Due to irregularities in irrigation, maximum water of irrigation is going waste and on the other hand because of excessive use of water during irrigation, groundwater level is reducing at an alarming rate.
According to the Agriculture Ministry’s monitoring report, where efficient use of water in the irrigation system in the whole world is more than 50 percent, Bangladesh can use 38 percent only resulting in 62 percent water going waste. Different organizations and research institutes say that 79 percent of the country’s total water demand is being met from underground water. While only 21 percent demand is fulfilling from surface water. Which indicates the country totally depends on groundwater.
According to the International Water Management Institute (IWMI), Bangladesh is in the worst case of irrigation water among the rice production countries. Countries like Nepal, Australia, Switzerland, Sweden, Denmark, Yemen, Iran and Peru are using highest 70 percent of irrigation water. While many countries are rapidly improving their water use in irrigation, Bangladesh is progressing slowly.
According to agriculture ministry, the country approximately cultivates rice on around one crore hectares of land annually. Of this only Boro is cultivated on 47-48 lakh hectares which requires maximum water. In addition, water is also needed for cultivation of wheat and maize.
These seals are used in some 37, 175 deep tube wells, 1388960 shallow tube wells and 176478 low lift pumps. Of these tube-wells, 3,33,664 are run by electricity and 12,78,959 run by diesel.
For irrigation, demand for daily electricity stands between 1,500 to 1,700 megawatt.
Due to inefficient use of irrigation water, water level has dropped considerably in the last few decades. According to the Bangladesh Water Development Corporation (BADC), underground water level due to irrigation water level in the Ganges, Meghna and Brahmaputra basins adjacent to west, northwestern and northeast of the country falls from four inches to one and half feet per year.
The government has taken steps for expansion of various projects and technologies to reduce the pressure on groundwater, but implementation rate is slow. On the other hand, rampant use of deep tube is wells also increasing all over the country.
Over the decade, the number of deep tube wells has doubled. Due to weakness of the policy, the use of deep tube wells is increasing uncontrollably.
BADC has developed a system known as BAIRD pipe which works to tunnel water from deep tube well to field. But this is not expanding to a satisfactory level. Development-related organizations kept the process of experimental testing in different areas of the country for last three years.
Last year BADC established 561 kilometers BAIRD pipe in the country. BADC wants to implement more such projects across the country.
If irrigation can be made efficient, cost of production will go down. Agriculture ministry information showed, of the total per hector Boro production, irrigation cost was 16.3 percent in 2007-08. But during 2016-17, the irrigation cost was 12.54 percent. It is possible to reduce the irrigation cost by minimizing inefficiency of irrigation system.
Basically use of irrigation water is inefficient due to the weakness of distribution and application methods. To prevent this, the use of technology that is effective must be increased. In addition to popularizing these technologies, farmers should be given incentives and training and at the same time unregistered deep and shallow tube wells installation should be stopped.
As a model of alternative irrigation, BADC created ‘Pattukua’ model, which can reduce the pressure of underground water. Steps should be taken to make the model popular among the farmers.
According to the government office sources, the government is trying to expand the technology to reduce the cost of farmers and to prevent waste of land through the best use of irrigation water. Instead of conventional treatment and technology, there are many latest techniques for water efficient irrigation systems being taken to the field.
On the other hand, BADC has plans to increase the amount of irrigated land to 60 lakh hectares using only surface water.
Construction of Surface and Sub surface pipeline (underground pipeline) for the reduction of water wastage, rehabilitation of old deep tube wells, repair and maintenance are also continuing. It is also working to improve the irrigation efficiency to 48 percent and constructing various types of hydraulic structures to increase the water conservation of rain water and surface water.
In addition to tackling the risks of climate change, prevention of pollution of the environment, and also to create alternative sources of income for farmers, agricultural irrigation projects have been taken up by solar-powered pumps at a cost of Tk 407 crore. It will reduce the cost of irrigation to almost half of the present cost.