悪水[akusui] undrinkable water
井戸水[idomizu] well water
一衣帯水[ichiitaisui] (being separated only by a) narrow strip of water
一水[issui] current (of water)
溢水[issui] inundation

飲水量[insuiryou] amount of drinking
飲料水[inryousui] drinking water
烏の行水[karasunogyouzui] quick bath
雲水[unsui] itinerant priest
塩化水素[enkasuiso] hydrogen chloride

貯める[tameru] to save (i.e. in a bank)
貯金[chokin] (bank) savings
貯金通帳[chokintsuuchou] bank book
貯金箱[chokinbako] savings box
貯水[chosui] storage of water

貯水池[chosuichi] reservoir
貯蔵[chozou] storage
貯蔵タンク[chozoutanku] storage tank
定額貯金[teigakuchokin] fixed amount (postal) savings
備荒貯蓄[bikouchochiku] famine-relief fund