The upper and middle reaches of the latter three rivers were not included in the plan because of their higher topography and comparatively low population at the time.
三河的上游因地勢較高，發生水災的機會少，加上民國五十八年訂防洪計畫時，那裡的居民不多，防洪經費也不如今天充裕，就沒有列進去。