Proposed is the use of a composition based on polyvinyl alcohol (component a) ) as a water-retention agent in mixtures comprising hydraulic binding agents, the component comprising a sulfonated ketone formaldehyde condensation product as a further component with a preferred mixing ratio of 1:1. The component a) may comprise, depending on the respective hydrolysis degree, polyvinyl acetate parts or parts of other polyvinyl esters as well as polymers in general, which can be converted into polyvinyl alcohol by hydrolysis, up to 90 wt.%. Said new composition is used as a water-retention agent in mixtures comprising hydraulic binding agents, and particularly in connection with the exploitation of underground crude oil and natural gas deposits.