in the latter case of instream habitat regulations are intended to maintain minimum streamflow requirements throughout the year in the model presented here we will consider the design of policies to address cumulative stream depletion problems in some detail kuwayama and brozovic extension of the model to allow maintenance of specific streamflow constraints continuously throughout the year requires an intraseasonal crop water production function which leads to much more complex analyses and is generally not analytically tractable eg han thus the impact of ongoing pumping on streamflow needs to consider the pumping history rather than just pumping in the current period