Description: To compile these data, compensatory mitigation maps from Army Corps permit files were digitized by manually scanning paper copies or using electronic versions. Attribute data were collected and interpreted by Regulatory Division staff by searching Department of the Army (DA) permit files, including mitigation plans and mitigation monitoring reports. Due to variances in mitigation mapping formats and changes in the regulatory program requirements over time, for some cases, some data elements were extrapolated or assumptions were made based on the best available information in the file. Regulatory staff then identified geographic control points on the digitized maps and mitigation polygons were numbered to correspond with submitted attribute metadata. In some cases, applicants provided GIS data that could be incorporated directly into this overall GIS data layer.Following compilation of the data, digitized mitigation maps were submitted to GIS professionals to map by hand (or merge, if submitted in GIS format) within ESRI ArcMap. GoogleEarth was used to geographically locate many of the sites. A geographic basemap was uploaded from ESRI and in most cases ESRI World Imagery WGS 1984 Mercator Auxillary Sphere was used with coordinate system NAD83 (http://www.arcgis.com/home/item.html?id=10df2279f9684e4a9f6a7f08febac2a9). Topography and other physical features were used to visually locate the boundaries of each polygon for accurately placing mitigation sites in geographic space.Following GIS mapping of the mitigation sites by GIS professionals, the sites were individually reviewed for mapping errors, overlapping polygons, or discrepancies, also using basemap ESRI World Imagery WGS 1984 Mercator Auxillary Sphere. In some cases DA permit files were reviewed again to obtain more information about mitigation polygons or attribute data. In addition, ArcMap tools were used to eliminate overlapping polygons, using either Erase/Replace, Integrate, Eliminate, or Manual Adjustment. See Mitigation Quality Assurance Quality Control (QAQC) Procedures.After GIS mitigation maps were completed in ArcGIS, the Operations & Maintenance Business Information Link (OMBIL) Regulatory Module version 2 (ORM2) database was queried to output a report for all the mapped projects. These additional attribute data were then joined to the mitigation map attribute data using a common field (‘DA-number’).Data range: The LAD Regulatory program began compiling mitigation map data for sites in Southern California and Arizona in 2011 for years 2009-2010 resulting in about 114 Permittee Responsible compensatory mitigation maps, resulting in a fairly complete dataset for mitigation permitted across the 2009-2010 time range. In 2012, data was compiled from years 2011-2012, resulting in a near complete dataset. In addition, paper files dating back to the 1990s to about 2006 are sorted annually and any projects appearing to have required compensatory mitigation are set aside and mapped. Therefore not all pre-2009 mitigation sites have been mapped nor do we expect to map all pre-2009 sites.Disclaimer: These mitigation data are not a comprehensive list of all Corps-approved permittee-responsible compensatory mitigation sites for the Los Angeles District. These data are not to be used for official compliance, enforcement, or legal matters. A data point or polygon may represent one or more DA files. A mitigation site may or may not have been implemented, or implemented in full, and may or may not be an active or completed mitigation site. Mitigation success criteria are evaluated based on the permit conditions and on-site inspections and not the maps or map features provided (including the shape, size, acreage, placement, or attribute data). A mitigation site may not be fully representative of the actual mitigation site nor is it a substitute for the areas provided in the DA permit and Corps-approved mitigation plans.
Service Item Id: 717992b881b14c7bb1a7231d9ccbc5fe
Copyright Text: Author: U.S. Army Corps of Engineers, Los Angeles District, Regulatory Division, 915 Wilshire Blvd., Los Angeles, California 90017. Point-of-contacts: Daniel P. Swenson (Daniel.P.Swenson@usace.army.mil) 213-452-3414, Bonnie L. Rogers (Bonnie.L.Rogers@usace.army.mil) 213-452-3372. Data-mappers: Various Army Corps of Engineers staff. Software used: ESRI (Environmental Systems Resource Institute) ArcMap 9.3. and 10.1.