We are working on an urban project which combines green roofs that partially infiltrate water and then evaportanspirate it, with a rainwater collection tank which captures the runoff from these green roofs and from the project´s hardscape (roofs, terraces, walkways at grade). The entire site is built below grade. The collected rainwater is stored and will be used for irrigation - however, the irrigation needs are low, and therefore many days would be needed in order to use all of the collected stormwater (more days than the local average timeframe between storm events). Is this still acceptable or does the team need to show that the collected rainwater will be used before any new rain events take place? Thanks for any guidance!