investigating the potential for building cost savings is the goal of such a reduction. Calibrate the little venturi flume concurrently so that it can continue to be used as a flow meter in open channels. The experimentation with one of the tiny venturi flumes (b/B = 0.50) is currently complete, and the other two tests are being conducted.

Willi H. Hager (1989) investigated at the Venturi flume's flow characteristics if it was limited by objects with rough edges and thin covers. These parts are mounted directly on the floor and ceiling and are frequently seen in the side walls of rectangular canals used in large municipal sewers. The head discharge equation for various contraction rates, specific immersion, and a description of the internal flow mechanism are all given particular attention. A brand-new discharge measurement tool that features a sharp channel width decrease is demonstrated. This works well for mobile use in sewage system's as big rectangular canals.

Samad Emamgholizadeh and Kazem Assare (2008) conducted a series of experiments in the flow measurement flume of rectangular cross section. The coefficient of long throat discharge depends on various parameters such as upstream and downstream slope, step height and throat length. The study showed that the decrease in the upstream slope leads to an increase in the discharge coefficient and when the downstream slope increases, the discharge coefficient of the flume increases.

This study aims to propose a new design for a miniature venturi flume that is used to calculate the inflow of fields and farms in irrigation projects for the purpose of reducing water losses resulting from adding quantities exceeding the actual need.