The MyLeftWing website has done some good background research on the Wazzani Springs, including this nugget from DEBKAfile, which is written by former (and current?) Israeli intelligence officers:
Perhaps the most important gain from the crisis is Israel’s recovery of control over its main sources of water, the Wazzani springs in the divided Ghajar village.
An article from 2003 discusses the Israeli threat to invade Lebanon over the Hasbani and Wazzani Rivers project, which was defended by PM Hariri, who was later assassinated.
A water-pumping station in southern Lebanon that Israel said could be grounds for war has been supplying parched villages near the border with Israel for three months…
…Lebanon, Mr. Hariri said, also wants to protect its water rights. “We asked the U.N., U.S., EU and Russia to help us in defining the quantity of water” that Lebanon can obtain from the Wazzani according to the international laws, Mr. Hariri said.
He told UPI he believes the status quo will continue. “Maybe the political situation in the region does not allow peace, but it does not mean that the alternative is war,” Mr. Hariri said. The Wazzani River flows for about two miles inside Lebanon before entering Israel.