Swimming Pools. The dataset contains polygons representing planimetric grates created as part of the DC Geographic Information System (DC GIS) for the D.C. Office of the Chief Technology Officer (OCTO). These features were originally captured in 1999 and updated in 2005 and 2008. The following planimetric layers were updated using 2008 imagery - Grates (GratePt) - Bollards (BollardPt) - Stairs (StairPly) - Pools (SwmPoolPly).