Marchonahally Dam, (Markonahalli Reservoir) has been the life-saving water source for irrigating over 6,000 hectares of land spread over villages around Kunigal. It is located around 50 km from Tumkur town. This reservoir was built in 1930 during the reign of Mysore Maharaja Sri Krishnaraja Wadiyar IV. The automatic siphon system dam designed by Sir M Vishveshwaraiah was built across Shimsha, one of the tributaries of River Cauvery. Markonahalli dam is said to be a unique water resource management project as the reservoir has automatic siphon spillways, considered to be an efficient flood control system requiring no manual operations. Close to Marconahalli is the Mangala dam and a small hillock crowned by a Venkataramanaswamy temple.