The system used for locating wells and springs in this report is based on the rectangular system for subdivision of public land (see figure below). The State is divided into 36 square-mile townships numbered according to their location relative to the east-west Willamette baseline and a north-south Willamette meridian. The position of a township is given by its north-south Township position relative to the baseline and its east-west Range position relative to the meridian. Each township is divided into 36 sections approximately 1 square mile (640-acre) in area and numbered from 1 to 36.
For example, a well designated as 01S/03E-33DCA is located in Township 1 south, Range 3 east, section 33. The letters following the section number correspond to the location within the section; the first letter (D) identifies the quarter section WILLAMETTE MERIDIAN (160 acres), the second letter (C) identifies the quarter-quarter section (40 acres), and the third letter (A) identifies the quarter-quarter-quarter section (10 acres). Thus, well 33DCA is located in the NE quarter of the SW quarter of the SE quarter of section 33. When more than one designated well occurs in the quarter-quarter-quarter section, a serial number is appended.
For some wells that were field located during previous USGS and OWRD studies, a different system of letters following the section number was used for the location within the section (fig. 3). This system assigns a letter to one of 16 quarter-quarter sections (40 acres) that divide the section. The location 33DCA would correspond to the location 33Q. When more than one designated well occurs in the quarter-quarter section, a serial number is appended.