Watershed Restoration Suitability & Equity Mapping Tools


Watershed Restoration Suitability & Equity

The Department of Environmental Protection is dedicated to improving stream health and water quality. With a county as diverse as Montgomery, our department strives to foster strong partnerships with communities and continue to evaluate our processes to address innovation and equity in our watershed planning and design. Our focus is cleaner water and restoring ecosystems naturally for our entire community.

DEP Biomonitoring TeamProgram Goals

  • Satisfying regulatory requirements ( MS4) such as required pollution reductions ( TMDLs)
  • Achieving biological uplift
  • Protecting existing stream restoration projects
  • Assessing equity in project selection
  • Striving to make communities more livable

Assessing Suitability

DEP utilized a suitability modeling exercise to prioritize areas where pursuing restoration projects best align with the Department’s goals. This involved a high-level spatial analysis of the County and multiple data layers to determine areas with the highest suitability for restoration and locations where the department may pursue projects.

Data Analysis

Biomonitoring Data CollectionData analysis included factors such as stream habitat and biological conditions, presence of existing stormwater management, and pollution reduction requirements among many other layers of data. Through the analysis, factors were ranked, weighted, and normalized. The suitability “scores” for the specific maps were developed based on this ranking process.

Two maps-- stormwater management suitability and stream restoration suitability--were created at the completion of the modeling exercise and are designed to guide the department’s restoration efforts by aligning them with the program goals. This also provides the public the ability to transparently see where restoration efforts are being focused.

A third map-- equity assessment--was created to ensure equity is factored during the project selection process and throughout implementation.  This map was not a part of the watershed suitability data analysis but gives the department the ability to cross reference area suitability scores with demographic index scores and ensure project selection is not biased.

The suitability models will be used as a basis to pursue more detailed site level analysis and future planning evaluation. The maps also represent opportunities for coordinated partnerships with others to meet complementary restoration goals.




Stormwater Management Suitability Map

Stormwater Management Suitability Map
The stormwater management suitability map prioritizes areas that have little/no existing stormwater management, poor stream conditions, high amounts of impervious surfaces, flow to existing stream restoration projects, and require significant TMDL pollutant reductions. Spatial data is weighted, combined, and the resulting map prioritizes areas where DEP can focus on installing upland stormwater management.  A ranking was established and suitability scores were split into categories based on the distribution of low (32-73), medium (74-99) and high (100-130).

Map:  Stormwater Management Suitability


Stream Restoration Suitability Map

Stream Restoration Suitability Map
The  stream restoration suitability map prioritizes areas where selecting a stream restoration project would have a higher likelihood of improving biology and ecosystem function, significant levels of TMDL pollutant reductions and has less areas of unmanaged stormwater to maximize long term success and stream stability.

This map prioritizes the most suitable areas for the County to pursue stream restoration projects and strives to set realistic achievable goals in very distressed watersheds. A ranking was established and suitability scores were split into categories based on their distribution of low (7-17), medium (18-21) and high (22-23).

Map:   Stream Restoration Suitability


Equity Assessment Map

Equity Assessment Map
The  equity assessment map is a means for the department to ensure equity is factored during the project selection process and throughout implementation. This map utilizes American Community Survey data from the 2019 version of the  US EPA EJSCREEN* for census block groups in the County. By utilizing this data and determining the demographic index percentile of an area, the department can assess equity during the project selection process.

For example: Data for a census block group located in the Sligo creek watershed indicates the population in that block group is 54% people of color and 12% low income. Averaging these percentages results in a demographic index of 33%. This percentage is then compared to all the census block groups that exist within Montgomery County. Doing so, places this census block group in the 52nd percentile of the County. This equity assessment is split into 3 categories: low (0-33%), medium (34-66%) and high (67-100%). This provides the ability to cross reference percentiles with project suitability to ensure project targeting is not biased.

*For the purposes of this mapping, the term people of color is used to better reflect and depict the diversity exhibited across Montgomery County rather than the term “minority” which is used in the US EPA EJSCREEN

Map:   Equity Assessment