According with the determinations of the Metropolitan Plan of Urban Regulations (PRMS), scale 1:250.000, all the river bed of Maipo River that cross the Maipo County was classified how a sector with flood high risk.

But, because the scale, the PRMS means generalizations related to risk level terrain classifications. So local authorities, considering internal differences into the river bed and inmediate fluvial terraces along it, ask for a investigation to determine the exact situation of this terrains.

A 1:2000 scale research was iniciated to satify the information requeriments for the establishment of the potential and restrictions soil use ordinance.

Using topographic maps, aerial fotographs and doing terrain surveys, joint with last decades statistical information of run off and the dimentions of the river bed (width and deep), the level of flood risk situation of the differents aluvial landforms was established, determining the restriction degrees to urban soil use or others meaning permanent settlement, and recomending some measures and alternatives.