Cold water can depress rice yields.
At high elevations in Nepal, farmers re-route cold water from the main valley rivers to raise the water temperature before irrigation so as to induce earlier flowering and timely maturation of their rice cultivars (Rana et al. 2000).
From Ecosystems and Human Well-Being: Policy Responses: Findings of the Responses Working Group (Millennium Ecosystem Assessment) page 148.
In California, after a dam cooled down their irrigation water and a lengthy negotiation, a handful of rice growers will get:
anywhere from $1 million to $3 million a year, depending on the price of rice
From Department of Water Resources warms up to rice growers’ needs.
You figure it out; I can’t. Via.