( ( Since ( ( the start ) ( of ( its operations ) ) ) ) ( , ( ( the reservoir ) ( ( ( has not ) ( ( reserved water ) ( for ( ( long periods ) ( of time ) ) ) ) ) . ) ) ) )
(ROOT (S (PP (IN Since) (NP (NP (DT the) (NN start)) (PP (IN of) (NP (PRP$ its) (NNS operations))))) (, ,) (NP (DT the) (NN reservoir)) (VP (VBZ has) (RB not) (VP (VBN reserved) (NP (NN water)) (PP (IN for) (NP (NP (JJ long) (NNS periods)) (PP (IN of) (NP (NN time))))))) (. .)))
Since the start of its operations, the reservoir has not reserved water for long periods of time.
(ROOT (S (NP (DT A) (NN reservoir)) (VP (VBZ is) (NP (NP (NN part)) (PP (IN of) (NP (NP (DT a) (NN cycle)) (SBAR (WHNP (WDT that)) (S (VP (VBZ holds) (NP (NP (DT an) (NN element) (CC or) (NN water)) (PP (IN for) (NP (NP (DT a) (JJ long) (NN period)) (PP (IN of) (NP (NN time))))))))))))) (. .)))