HYDERABAD, Nov 19: Heavy pressure of water is chipping away at the flood-ravaged, old and worn out structure of Hamal lake regulator at RD-346 of the flood protective embankment and it may collapse at any moment, fears Haleem Adil Sheikh, adviser to Sindh chief minister on relief.
The adviser visited the site on Monday after getting a letter from the project director of the Right Bank Outfall Drain (RBOD-I) on Nov 14 in which the official expressed fear the regulator would collapse at any moment because of increasing pressure of water. The letter was also sent to the Wapda.
“After getting the letter, I submitted a note to the chief minister in which I expressed fear the regulator may collapse and suggested long-term measures by the federal government to save it,” said the adviser.
Sindh chief minister has sought a detailed report from irrigation authorities on the state of regulator.
The project director accuses irrigation authorities of opening the regulator’s gates ‘abnormally’ and jeopardising the entire structure. The irrigation staff opened all five gates up to 5.5 feet. As a result, the regulator’s pavement and its right wing wall were damaged and left wing developed cracks on Nov 12, said the letter.
The right wing wall had already washed away and its pavement damaged. The regulator regulates flow of water from Hamal lake into the Main Nara Valley (MNV) drain that ultimately takes it to Manchhar lake. The irrigation department was asked verbally to operate gates at 2 to 3ft but they opened it up to 5.5ft, posing serious threat to the structure, said the official.
Mr Sheikh asked Wapda authorities to open an alternate escape route along flood protective bund. “The weakened regulator poses a constant threat to the areas of Qambar-Shahdadkot, Khairpur Nathan Shah and Johi,” he said, adding machinery had been sent to the site to open a gate.
Built in 1932, the regulator has been rendered weak by successive heavy rains since 2007 and then exceptionally heavy rains and floods in 2010.
Provincial secretary of irrigation Babar Effendi disagreed with the project director and said if the irrigation staff had lowered the gates further the pressure of water would have washed away the whole structure.
“In fact, the regulator had not been properly maintained after 2007 rains and super flood of 2010 which had rendered it weak,” he said.
He said the gates were operated according to engineering methodology. “We try to keep cut-off level within safe limits,” he said.
Cut-off level is difference between upstream and downstream flows which is to be kept within safe limits. That was why, he said, Hamal lake’s gauge level had dropped to 9.5ft but now it had again risen to 10.1ft gradually.
“After damage to the right wing wall and cracks in the left wing wall, one gates on the right and left side have been closed and we are operating only three gates now,” he said.
He said that he had asked Wapda to open an alternate escape channel at RD-412 upstream FP bund at Miro Khan zero point. It gets water from Hamal lake and disposes it of into a drain that runs parallel to the bund for some distance before entering MNV Drain.
“But unfortunately, the escape channel’s gate is not being opened by Wapda officials…,” he said.
He said the escape route if used would also allow water travelling along FP bund to enter MNV drain. A new regulator of Hamal lake had been built and its gates are to be installed.
“In the next monsoon season, there will be no threat to the area as the new regulator built by Wapda will start working by then,” he said. In the absence of an escape route, water from FP bund was entering Hamal lake and increasing the lake’s level.
The adviser said the new regulator should be opened as soon as possible. “If we had not pressed the irrigation authorities to close the gates of the regulator it would have spelt disaster given shabby condition of the regulator’s structure,” he said. Many areas in upper Sindh are still under water. These include parts of union councils Faridabad, Sanwaro Pat Ghulam Mohammad, Qambar, Chinni and Drig Bala.
Effendi said the old regulator should have been maintained properly because it helped keep Hamal lake at safe level by releasing water into MNV.
Maximum gate level of the lake was recorded at 14ft last year. Since all connecting drains carry water to the lake it has to be emptied gradually and kept within safe limits.