BGM layers to help stop leakage from Mutha right bank canal
PUNE The Khadakwasla Irrigation division has decided to use the bituminous geomembrane (BGM) technique to stop leakage from the Mutha right bank canal of the Khadakwasla dam, and to avoid the canal breaching at passes through the Pune Municipal Corporation (PMC) areas.
Last week, the state water resource department gave instructions to use the BGM waterproofing techniques to stop leakages and animals from burrowing, which can lead to the waters breaching the canal banks.
Normally, animals burrow from either the water-side or the banks, extending laterally into the canal embankment or foundation.
Due to these phenomena, the Mutha right canal breached in September 2018, and inundated nearby areas, affecting 200 families living in the slums at Dandekar bridge near Parvati.
After the incident, Maharashtra water resource minister Girish Mahajan had claimed that irrigation officials informed him that it was suspected that rats and other rodents might have weakened the foundation of the wall by burrowing, which led to the incident.
The state government also formed a committee headed by TN Munde, then chief engineer, Pune irrigation division, to find reasons behind the breach in the wall. The committee had mentioned a lack of maintenance and burrowing animals as the cause of the incident.
According to the Khadakwasla irrigation division, it had found 14 dangerous spots over 28km on the Khadakwasla dam to Hadapsar stretch, in the PMC limits.
The total length of the canal is 202km, from Khadakwasla dam to Indapur taluka.
H V Gunale, chief engineer of the water resource department, Pune division, said, “BGM technique was used in the Pench water project in Vidarbha region and has given good results. So, water resources ministry has instructed us to incorporate techniques in canal and dam construction. We have also decided to use BGM to stop leakage of the Mutha right canal and strengthen it.”
“As per our report, water leakage from the canal is 2.25 thousand million cubic feet (TMC) per year. We have started a survey of the canal and identified a vulnerable stretch for water leakages. After the report, we will use BMG techniques to stop leakages,” he added.
TN Munde, director of Maharashtra Krishna Valley development corporation (MKVDC), said, “As mentioned in committee report, due to water leakages and earthen embankment of canal, burrowing animals creates holes in the embankment and the piping action busted the canal.”
“We recommended lining the canal to stop leakages. Mutha right bank canal wwhich was constructed in 1960 and it is a mono-zone type manually constructed canal. BGM is an easy, time-saving technique. It is ready-made sheets of BGM. We have to just lay the BGM layer. Traditional concrete laying takes time,” he added.
Benefits of BGM
-BGM, or the bituminous geomembrane, is a specialty geomembrane with composite layers that make it stronger, more watertight and more durable than resin- based geomembranes.
-It prevents burrowing animals from making holes in the embankment of the canal.
-It also stops erosion of soil and weeds.
-It is durable and enhances water carrying capacity.
-It is cheaper than traditional cement concretisation layers.