Description: There are two important attributes in this GIS shapefile. The TMDLshed includes all of the lake, pond and tributaries subwatersheds modeled for the TMDL project. The Impaired_L identifies which TMDLshed is within the direct drainage area of one of the seven impaired lakes included in this TMDL project. TMDLsheds upstream of the impaired Silver Lake (included in a previous TMDL project) and unimpaired lakes (Round, Karth, and Johanna), are not part of an impaired lake direct drainage area.
Copyright Text: June 2, 2014
Meghan Jacobson, PhD
Limnologist
Emmons & Olivier Resources, Inc.
Description: MPCA water resource staff identified Total Maximum Daily Load (TMDL) and Watershed Restoration and Protection Strategy (WRAPS) project boundaries as a central data element for the agency. A team of staff from the MPCA Watershed Division and the MPCA Information Systems Office worked together to collect and store this data in a central repository and distribute it to MPCA partners as needed. The team designed a geospatial database, developed a user guide, and developed communication and distribution strategies for the database.The resulting geospatial database is maintained by the MPCA Watershed Division and polygons are included in the database for all EPA-approved TMDL/WRAPS projects. Where possible, polygons are taken from existing published geospatial data layers but new delineations can be included when necessary. Polygon boundaries typically follow hydrologic watershed delineations but in certain cases TMDL/WRAPS projects are defined by administrative boundaries, such as Watershed Districts or Watershed Management Organizations, especially in the Twin Cities Metropolitan Area. New polygons are added to the database using the ‘append’ [no_test] command in ArcGIS. Attribute information is added for each polygon including the organization that created the data, creation date, date submitted to MPCA, and a series of identification codes that allow the database to be linked to other MPCA databases. If a new revised polygon is added that replaces an older polygon for the same project, the older version is saved and coded as ‘inactive.’This new spatial database will give MPCA staff and external partners the ability to see the spatial extent of Minnesota TMDL/WRAPS projects in a GIS context. The database can also be used in spatial analysis operations with other spatial data layers that map features in the environment such as feedlots, surface water discharge locations, and riparian areas. The availability of this data should help to support collaboration between various organizations involved in water resource management and impaired waters issues in Minnesota.
Copyright Text: Minnesota Pollution Control Agency (MPCA)
520 Lafayette Road,
Saint Paul, Minnesota 55155
Description: There are two important attributes in this GIS shapefile. The TMDLshed includes all of the lake, pond and tributaries subwatersheds modeled for the TMDL project. The Impaired_L identifies which TMDLshed is within the direct drainage area of one of the seven impaired lakes included in this TMDL project. TMDLsheds upstream of the impaired Silver Lake (included in a previous TMDL project) and unimpaired lakes (Round, Karth, and Johanna), are not part of an impaired lake direct drainage area.
Copyright Text: June 2, 2014
Meghan Jacobson, PhD
Limnologist
Emmons & Olivier Resources, Inc.