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MassDEP Updates BVW and Inland Wetland Replacement Materials

Posted on: April 25, 2023 - 11:40am

The Massachusetts Department of Environmental Protection has updated the Inland Wetland Replacement Guidelines, the Massachusetts Handbook for Delineation of BVWs, and the Bordering Vegetated Wetland Determination Form.

The following information was released by the Massachusetts Department of Environmental Protection:

The Inland Wetland Replacement Guidelines

The purpose of the update is to incorporate much-needed improvement to the Guidelines following a recent study by UMass Amherst and MassDEP (Jackson et al., 2018). The study concluded that the primary reason for unsuccessful wetland replacement projects was failure to establish appropriate wetlands hydrology. The revised guidance identifies common issues that lead to shortfalls and elaborates on ways to better assess hydrology, define success standards, and design replacement wetlands prior to construction. Specific updates and revisions to the guidelines include:

  • Section 2.2 – Replacement Site Selection / Feasibility Analysis. This section introduces the hydroperiod and hydrologic feasibility analysis to determine adequate site conditions. Pre-design site feasibility requirements correspond to the four types of wetlands in the Novitzski classification system. The feasibility study results will dictate what the design should include.
  • Section 4.0 – Monitoring (added sections). This Chapter now includes sections specific to monitoring hydric soils and hydrologic site conditions. Ultimately, the post-construction site conditions should align with the feasibility assessment results and the design.
  • Section 5.0 – Alternatives to Wetland Replacement. This chapter introduces alternatives to BVW replacement for variance and limited projects. When approved by the issuing authority, acceptable mitigation may include, but is not limited to: stream restoration, dam removal, and/or stream crossing replacement.
  • Minor changes throughout.

An initial draft of the manual was prepared and then reviewed by the MassDEP Wetlands Program Regional Office Section Chiefs and the Boston Office. Additional reviews were conducted by the Massachusetts Association of Conservation Commissions (MACC), Massachusetts Society of Municipal Conservation Professionals (MSMCP), and the Association of Massachusetts Wetland Scientists (AMWS). Following the rollout, MassDEP will partner with MACC to conduct up to four statewide full-day classroom/field workshops with a target audience of Conservation Commissions, other state agencies, consultants, and other applicants. The training events are currently being planned for late spring / early summer of 2023. An hour-long update summary will be provided during the MACC Annual Conference on March 9 at 4PM and later at a MACC Lunch and Learn Webinar (TBA). Both the Massachusetts Handbook for Delineation of BVWs and the Massachusetts Inland Wetland Replacement Guidelines will be covered in the update and trainings.

Massachusetts Handbook for Delineation of BVWs

The purpose of the handbook update is to incorporate the current state of the science and better align the Massachusetts method with the methodologies used by the US Army Corps of Engineers (USACE) in conducting wetlands delineations under the U.S. Clean Water Act. While Massachusetts retains its authority to conduct jurisdictional determinations in accordance with the Massachusetts Wetlands Protection Act, the scientific techniques presented in the USACE Regional Supplement (Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Northcentral and Northeast Region. v2.0. 2012) have valid applicability to help understand and evaluate vegetated wetland characteristics. The updated MassDEP Manual is intended to better align the two methodologies. Specific changes to the handbook include:

  • Massachusetts 2 plus-parameter approach (in addition to requiring hydrophytic vegetation and hydric soil as an indicator of hydrology for all sites, Other Indictors of Hydrology are also required for some sites and recommended for all sites)
  • Adopt federal classification of vegetative strata (i.e., the current Massachusetts methodology uses five strata, the new classification uses four strata by combining the sapling / shrub)
  • De-emphasize small observational plots for vegetation sampling and recommend the use of variable-size plots (i.e., these relatively larger plots avoid having to make decisions about the appropriate number and placement of smaller plots but require the delineator to estimate percent cover over a larger area)
  • Adopt federal hierarchy for vegetation analysis (Rapid, Dominance, Prevalence)
  • Reference the 2020 National Wetland Plant List: (i.e., the Wetlands Protection Act currently references the 1988 plant list. MassDEP is proposing a regulation revision to adopt the 2020 plant list. The Handbook will align with the proposed regulation change when it is promulgated).
  • Categorization of “Other Indicators of Hydrology” by reliability
  • Separate soils from “Other Indicators of Hydrology” (i.e., soils provide the best evidence for the presence (or absence) of long-term wetland hydrology for the purposes of wetland boundary delineation. Furthermore, soils are separate in the federal method).
  • Inclusion of both a simplified list and a detail list of hydric soil indicators
  • New data form. (i.e., the new data form reflects the changes in the rest of the Handbook and aligns to the extent possible with the federal delineation data sheet).

While MassDEP recognizes that the Manual will be used by wetland science practitioners, the primary audience is the municipal Conservation Commissions. Therefore, it was determined that the Manual should present the information using understandable language that avoids technical jargon; yet still provide references to specific technical information required for other wetland science practitioners or interested Conservation Commissioners.