Extensive Air Showers (EAS) induced by cosmic ray particles of very low energies due to the very steep cosmic ray energy spectrum dominate the secondary particle flux measured by single detectors and small shower arrays. Such arrays connected in extended networks can be used to search for potentially interesting spatial correlations between showers, which may shed new light on the nature of ultra high-energy cosmic rays. Quantitative interpretation of showers recorded by small local arrays requires a different methodology than that used by ordinary big EAS arrays operating in the ’knee’ region and above. We present ’small EAS generator’, semi analytical method for integrating cosmic ray spectra over energies of interest and summing over mass spectra of primary nuclei in arbitrary detector configurations. Results on the EAS electron and muon fluxes and particle density spectra are given.