ails ) ▁to ▁cross es , ▁gates , ▁h ing es , ▁even ▁can non ▁for ▁mission ▁defense . ▁Iron ▁in ▁particular ▁was ▁a ▁comm od ity ▁that ▁the ▁mission ▁acquired ▁sole ly ▁through ▁trade , ▁as ▁the ▁mission aries ▁had ▁neither ▁the ▁know - how ▁nor ▁technology ▁to ▁mine ▁and ▁process ▁metal ▁or es . ▁ ▁No ▁study ▁of ▁the ▁miss ions ▁is ▁complete ▁without ▁mention ▁of ▁their ▁extensive ▁water ▁supply ▁systems . ▁Stone ▁z an jas ▁( aqu ed uct s , ▁sometimes ▁sp anning ▁miles , ▁brought ▁fresh ▁water ▁from ▁a ▁nearby ▁river ▁or ▁spring ▁to ▁the ▁mission ▁site . ▁Open ▁or ▁covered ▁l ined ▁d itch es ▁and / or ▁b aked ▁cl ay ▁pip es , ▁joined ▁together ▁with ▁l ime ▁mort ar ▁or ▁bit umen , ▁gravity - f ed ▁the ▁water ▁into ▁large ▁c is tern s ▁and ▁f ount ains , ▁and ▁em pt ied ▁into ▁water ways ▁where ▁the ▁force ▁of ▁the ▁water ▁was ▁used ▁to ▁turn ▁gr inding ▁whe els ▁and ▁other ▁simple ▁mach in ery , ▁or ▁disp ensed ▁for ▁use ▁in ▁clean ing . ▁Water ▁used ▁for ▁drink ing ▁and ▁cook ing ▁was ▁allowed ▁to ▁trick le ▁through ▁alternate ▁layers ▁of ▁sand ▁and ▁char co al ▁to ▁remove ▁the ▁imp ur ities . ▁One ▁of ▁the ▁best - pres erved ▁mission ▁water ▁systems ▁is ▁at ▁Mission ▁Santa ▁Barbara . ▁ ▁History ▁▁ ▁Begin ning ▁in ▁ 1 4 9 2 ▁with ▁the ▁voy ages ▁of ▁Christopher ▁Columb us , ▁the ▁Kingdom