The Mahaweli Water Security Investment Program (MWSIP) is a development program implemented by the Ministry of Mahaweli Development and Environment (MMDE) under the Government of Sri Lanka (GOSL). The Ministry has established a Program Management Unit (PMU) with support from the Mahaweli Authority of Sri Lanka (MASL) and the Department of Irrigation (DOI) to execute the Program. The MWSIP is funded by the Asian Development Bank (ADB) under a multi-tranche financing facility. The cost of MWSIP is estimated at US$ 675 million. Finance assistance from the ADB and co-financiers is US$ 567 million and Government of Sri Lanka provides USD 108 million. The investment program is being implemented from 2015 to 2024.