This parking lot is surfaced with permeable paving stone which differs from regular paving stone because the gaps between the paving stone units are wider than normal. Rainfall penetrates through the permeable paving stone surface and flows into a granular underground stone reservoir where it is then infiltrated into the underlying native soil. The permeable paving stone parking lot functions to reduce the amount of stormwater runoff leaving the site, improves the quality of that stormwater runoff, and serves to enhance the local groundwater regime.