Ecologically Significant Land

Ecologically Significant Land in the Saint Louis Region

With a grant from the Missouri Department of Conservation, Great Rivers Habitat Alliance undertook an analysis of properties in the Saint Louis region near rivers and other wetlands. The goal of this study was to identify parcels in St. Charles, St. Louis, Lincoln, and Pike counties as well as the city of St. Louis that are ecologically significant. The following section explains the multivariate analysis used to determine each parcel’s ecological significance ranking.

Parcel Ranking System

All of the datasets listed below are ones that have been designated as important factors when considering which parcels are more valuable than others for targeting for purchase. A parcel receives points if any part of it overlaps with any of the datasets listed below, excepting those in the “Proximity” category. Parcels must either be adjacent to or within a certain distance of the datasets in Proximity category in order to be awarded points (see below for details). Since some of the factors are more important than others, a parcel may receive a different number of points for overlapping different datasets. The datasets are split into 5 different categories based on their importance, and each dataset within a category contributes the same number of points to any parcel that overlaps it.

For example, a parcel may overlap wetland, 100 year floodplain, and designated Candidate Ecological Restoration Area, as well as be within 0.5 miles of a road. Since wetland and 100 year floodplain are both in the Primary Ecologically Important category, they each contribute 3.5 points to the parcel’s ranking, giving it 7 points. Candidate Ecological Restoration Area is in the Areas of Investment category and therefore contributes 2 points to the parcel’s score, bringing its score to 9 points. Road access (or being within 0.5 miles of a road) gives the parcel 1 additional point, bringing its final score to 10 points. Each parcel’s score is calculated in this manner, adding points for each dataset/factor that it overlaps with, and the total score being its final ranking.

The percentage of overlap is not taken into consideration. A parcel may only slightly overlap one of the datasets while another overlaps the same dataset entirely, and both parcels would receive the same number of designated points.

The following is the list of datasets used to rank the parcels, including which category of importance they fall into, and how many points they contribute to any overlapping parcel:

1. 1. Primary Ecological Factors (4 points each)
      1. Wetlands
      2. 100 Year Floodplain
   2. Secondary Ecological Factors (3 points each)
      1. Riparian Areas
      2. 500 Year Floodplain
      3. Rare Ecosystems
   3. Primary Areas of Investment (2 points each)
      1. MoDOC Conservation Opportunity Areas (COA)
      2. Army Corps Endangered Species Areas
      3. EPA Candidate Ecological Restoration Areas (CERA)
      4. EPA Potentially Restorable Wetland on Agricultural Land – High Potential (PRWAL_High)
      5. Audubon Important Bird Areas (IBA)
      6. FEMA Floodplain Areas of Special Consideration (FASC)
   4. Secondary Areas of Investment (1.5 points)
      1. EPA Potentially Restorable Wetland on Agricultural Land – Moderate Potential (PRWAL_Med)
   5. Proximity and other Ecological Factors and Areas of Investment (1 point each)
      1. Proximity:
         1. Park Adjacency (parcel touches park or other government-owned land)
         2. Road Access (parcel is within 0.5 miles of a road)
         3. Boat Access (parcel has a boat ramp/access point)
      2. Ecological Factors:
         1. FEMA Areas with Reduced Flood Risk Due to Levee (RFR)
      3. Areas of Investment:
         1. EPA Potentially Restorable Wetland on Agricultural Land – Low Potential (PRWAL_Low)

This ranking results in scores ranging from 0 (least ecologically significant) to 32.5 (most ecologically significant). Government lands are excluded from this analysis and, therefore, colored green in the following maps.

Documents:

1. Ecological Significant Land in the St. Louis Region
2. Parcel Ranking for Eastern Half of Lincoln County (Excel)
3. Parcel Ranking for Pike County (Excel)
4. Parcel Ranking for St. Louis City (Excel)
5. Parcel Ranking for St. Louis County (Excel)