The work presented here describes a new modeling infrastructure of irrigation which is integrated in a land surface model and which will make this model a suitable tool for studies of interactions between irrigation water use and climate change. The model is presented and validated off-line over the Indian Peninsula. Numerical experiments are conducted with a 1 degree spatial resolution land surface model. Two 2-year simulations, forced by the ISLSCP (1987--88) data sets, are conducted with and without irrigation. The analysis focuses on irrigation modeling validation and briefly presents first results on irrigation's impact on the surface fluxes.