We present a new class of efficient models for water flow in shallow aquifers, providing an alternative
to the classical but less tractable 3d-Richards model. Those models are tuned to have exactly the
same (dominant) behavior than the 3d-Richards model when the ratio ε =thickness over longitudinal
length of the aquifer is small. Thanks to a formal asymptotic analysis when ε → 0, those dominant
components of the flow are obtained in several time-scale situations.
The new class of models are then proposed, followed by their numerical approximation.
