(1) The numbering or index system used to identify specific waters of New York State was adapted from that used by the New York State Conservation Department in its biological survey series of reports on the watersheds of the State. The primary waters of a drainage basin, such as rivers or large lakes are usually referred to by name or an abbreviation. Tributaries of primary waters are consecutively numbered progressing upstream from the mouth. Ponds and lakes are numbered consecutively as they are encountered, such numbers being preceded by the letter P. Tributaries of such lakes and ponds are numbered consecutively as they enter, progressing clockwise around the lake or pond from its outlet or mouth. When isolated lakes and ponds are referenced by a waters index number, it is merely for convenience of their identification and location within a subdrainage basin, and it is not necessarily indicative of their being tributary to any waters to which no surface connection is shown on the reference maps.

(2) This system was applied to the basin under consideration by the Conservation Department in its biological survey of the Lower Hudson watershed in 1936, and has been closely followed in connection with the identification of the waters with the following exceptions: some of the stream numbers do not run consecutively due to the omission of streams originally shown on older maps employed by the Conservation Department at the time of its 1936 survey, but not shown on newer maps reproduced herein. Conversely, a few streams not shown on the older maps but appearing on the newer maps are designated by the letters a, b, c, etc.

(3) The system as applied to the identification of waters in the Lower Hudson River drainage basin may be illustrated as follows: