Description: Contains watershed boundaries for at risk lakes in Maine, based on USGS 1:24,000 scale topography. Also contains direct drainage areas for the at risk lakes. The field "WSType" defines whether the watershed is a total or direct watershed. The direct drainage of an at risk lake includes all surface waters draining through the lake not influenced by biological processes occuring within other lakes upstream of the at risk lake. The direct drainage of a lake was defined using the following criteria:1. All ponds and lakes with a flushing rate greater than 50 times per year were included in the direct drainage.2. Ponds and Lakes without flushing ratesa. Greater than 10 acres in size were excludedb. Less than 1 acre were includedc. Between 1 and 10 acres were exlcuded: where DEP staff had previously defined a watershed delineation for upstream lakes; where MIDAS numbers had been assigned to upstream ponds; where the upstream lakes had very small watersheds with little to few incoming streams; where National Wetlands Inventory defined them as ponds (UB).d. Between 1 and 10 acres were included where the professional judgement of DEP staff, informed by aerial photography and National Wetlands Inventory data, deemed the waterbody to flush more than 50 times a year.
Service Item Id: 9cec1d6ba3b940e1961fa719c5d27dac
Copyright Text: Ben Tyler
Maine Department of Environmental Protection
Description: A draft collection of the Direct Watersheds of Urban Impaired Streams listed in Chapter 502. This layer is not yet complete. Delineations include field delineations, 2' contour and 20' Topo derived watershed delineations.
Description: This layer contains watersheds for these listed waters. The watersheds were delineated using a variety of methods including the following: field determined delineations, computer based delineations using ArcGIS with 20' contours, and scripted watershed delineations using 10M digital elevation models. Topology was run on combined watersheds to match edges. Where the boundaries touch the hand delineated were used as the correct boundary line.
Service Item Id: 9cec1d6ba3b940e1961fa719c5d27dac
Copyright Text: Prepared by the Maine Department of Environmental Protection 2005 through 2012. Compiled into a single layer 2012.