The Khulna Water Supply Project in Bangladesh has connected 90 per cent of the city’s residents – up from 23 per cent – to safe drinking water.
Before the completion of the Khulna Water Supply Project, residents had to share public taps or build their own wells to access drinking water. Only 23 per cent of the Bangladeshi city’s population could turn on a tap and enjoy a safe water supply. That number now stands at 90 per cent, with 900,000 more Khulna residents having clean water to drink.
For the past seven years, SMEC has played a pivotal role in the US$259 million Khulna Water Supply Project, not only providing engineering expertise but also establishing governance at a local level.
Mr Liaquat Al Faruque, SMEC General Manager, Water & Environment in Bangladesh, remarked that the health and community benefits of the project could not be underestimated.
“Although this project was challenging on several fronts, our teams on the ground implemented innovative strategies to solve these problems, so that most residents in the city now enjoy access to pipe-supplied drinking water.
“These outcomes assist the Bangladesh government in achieving its Poverty Reduction Strategy target, in particular where water is concerned,” he said.
In association with ACE Consultants and partners, SMEC provided a full range of consultancy services for the project, including architectural, mechanical, electrical, civil and structural engineering, resiliency solutions and construction supervision.
“By using only raw water from the river and avoiding the common practice of extracting unsustainable ground water, we have made a substantial difference to not only Khulna’s people but also its environment”
Mr Liaquat Al Faruque, SMEC General Manager, Water & Environment, Bangladesh
SMEC also supported the Khulna Water Supply and Sewerage Authority (KWASA) – a relatively new water entity – with institutional reform, financial management and accounting, public utility management and community development, as well as monitoring and evaluation of the project.
Launched in 2012, the sheer scale of the project coupled with the unique environment meant overcoming several significant hurdles in the design and construction phases.
Due to land acquisition issues, the site layout plan was changed three times within the Surface Water Treatment Plant (SWTP) and intake areas.
“The design team had to revise the foundation design, pile dimensions and footings several times to meet the challenges of variation orders,” Mr Faruque said.
There were also dewatering issues during the concreting of the canal bottom slab and vertical wall. The dewatering process, which involved extracting and removing water from the intake area, had to be completed before constructing the bottom slab and vertical wall of the intake canal.
“We recommended that the contractor install 24 deep tube wells around the intake canal. These wells were operated continuously by motor for a period of three months, “explained Mr Faruque.
“Also due to the site conditions, we used reinstated ductile iron (DI) pipes so that the dewatering system could be operated without any hindrances.
“It was important for us to think outside of the box and challenge our theories so that we could bring this project to life, and I’m really proud of what we have achieved,” he added.
The water supply facilities of the project are significant and include one water intake with a capacity of 110,000m3 per day, a 33-kilometre raw water transmission pipeline, an impounding reservoir of 775,000 m3 and a water treatment plant.
As part of the project, a 706-metre-long steel pipeline with a one metre diameter was installed under the Rupsha River. This was completed using the horizontal directional drilling technique, making it the largest water supply pipeline to be constructed under a river in Bangladesh using this method.
In response to high flood levels during 2017, SMEC’s teams revised the design using numerical models to better protect against future river activity and potential climate change. A key element of the project was to ensure the facilities were constructed to be climate proof and produce an environmentally sustainable water supply.
“Bangladesh has increasing salinity intrusion along its rivers due to sea levels rising,” explained Mr. Faruque.
“By using only raw water from the river and avoiding the common practice of extracting unsustainable ground water, we have made a substantial difference to not only Khulna’s people but also its environment,” he said.