diversion level can be pre-regulated according to the existing diversion capacity of each floodplain. If this allowance is not exceeded, a regular diversion cost can apply; however, if it is exceeded, this will then means a surplus for diversion associated with economic penalties and/or expansion costs. Penalties can be expressed in terms of raised operation costs for flood diversion and/or destruction of land-based infrastructure. Expansions of floodplains can help increase the allowable flood diversion levels and thus reduce penalties. Thus the total diverted flow is the sum of primal allowance, incremental quota, and probabilistic excess flows.