Beginning from analyzing the origin and crux of the flood of Huaihe River

6 principles summarized from the experience during last 50-years history are referred. They are demand principle

coordination principal

unified management principle

investment principle

law and regulation principle and scientifically harnessing principle. Some engineering and non-engineering methods are also discussed in the paper. Harnessing Huaihe River in this paper means controlling the river according to the natural law of water

promoting its benefit and abolishing its harm at the same time. Combining harnessing Huaihe River with developing

i.e.

saving water and increasing the sources

balancing the use and protection

4 systems have been established step by step in about 20 years for Huaihe River. The systems are the drought and flood mitigation system adapting to natural ecological environment

the water protection system maintaining good ecological circulation

the optimal water allocation system supporting sustainable development and the water conservancy system agreeing with market economy. The plan of harnessing Huaihe River is the plan to construct and operate Huaihe River system. The construction and operation must conform to both natural ecological law and social development law

make most benefit from their interaction and cooperation

and realize the harmonic coexistence between human and nature. Then the ecological benefit can integrate the economic benefit with the social benefit.