By Nusrat Yasmin, Roksana Hasib, and Saima Sultana Jaba, Dhaka Community Managers
পানির অপর নাম জীবন। কিন্তু ঘন জনবসতিপূর্ণ ঢাকার দেড় কোটি মানুষের ব্যবহারের জন্য পানির যোগান দেওয়া দিন দিন কঠিন হয়ে পড়ছে। জনসংখ্যা বৃদ্ধি পাওয়ায় নদি-খাল-বিলের পানি ব্যবহারের অযোগ্য হয়ে পড়েছে । উপরন্তু বেআইনি জনবসতি এবং বস্তিতে পানি সরবরাহ করার প্রক্রিয়া আরও জটিল। ঢাকা শহরে দূষণ মুক্ত পানি সরবরাহ করার দায়িত্ব ডিওয়াসার। পানি সমস্যা সমাধানে বুয়েটের তিনজন শিক্ষক “ইন্টিগ্রেটেড ওয়াটার রিসোর্স ম্যানেজমেন্ট” পরিকল্পনা তৈরি করে । তাদের পদ্ধতিতে চারটি বিষয় প্রাধান্য পেয়েছেঃ আর্থসামাজিক সমস্যা, বায়োফিজিকাল সমস্যা, প্রাতিষ্ঠানিক সমস্যা এবং পানির মান বিষয়ক সমস্যা। বৃষ্টির পানি সংগ্রহ করে এবং পুনর্ব্যাবহারের মাধ্যমে পানির সরবরাহ বৃদ্ধি করা সম্ভব। একটি পরীক্ষামূলক গবেষণায় দেখা গিয়েছে যে বাংলাদেশে শতকরা ৬০ ভাগ বার্ষিক বৃষ্টিপাতের পানি পদ্ধতিকরনের মাধ্যমে পুনরায় ব্যবহার করলে ঢাকা শহরের বার্ষিক পানি চাহিদার ১৫% পূর্ণ করা সম্ভব। এই পরিকল্পনা বাস্তবায়নের প্রচেষ্টা চালাচ্ছে ডিওওাসা। সকল সরকারীভবনগুলোতে এখন বৃষ্টির পানি সংগ্রহ করা বাধ্যতামূলক করেছে রাজধানী উন্নয়ন কর্তৃপক্ষ (রাজউক)।
In the popular saying Panir opor nam jibon, water is referred to as the “second life.” Water has always been a source of great challenge as well as distress for the resident of Dhaka, a city of 15 million people. Growing populations result in ground water depletion and increasing pollution, which leads to a lack of surface water usability. These factors make water issues acute for the DWASA, the main government water supplier. The intensity of the problem deepens when it comes to the slum and squatter residents, who have little or no DWASA water supply because they live in unstable and illegal settlements. In addition to a crisis of access, the quality of DWASA water (bad smell, microorganisms, presence of ammonia and arsenic, excessive chlorination) poses a great threat to people’s health.
Abdul Zobbar, a day laborer in urban Dhaka with a family of seven people, helps to visualize the slum residents’ water issues. He earns 4500 taka per month, out of which 1200 taka has to be used for rent. His family has to spend five taka each day for 10 liters of drinking water, which they have to collect after a tiresome wait of one to one-and-a-half hours in a long queue. Even after this, due to the poor quality of water, his family members suffer from different waterborne diseases.
As a solution to DWASA’s water management problems, S. K. Biswas, S. B. Mahtab, and M. M. Rahman from the Department of Water Resources Engineering at the Bangladesh University of Engineering and Technology have come up with a plan with the name Integrated Water Resource Management (IWRM). Their approach integrates four major components: socio-economic issues, biophysical issues, institutional issues, and water quality issues. In order to balance between supply and demand for water, the group recommended several possibilities, such as rainwater harvesting and reclaiming, and recycling and reusing water. Among these strategies, rainwater harvesting has already proved to be a great success upon implementation by DWASA and the Institute of Water Modeling (IWM) on their own office rooftops. The pilot research showed that in a monsoon country like Bangladesh, if 60 percent of annual rainfall can be harvested, it can fulfill 15 percent of Dhaka’s annual water demand.
In addition to rainwater harvesting, recycling and reusing of water has been implemented by DWASA and the IWM in order to save potable water for drinking and reducing water demand. In the recycling process, the soiled water is first filtered and then pumped into a ground reservoir, where it is mixed and diluted with storm water and then treated again. Recycled water from industrial entities can be reusable for non-potable purposes like dust control, soil compaction, and cooling water, whereas home recycled water can be reused for shower, sinks, washing, gardens, and so on. The successful implementation of rainwater harvesting and water recycling in pilot programs has motivated the Dhaka City Development Authority to make it mandatory for every city building with a roof more than 200 square meters in size to partake in rain water harvesting and recycling.
Although they’re being applied by very few, these different water management options open up great possibilities for solving Dhaka’s water needs. However, in order for them to be implemented, effort is required on the part of the government and private water management institutions in order to make people aware of the existing solutions. Additionally, for Dhaka’s water supply and management, a very donor-driven sector, continuity of technical assistance and grants from various bilateral and multilateral institutions is needed to make sure the projects are implemented.