  In this paper we consider sandpile models and modify the drive mechanisms to
control the size of avalanches. The modification to the drive mechanism is
local. We have studied the scaling behavior of the BTW and Manna models. We
have found that the BTW model is more sensitive to the modification than the
Manna model. Furthermore we have assigned a cost function to each avalanche and
have found an optimum value for the modification to arrive at the lowest cost.
