Prime Minister Imran Khan has formally approved a barrage on Indus River upstream of Sindh’s delta. The project is aimed at addressing the long-standing water-related issues in Sindh’s areas downstream Kotri Barrage. Also, it is meant to supplement drinking water to the cosmopolitan city of Karachi.
The project which is located about 45km upstream of River’s outfall into the sea, 65km south of Thatta and 130km east of Karachi city, has been named `Sindh Barrage.
The project is being floated as a mega scheme to address water issues in downstream of Kotri Barrage. The issues include sea intrusion in the delta, the adverse impact of climate change, loss of wetland habitats, mangroves and marine life, non-availability of fresh water for irrigation and domestic use and resultant mass migration.
WAPDA Chairman Lt Gen (R) Muzammil claims it’s a unique project that will not only help the government finally end the water-related issues but also bring back life in the area.
The barrage will store 2 to 3 MAF and utilize 4.1 MAF of valuable resources. The objectives include reduction in seawater intrusion and improvement in mangrove growth and marine life, irrigation water supply (5000 cusecs) to surrounding areas, improvement of the ecology of Indus river downstream of Kotri, flood mitigation for surrounding 75,000 acres land and supply of 1000 MGD to Karachi and other towns.
PC-II for the feasibility study of the project would cost Rs350 million approximately.
The proposed project is scheduled to be completed in December 2024 by adopting a fast-track strategy. Wapda plans to commence the feasibility study next month followed by its vetting by international consultants by December 2020 and completion of detailed engineering design by December 2021, says authority’s papers.
The construction of the project will start in January 2022 and be complete in December 2024.
Devastation in delta
The Indus Delta—the 5th largest in the world—has shrunk from 12,900 square kilometers to just 1,000 square kilometers raising a serious alarm in the 200-year period.
The contraction of the delta has reached 92 percent, shows a study conducted by a team of five academics of the US Aid-supported Centre for Advanced Studies in Water (USPCASW) at Mehran University of Engineering and Technology (MUET), Jamshoro.
The study led by a researcher Prof Dr Altaf Ali Siyal took 15 months to establish the facts.
The researchers looked into changes taking place since 1833 when this great delta was stretched over 12,900 sq km. It began shrinking for two reasons. One, the human factor and the other, continuous reduction in the flow of river water into the sea. It can be judged by a revelation that the delta had as many as 17 active creeks which have reduced to just two only. They include Khobar and Khar creeks.
Not only the delta but also threatened is the mangroves forest—the 7th biggest in the world and fed by this delta. Now, it is confronted with sea intrusion and salinity due to declining river flows. Climate change has added more threats to the milieu.
The researchers studied satellite images of the Indus delta’s creeks of the last 45 years starting from 1972. The creeks were divided into four zones, with two each on the right and left banks of the river. On the left side, the area from Sir Creek to Wari Creek was designated as zone I while the area between Wari and Khobar creeks was termed zone II. On the right side, the area between Khobar and Daboo creeks was designated as zone III while the area between Daboo and Phitti creeks was termed zone IV.
The study measured the shoreline erosion rate to be 45.69 meters per year in the zone I and 52.1m per year in zone II. In zone III and zone IV, 27.21m per year and 31.43m per year erosion were calculated respectively.
The highest intrusion was observed in zone II where the sea has encroached upon 1.24km, followed by zone I where 1.1km was conquered by the sea.
The Indus delta lies in Thatta and Sujawal districts. According to the study, the latter district, which is located on the left bank, has suffered more from the erosion.
During the last four-and-a-half decades, the sea also added 42,609 hectares of delta in its tidal flood plain (TFP), which is submerged during high tide. In 1972, the pace of TFP was measured at 7.1%, whereas by 2017, it almost tripled to over 18%.
Some 81,324 hectares of the TFP is covered by mangroves, including thick mangroves, which occupy 36,245 hectares and thin mangroves, which occupy 45,079 hectares. However, the total percentage of the TFP covered by mangroves is just 12%.
Water bodies containing seawater in the delta have doubled from 1,600 sq km to 3,000 sq km, Prof Siyal said. “We find a lake after every two to three kilometers in the delta,” he added.
The research also studied the effects of sea intrusion on the local population. According to it, 76% of locals use underground water to drink, which has become brackish and saline in over 88% area of the delta.
Turbidity, electrical conductivity, acidity level and percentages of chloride and arsenic in the underground water have been found far beyond the World Health Organisation’s permissible limits.
Besides the sea intrusion, the study also researched changes in temperature and perspiration. It found that from 1960 to 1990, an average of 100 millimeters of rain was recorded during the monsoon in July. However, during the period from 1990 to 2015, a drop of 40% in rainfall was recorded. Similarly, the average temperature from March to July also showed an increase in the period from 1990 to 2015.
According to the study, the delta produced 5,000 tons of fish in 1951. But the catch has now drastically slumped to only 295 tons.
The researchers have proposed the construction of a sea levee covering at least 200km of the coastline. Also, they call for increasing the flow of water in the Pinyari and KB Feeder canals, restoring 15 defunct creeks, plantation of mangroves, cultivation of halophytes, increasing farming of shrimps and crabs, releasing 10 million acre-feet of water downstream Kotri barrage and promoting tourism.
What Sindh government thinks about Sindh Barrage
Advisor to the Chief Minister Sindh for irrigation Ashfaq Memon says Sindh government had already included the feasibility study of Delta Barrage in the current Annual Development Program of the Sindh government.
The objectives of the authority for constructing a dam downstream of Kotri and the aims of the Sindh government do not clash and they instead converge at the same point.
Some people in Sindh government say WAPDA has emulated Sindh’s project as they had already made it a part of their ADP 2019-20. Sindh government has earmarked an amount for the feasibility study for the barrage.
Some 3 to 4 years back, the Senate Committee on water led by then Senator Dr. Karim Khuwaja had extensively deliberated upon the devastation in deltaic areas of Sindh. After a series of meetings, the committee compiled a comprehensive report which also had the construction of a barrage in its recommendations.
Ashfaq Memon who had also attended few such meetings said the report was shared with the federal as well the Sindh government. Thus, the suggested remedies were available at Islamabad as well as Karachi.
He told Engineering Review that the barrage was important for stopping devastation downstream Kotri and also for providing drinking water to Karachi which is Sindh’s capital. The provincial government has been asking the center for allocating 1200 cusecs of water to Karachi from the federal pool as Karachi houses the population from across the country. This barrage may be the point where Karachi would be given water be it from Sindh’s share or from the joint share.
A surprise project
No one in Sindh or a scant number of people in Sindh province knew that WAPDA was to move the Sindh Barrage project. A number of informed irrigation experts were blank when Engineering Review talked to them about the project. ‘There was no consultation with Sindh and thus they were totally blank’, said one of them.
The element of surprise has created doubts in the province and many smell a move which some people say maybe against the interests of the province. A Sindh government officer suspects the project may be aimed at creating a justification for constructing Kala Bagh Dam on the Indus River.n
