P2.3: Designate and Communicate VSPZs

(Required)

INTENT

Maximize the benefits of ecosystem services by designating and communicating to project team members a site development plan that protects healthy vegetation, soils, and sensitive environmental features.

REQUIREMENTS

• Identify, map, and protect critical and sensitive existing on-site features in Vegetation and Soil Protection Zones (VSPZs).
• Ensure the section of the site maintenance plan (see O+M P8.1: Plan for sustainable site maintenance) is complete and describes the on-going management activities to protect the integrity of VSPZs.

Note: Not all sites will contain a VSPZ.

VSPZ Mapping Requirements

Refer to the table below for relevant prerequisites (required) that may have VSPZ implications:

Prerequisite #	Prerequisite Name	VSPZ Requirement
Context P1.1	Limit development on farmland Case 2: Sites with farmland soils	95 percent of all healthy soils designated as prime farmland, unique farmland, farmland of statewide importance, or farmland of local importance
Context P1.2	Protect floodplain functions Case 3: Greenfields within floodplain	90 percent of 100-year floodplain area
Context P1.3	Conserve aquatic ecosystems Case 2: Sites with naturally occurring aquatic ecosystems	Entire delineated buffer, according to aquatic ecosystem classification
Context P1.4	Conserve habitat for threatened or endangered species Case 1: Brownfields/previously developed sites Case 2: Greenfield sites	Full extent of identified habitat
Soil+Veg P4.1	Create and communicate a soil management plan	Healthy soils that will be retained in place—show VSPZs on SMP map

Refer to the table below for relevant optional credits that may have VSPZ implications. Only include those credits that the project intends to pursue:

Credit #	Credit Name	VSPZ Requirement
Soil+Veg C4.4	Conserve healthy soils and appropriate vegetation	Minimum of 50 percent of total site area containing healthy soils and appropriate vegetation
Soil+Veg C4.5	Conserve special status vegetation	One foot (0.30 meter) radius for each inch DBH for special status trees; for shrubs, perennials, see below
Soil+Veg C4.6	Conserve and use native plants	Percentage of existing native plants on site
Soil+Veg C4.7	Conserve and restore native plant communities	Percentage of existing native plant communities≥ 2,000 square feet (185.81 square meters)

• VSPZs can encompass one plant or can include several plants in a group.
• VSPZ boundaries for trees should extend out from the trunk, to a minimum distance of a one foot (0.30 meter) radius (measured at ground level) per inch (2.54 centimeters) of diameter at breast height (DBH) or the full lateral extent of the actual root system as determined by ground-penetrating radar or by using the Clark-Matheny method (see the Resources section).
• VSPZ boundaries for shrubs should extend out from the stem to twice the radius of the shrub.
• VSPZ boundaries for herbaceous vegetation should extend to encompass the diameter of the plant.

VSPZ Requirements:

• Soils and vegetation within VSPZs must not be disturbed or compacted during construction.
• Management activities within VSPZs must not reduce the function and resiliency of wetlands or aquatic ecosystems.
• Invasive species present within VSPZs must be treated using equipment that can be carried in and out of the zone on foot or will not otherwise detrimentally affect soil compaction.
• Only minimal impact site development is allowed within VSPZs. No more than 10 percent of the total area of all VSPZs can contain minimal impact site development.
• Construction impacts from overall site development must not decrease the capacity of VSPZs to support the desired vegetation. For example, construction activities outside of a VSPZ should not change drainage patterns and microclimate effects within the VSPZ.
• Protect VSPZs from equipment parking and traffic, storage of materials, and other construction activities with a fence or other physical barrier that cannot be easily moved. (Use a wildlife-permeable barrier as appropriate).
• Communicate the locations and protective measures of VSPZs to construction and maintenance personnel. Outline consequences to contractors if they do not respect VSPZ boundaries.

RECOMMENDED STRATEGIES

• The number of roadways crossing through VSPZs should be minimized and constructed only when necessary, such as when a significant portion of the site can be reached only by crossing a VSPZ.
• Structures that must cross a VSPZ should be designed to minimize their impact on terrestrial and aquatic habitat connectivity.
• Additional planting within VSPZs must be done with care, because tree roots typically are located at the surface (sometimes to a depth of 2 to 3 inches, or 5.08 to 7.62 centimeters, at most).
• Perennial plantings within VSPZs should be done manually and without power equipment.
• Annual plantings are strongly discouraged within VSPZs.
• Additional planting within the one foot (0.30 meter) radius per inch (2.54 centimeters) DBH should be avoided. Planting here runs a high risk of damaging tree roots and soil chemistry and creating negative impacts due to excessive irrigation.
  • Planting should be limited to 25 percent of the area under the tree canopy or the area within a one-foot (0.30 meter) radius per inch (2.54 centimeters) DBH and must be done in consultation with a certified arborist or other appropriately qualified professional.
• Protect the root zone of trees found on site.
  • Try to protect groups rather than individual trees.
  • Design utility access away from the soil and roots of trees.
  • Reduce the need for utility trench work through strategic placement of utilities.
  • Where utility trench work is necessary, use air excavation to expose tree roots without damaging them (according to ANSI A300 Part 5).
  • If applicable, consider using directional boring technology (e.g., “mole,” “Ditch-Witch”).
  • For trees, ground-penetrating radar (GPR) or air excavation can be used to determine the location of tree roots.
• Consult with local experts qualified in plant health and safety to determine recommended special protection measures.
• Minimal impact site development should not require power equipment or wheeled vehicles and should not go beyond the necessary footprint of construction activity. Low impact construction is critical and essential to maintaining the integrity of VSPZs (e.g., construction attributes such as concrete slab foundations are strongly discouraged, permeable surfaces rather than impervious are strongly encouraged).

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