In allocating land for required common open space, the following hierarchy of primary and secondary open space applies.

1. Primary Open Space
   The following are considered primary open space areas and must be the first areas reserved as required open space:
   1. Floodway areas;
   2. Natural resource buffers required along primary and secondary watercourses (see open space bonus allowance in Sec. 9.2.3 A.1.d);
   3. Slopes above 25% of at least 5,000 square feet contiguous area;
   4. Jurisdictional wetlands under federal law (Clean Water Act, Section 404) that meet the definition applied by the Army Corps of Engineers; and
   5. Transitional protective yards.
2. Secondary Open Space
   The following are considered secondary open space areas and must be included as required open space once the primary open space areas are exhausted:
   1. Floodway fringe and/or future conditions flood hazard areas.
3. Tertiary Open Space
   The following are considered tertiary open space areas and must be included as required open space once the primary and secondary open space areas are exhausted:
   1. Historic, archeological and cultural sites, cemeteries and burial grounds;
   2. Significant natural features and scenic viewsheds such as ridge lines, field borders, meadows, fields, river views, natural woodlands that can be seen from roadways and serve to block the view of the project in whole or in part;
   3. Habitat for federally-listed endangered or threatened species;
   4. Individual existing healthy trees greater than 10 inches DBH and their critical root zones;
   5. Areas that connect to neighboring open space, trails or greenways;
   6. Soils with severe limitations due to drainage problems; and
   7. Tree conservation areas.