Abstract: This coverage is a record of major lakes and reservoirs in the Pacific Northwest derived from 1:100,000 and 1:24,000 scale maps. A WaterbodyID is assigned to most polygon features and is the basic unique identifier used to georeference StreamNet lakes/reservoirs data. The waterbodyID was assigned at the state fish & wildlife agencies and the state lake coverages were then provided to the StreamNet regional office by: Oregon Dept of Fish & Wildlife - Jon Bowers (jon.k.bowers@state.or.us) Washington Dept of Fish & Wildlife - Martin Hudson (hudsomgh@dfw.wa.gov) Idaho Dept of Fish & Game - Bart Butterfield (bbutterf@idfg.state.id.us) Montana Dept of Fish, Wildlife & Parks - Jennifer Corbin (quietsister@qwest.net) These coverages were then combined into this regional coverage by: Regional StreamNet GIS Specialist(StreamNetGIS@psmfc.org) Purpose: Data is intended for use in a variety of applications. Limitations_of_Data: Data is collected at the 1:100,000 scale from the PNW Banks coverage and other sources and is considered complete at this scale. Additional lakes and waterbodies were then added from 1:24,000 scale maps and other miscellaneous sources but this data set should not be considered complete at the 1:24,0000 scale as not all features were included at this level of detail. Please note that different methods were used between the state agencies when adding 1:24,000 scale lakes so scale is not consistent between the states (ie. more lakes are shown in some states than in others). Entity_and_Attribute_Overview: Attribute Type Definition AREA Binary Fl.point Area of polygon in coverage units PERIMETER Binary Fl.point Perimeter of polygon in coverage units LAKES# Binary Integer Internal feature number LAKES-ID Binary Integer User-assigned feature number WATERBODYID Character Unique waterbody identifier (Longitude/Latitude ID) which consists of the longitude (first 7 digits) and latitude (last 6 digits) of the centroid of the polygon feature. (This follows the same format as the stream-based LLID - See http://www.streamnet.org/pnwr/PNWNAR.html for more information about the PNW Reach hydrography and LLIDs. NAME Character Name of the waterbody. Procedures_Used: WaterBodyID is assigned in a similar method to that used to assign LLIDs at the mouths of streams. For lakes and reservoirs, a centroid was derived from each polygon and the longitude/ latitude coordinates were ungenerated from this centroid. A unique waterbodyID was then derived by concatentating the first 7 digits of the longitude value and the first 6 digits of the latitude value (example longitude -117.4307 and latitude 43.4067 combined to make a waterbodyID of 1174307434067). Revisions: This is the 4th version of this coverage (made 6/14/01) Version 2: The first version was found to have errors in the linework and was revised in June, 2000, alleviating the previous linework problems and cleaning up overlapping polygons around the state boundaries to ensure only one shoreline polygon per lake/reservoir. Version 3: The third version was created to incorporate updated lakes information for Washington state which synchronizes the name and waterbodyID attributes with the Washington Dept of Ecology coverage and also adds some additional lakes not included with the previous version. Version 4: The fourth version incorporates lake and reservoir information for Western Montana. This information was extracted from the new MFWP coverage and appended and meshed along border areas with the existing coverage. Reviews_Applied_to_Data: Visual pass overview. Related_Spatial_and_Tabular_Data_Sets: PNW River Reach Hydrography Banks Coverage (spatial)-- This is the base 1:100,000 scale banks coverage used as a source for some of the 1:100,000 scale lakes and reservoirs. This data set is available for download from http://www.streamnet.org/pnwr/pnwrhome.html References_Cited: N/A Notes: N/A Currentness_Reference: Data is current as of 2001. Maintenance_and_Update_Frequency: Future enhancements (adding smaller lakes and reservoirs, more name and waterbodyID assignments) are possible but not currently scheduled. The current version of this dataset will be maintained at http://www.streamnet.org/gisdata.html Access_Constraints: N/A Data_Set_Credit: Data was provided by Washington Dept. of Fish & Wildlife, Washington Dept. of Ecology, Oregon Dept. of Fish & Wildlife, Idaho Dept. of Fish & Game, and Montana Dept. of Fish, Wildlife and Parks. Data was appended and compiled by the StreamNet project (http://www.streamnet.org). Completeness_Report: Complete data set. See "Limitations of Data" for limitations. Horizontal_Positional_Accuracy_Report: Not Available Vertical_Positional_Accuracy_Report: Not Available Cloud_Cover: N/A GIS Data Projection Info: PROJECTION LAMBERT UNITS FEET DATUM NAD27 SPHEROID CLARKE1866 1st Standard Parallel 42 20 0.000 2nd Standard Parallel 48 40 00 central meridian -117 00 0.00 lat org 41 00 0.00 easting 914401.82880 (in meters) northing 0.0