Kansas 1:24K Digital Elevation Model (DEM): 30m interval - Available from DASC Kansas GeoDatabase under Elevation.
Kansas 1:24K Hydrography - Available from DASC Kansas GeoDatabase under Water Resources.
The National Map Seamless Data Distribution System - Links to National Elevation Dataset (NED), National Land Cover Dataset (NLCD) and more.
USGS National Land Cover image files (modified NLCD) - Gridded 30-m pixels for individual states of conterminous US; data nominally for 'leaf-off' period, 1992. ~2.6 million discreet water bodies.*
US Census Bureau inland water bodies, 'Topologically Integrated Geographic Encoding and Referencing' (TIGER) shape files. Data collected from county data. ~75,000 discrete water bodies. The url cited by Smith et al. 2002 is no longer available. It looks like year 2000 data may be downloaded from http://www.esri.com/data/download/census2000_tigerline/ and/or http://www.census.gov/geo/www/tiger/index.html *
1998 National Inventory of Dams (NID), maintained by US Army Corps of Engineers. Tabulated geographic coordinates (points) for ~75,000 artificial dams across the US.*
Water features data layer from National Atlas (NA) data clearinghouse shape file. Polygons collected by USGS from hydrography layer of 1:2,000,000 digital line graphs (DLGs). ~5000 discrete water bodies.*
US Geological Survey digital line graphs (DLGs). Hydrography layer (polygons) of USGS 1:24,000 DLGs. ~ 9 million discreet water bodies.*
* = Water body datasets analyzed by (or updated from those analyzed by) Smith et al. (2002) for conterminous US.
Also see the Ponds Links page.