"Those plans will eliminate any feedlots that don't comply, or pollute ... Some of them it will significantly change how they operate, and some are already operating in a compliant and sensible way."
Feedlot farming, which involves concentrating stock into small areas and feeding a combination of roughage, grains and vitamins, is often criticised by animal welfare groups and environmental organisations.
Movement is restricted to encourage weight gain and fat distribution throughout muscle tissue. This marbling is desirable to some consumers.
Mr Graham said the current system of feedlot farming, particularly the disposal of effluent, must change for the sake of the natural environment.
The Organic Farm's Andy Tait-Jamieson said only a handful of beef export farmers run feedlot in the winter.
"The wagyu beef is the one that is mostly feedlot, because that's how the Japanese like their meat. [It's the] marbled fat through the actual protein meat itself."
He said the domestic market for marbled beef is small.
Mr Graham was confident even if the number of farmers running feedlot in winter increased if the dam goes ahead, the strength of the regulations in Plan Change 6 would be enough to mitigate harmful environmental effects.
However Fish & Game New Zealand said the long-term effects of feedlot farming are not fully known and therefore the practice is an environmental gamble.
"I doubt that you could get strong enough regulation, because the impacts are drawn out over such a long time period," said chief executive Bryce Johnson.
"Urine in particular, going into the ground. Where that ends up, there's a lot we don't know about aquifers, under our alluvial plains.
"It compacts the soil and breaks it down, if you get a rain event you get a lot of sediment run-off. Amongst the science community there's an increasing recognition that sediment is in fact ... a much bigger issue than we've been contemplating.
"There are a lot of unknowns of just how environmentally sustainable feedlots could be."
He said it would be expected that Mr Graham backed his own council's plan.
"Some of these things shouldn't even happen until we can be a lot more certain that some of these things can be run in an environmentally sustainable way, and at the moment I doubt we can say they could be."