  We introduce an external control to reduce the size of avalanches in some
sandpile models exhibiting self organized criticality. This rather intuitive
approach seems to be missing in the vast literature on such systems. The
control action, which amounts to triggering avalanches in sites that are near
to be come critical, reduces the probability of very large events, so that
energy dissipation occurs most locally. The control is applied to a directed
Abelian sandpile model driven by both uncorrelated and correlated deposition.
The latter is essential to design an efficient and simple control heuristic,
but has only small influence in the uncontrolled avalanche probability
distribution. The proposed control seeks a tradeoff between control cost and
large event risk. Preliminary results hint that the proposed control works also
for an undirected sandpile model.
