The invention discloses a combined
system underground initial rainwater
storage tank. The
storage tank comprises a
natural water drain unit and a buffering storage unit which are arranged in the
water flow direction and communicated. The
natural water drain unit comprises a first buffering tank and a first automatic water power gate arranged in the first buffering tank and normally closed. A water inlet
pipe is arranged on the upstream of the first automatic water power gate in the first buffering tank, and a
natural water drain opening is formed in the downstream of the first automatic water power gate. The buffering storage unit comprises a second buffering tank communicated with the first buffering tank and an
underground storage tank. The second buffering tank and the
underground storage tank are communicated through a second automatic water power gate normally closed. On the premise of ensuring the maximum treatment capacity of a
sewage treatment
plant, initial rainwater is collected into the
storage tank, later-stage rainwater is drained to natural water,
pollution caused by direct drainage of the initial rainwater and overflow
pollution can be effectively prevented, and the initial rainwater storage tank is simple in structure, low in cost, and capable of being controlled automatically without manual operation, and stores the rainwater safely and reliably.