Changes in characteristics due to land use change and global warming in the Lower Bengawan Solo Sub-watershed have resulted in a decrease in the availability of water in the watershed. This significantly affected the availability of raw water for drink water for Gresik Regency, as the worst occurred in the extreme dry month of 2018 for four months (June – September). However, this raw water shortage will be fulfilled if the construction of the barrage Sembayat is completed. With the construction of this infrastructure facility, Gresik Regency is planned to get additional raw water services of up to 1,000 liters per second; so that the local PDAM can guarantee the fulfillment of 3K elements (quality, quantity and continuity) throughout the years of service. Currently the raw water shortage in October is proposed to get a water supply of 40% of the total intake for the 1st and 2nd daily tenths Period, while for the 3rd daily tenth period it is 20%. In order to anticipate the condition of decreasing water availability in the downstream Bengawan Solo Sub-watershed, an integrated watershedbased water resource management policy is needed, so that there is a suitability management of one river, one plan and one management from upstream to downstream. This is done in order to maintain the sustainable water supply for many aspects in sustainably.

Keywords : water resource management, raw water utilization, continuity.