Pulhal aeri, or Pulhal lake, sometimes spelled Puzhal lake, also known as the Red Hills Lake, is located in Red Hills, Chennai, India. It lies in Thiruvallur district of Tamil Nadu state. It is one of the two rain-fed reservoirs from where water is drawn for supply to Chennai City, the other one being the Chembarambakkam Lake and Porur Lake. The full capacity of the lake is 3,300 million ft³ (93 million m³). History The Pulhal reservoir was built in 1876 during the British rule in Pulhal, Chennai, The reservoir was originally a small tank with a capacity of 500 million cubic feet (mcft) and two masonry weirs, built using locally available laterite stones, then functioned as surplus weirs to release excess water from the water body. Today, these masonry weirs are water-retaining structures as they have been replaced by two shutters. In 1997, the storage capacity of the water reservoir was increased to 3,300 mcft and the depth to 21.20 ft to cater to the drinking water needs of Chennai and also to store Krishna river water received from Andhra Pradesh through Poondi Reservoir and the Sholavaram Tank. Until 2012, the Water Resources Department (WRD) has only taken up maintenance work worth of 500,000 every year. Geography There are two masonry weirs in the reservoir. One weir is 178 m long and the other is 220 m long and 15 ft deep. The bund measures 5 m and runs to a distance of 7 km. The weirs have turned porous over the years. The south west part of the reservoir has Ambattur residential locality and has the main road to reach Avadi junction. Water treatment plant and Pulhal Central prison is located in the east part of the reservoir and has the highway road to reach CMBT and North Chennai. The North part has Padiyanallur village Thiruvallur koot road en route to reach Thiruvallur. There are two ways reservoir's bund road routes are located north east part of the reservoir, one bund route is from Alamaram junction to Redhills market junction and the other one bund road is from Redhills bypass road junction to Surapet junction. The North west part has Pammathukulam, Pothur, Attanthangal and Naravarikuppam villages. Jones Tower Jones Tower was built in 1881 in Pulhal lake. It is used to measure the depth of the lake water level. The surrounding bund roads are used by many for