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City of Seattle 2 ft contours derived from Lidar captured in 2021. Contour lines display at 2ft, 10ft and 50ft intervals dependent on scale. Lines have been smoothed and generalized for display and performance. Development Detail: This vector tile service includes topographic contour lines representing elevation at 2-foot intervals within the city of Seattle. The contours were derived from a bare earth - digital elevation model (DEM) with a pixel resolution of 1.5 feet. The lidar data that created the DEM were collected by NV5 Geospatial over the spring and summer months of 2021 and provided to the city by King County in 2022. The DEM used to generate the contours was filtered using the Focal Statistics tool in ArcGIS, which served to limit some abrupt changes in cell values. A 3x3 rectangular neighborhood analysis was applied and a mean value was calculated per raster cell. After running the Focal Statistics tool, 2-foot contours were generated from the filtered DEM. To reduce file size and improve performance, the contours were generalized further using the Smooth Line tool in ArcGIS. A smoothing algorithm type of Polynomial Approximation with Exponential Kernel (PAEK) and a smoothing tolerance of 20 feet was selected in the Smooth Line tool parameter options. Finally, after executing both generalization tools (Focal Statistics and Smooth Line), all lines less than 25 feet in length were omitted from the final output. Please note: The 2-foot contours are intended to be used for general reference and cartographic purposes only and should not be used for analysis purposes.

Layers of geospatial data include contours, boundaries, land cover, hydrography, roads, transportation, geographic names, structures, and other selected map features.

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Lidar Digital Elevation Models (DEMs) at 2-meter resolution have been used to derive watershed boundaries for the State of Maine. Geographic Information Systems (GIS) software was used to hydrologically enforce lidar DEMs and delineate watershed boundaries at pre-existing pour point locations (Price, 2016). The watershed boundaries are comparable in size to the 12-digit Hydrologic Unit catchments and have a 12-digit Hydrologic Unit Code (HUC12) identifier attribute field that has a one-to-one match with the national WBD dataset (https://www.usgs.gov/national-hydrography/watershed-boundary-dataset). This data release consists of a zip file containing an ESRI polygon shapefile (vector GIS dataset). This work was conducted in cooperation with Maine Department of Transportation and Maine Office of GIS. Curtis Price, 20160606, WBD HU12 Pour Points derived from NHDPlus: U.S. Geological Survey data release, https://www.sciencebase.gov/catalog/item/5762b664e4b07657d19a71ea

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,,305b Assessed River, Lake, Estuary 2022:,Connecticut 305b Assessed River 2022 is a 1:24,000-scale, line feature-based layer that includes rivers that have been assessed to comply with Sections 305(b) and 303(d) of the federal Clean Water Act. Section 305(b) of the Clean Water Act requires each state to monitor, assess and report on the quality of its waters relative to attainment of designated uses established by the State's water quality standards. Section 303(d) requires each State to compile a subset of that list identifying only those waters not meeting water quality standards and assign a Total Maximum Daily Load (TMDL) priority ranking to each impaired waterbody.,This layer is based on information collected and compiled prior to 2022. It represents conditions at a particular point in time and does not represent current conditions. This layer includes only rivers that were assessed in the time period above referenced. It can be used with the 2022 Connecticut 305b Assessed Lake layer and the Connecticut 305b Assessed Estuary layer to geographically display attainment and non-attainment for each designated use on assessed waters within Connecticut's boundaries.,Features are lines that represent the locations of assessed rivers. The sources for these features include the hydrography layer and the water quality classification layer. Attribute information is comprised of a unique identifier (segment ID) for each feature, the name of the waterbody, its location, the assessment cycle (year), the water type, the water quality class goal, the length of the feature in miles, the National Hydrography Dataset basin number, and the assessment for the following categories: aquatic life, recreation, fish consumption, and drinking water supply. Data is compiled at 1:24,000 scale.,Connecticut 305b Assessed Lake 2022 is a 1:24,000-scale, polygon feature-based layer that includes lakes that have been assessed in compliance with Sections 305(b) and 303(d) of the federal Clean Water Act. Section 305(b) of the Clean Water Act requires each state to monitor, assess and report on the quality of its waters relative to attainment of designated uses established by the State's water quality standards. Section 303(d) requires each State to compile a subset of that list identifying only those waters not meeting water quality standards and assign a Total Maximum Daily Load (TMDL) priority ranking to each impaired waterbody.,This layer is based on information collected and compiled prior to 2022. It represents conditions at a particular point in time and does not represent current conditions. This layer includes only assessed lakes. It can be used with the 2022 Connecticut 305b Assessed River layer and the Connecticut 305b Assessed Estuary layer to geographically display attainment and non-attainment for each designated use on assessed waters within Connecticut's boundaries.,Features are polygon l

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