**3.3 Irrigation using river water**

A floating pontoon with the necessary centrifugal pumps is placed on the river. Pumps are used to draw water from the river and discharge it to the re-excavated canal through an underground pipeline. Water is then withdrawn from the canal by LLP to irrigate the crop fields. As indicated in **Figure 5**, it is a double-lifting irrigation system.

This system of pontoons on the rivers Padma, Mohanonda, and Atrai lessens groundwater exploitation by 7.08% for the respected Upazilas' area [29].

### **Figure 3.**

*Surface water augmentation by (a) re-excavated canal, (b) cross dam (check dam) in the re-excavated canal, (c) re-excavated pond and (d) re-excavated natural beel utensils (source: [22]).*

## **Figure 4.** *(a) Irrigation by electricity-driven and (b) solar-powered LLP utensils (source: [22]).*

## **Figure 5.**

*Double lifting irrigation system: (a) Pontoon with centrifugal pumps floating on the river and (b) discharging river water to the canal (source: [29]).*

## **Figure 6***.*

*A rubber dam was constructed across the river (source: [12]).*

The irrigation with river water is also operated by constructing a rubber dam across the river to conserve water upstream (**Figure 6**). The LLPs are used to irrigate the crop fields. A rubber dam built across the river Barnai in Puthia Upazila reduces groundwater withdrawals by 10.11% [29].
