Here are a couple of excerpts:
4.1.4 Ornamental water feature - Builders shall not install or facilitate the installation of ornamental water features.
Definitions
Ornamental water feature - Includes fountains, ponds, waterfalls, man-made streams and other decorative water-related constructions provided solely for aesthetic or beautification purposes.
From their cover letter at <http://www.epa.gov/watersense/docs/home_coverletter508.pdf>:
EPA welcomes your input on the draft Water-Efficient Single-Family New Home Specification. All interested parties are encouraged to review the draft specification and provide written comments by July 21, 2008. Written comments on the draft specification and ideas on a possible future revision to include more stormwater management criteria should be directed to watersensenewhomes@ erg.com. All comments become a part of the public record.
If you have any questions about the program, please contact John Flowers at (202) 564-0624 or flowers.john@epa.gov, or the WaterSense Helpline at (866) 987-7367. We look forward to receiving your feedback on the specification, as well as your organization's future participation with WaterSense.
Another document that may be of interest is Water-Efficient Single-Family New Home Specification Supporting Statement.