This  study  is  on  rainwater  harvesting  for  water  conservation  in  University  of  Maiduguri where  both primary and secondary  data were  used. Rainfall data was obtained from Nigerian  Metrological  Agency  (NIMET),  and  rainwater  was captured,  directed  and collected  in  a  research  reservoir  using  U-shaped gutters  and  4”PVC  pipes,  45°  and  90° elbows and “tees”. The water harvested per rainfall  event was gauged using a dipping stick calibrated at 10cm. The water collected using the  research reservoir in  the  month of  July  alone  (9850.1  liter  per  day)is  157602 liters  can  be  used  in the  building  for  over  a year  which  is  about  128%  of  the  water  used.  This  is  because  the  water  requirement  by  the building  is  just  about  561  liters  per  day  which  is  equal to  123420  liters  annually. Meanwhile, the  estimated  water harvested  using  half  the  roof  of  the,  that  is  9125.2  liters per day is  547513.3 liters  annually. This water can be used in  the  building for  about three  years and four months. Having considered the month with highest rainwater 3 harvested (227168.4liters), and 8m x 7m x 5m = 280m (280000 liters) capacity reservoir can  contain  the  water  harvested  since  the water  is  going  to  be  used  as  it  is  captured.  With good arrangement of the  rainwater harvesting system and adequate reservoir that  can contain  the  annual  rainfall  from  the  roof  of  the  new  Geography Complex, the  rainwater captured from  the  roof  of  the  building  can  serve  the  water  need  of  the  office  complex  and even  beyond.  The  study recommends  that:  Building  plans  should  have  roofs  with  gutters of  same  materials  as  the  roof  so  as  to  encourage rainwater  harvesting  without compromising  the  aesthetic  value  of  buildings,  all  institutions  and  houses  (public  or private) with large buildings should  be constructed with facilities needed  for  harvesting rooftop  rainwater ,  so  as  to  reduce water  scarcity,  conserve  water and  the  entire ecosystem, further  research should be conducted on the quality of water harvested and the various uses  the  water can be effectively put to.

KEYWORDS:  Rainwater  harvesting,  conservation,  rooftop,  rainfall,  reservoir