Wetland Monitoring & Assessment Demonstration Project: Assessment of Wetland Mitigation Success

Transcription

1 Wetland Monitoring & Assessment Demonstration Project: Assessment of Wetland Mitigation Success Lisa Rhodes, MassDEP Wetlands Program & Scott Jackson, UMass Amherst ASWM Webinar April 29, 2015

2 Massachusetts Wetland Protection Regulations: Impacts limited to 5000 sq ft (with some exceptions) Permitting process handled by local volunteer Conservation Commissions and overseen by the MassDEP Wetlands Program Wetland losses must be replaced in accordance with the following conditions Surface shall be equal to lost area Groundwater and surface elevation shall be equal to lost area Horizontal configuration with respect to bank similar to lost area Unrestricted hydraulic connection to same waterway or body as lost area Same general area or reach of waterway or body as lost area 75% surface shall be reestablished with indigenous wetland plant species within two growing seasons

3 Wetland Monitoring & Assessment Demonstration Project: Assessment of Wetland Mitigation Success Study funded by EPA 2011 Wetland Program Development Grant Follow up to Compensatory Wetland Mitigation in Massachusetts by Stephen Brown and Peter Veneman - December 1998 BACKGROUND water/resources/a-thru-m/cwm.pdf

4 2015 Mitigation Study Notes: 1. Wetland Replacement areas studied are those that are: created from current upland/historic upland created from current upland/historic wetland. 2. TERM: Replacement Area: Area built, whether or not it is determined to be a wetland 3. TERM: Wetland created: area with > 50% hydrophytes and hydric soils and/or other indicators of wetland hydrology

5 2015 Study: 44 Towns Studied Random selection Representation by DEP Region, Ecoregion, population, number of NOI s 4 towns added to ensure representativeness

6 Approx applications reviewed, 176 required wetland replacement that met study criteria 46 projects proposed never went forward, 39 either unclear or no permission to access; Rec d permission to assess 91; 12 had project built but replacement area not built Field Assessments (79) Research and Field Assessment Transects (100 points total) for 75% cover Visual % cover estimate of plants > 1% Soil pit to ID hydric characteristics Other indicators of wetland hydrology Size of Replacement Area measured Reference sites: same assessment

7 Reference Sites Assessed wetland adjacent to the lost wetland or adjacent to the replacement area (most) In many cases, lost wetland fragmented (more than one lost wetland area), or adjacent remnant affected by construction (i.e. Phragmites) or not accessible About half projects had no information on lost wetland type Reference wetland boundary was wetland delineation approved by Conservation Commission

8 Public Road/Private Way Rapid Assessments (if visible) Was replacement area built? Was wetland built? what plants? Landowner Access Major Task Concern: Data Bias (no permission = non-compliance?) Developed a Correction Factor to get more realistic compliance rate

9 Wetland Mitigation Success Preliminary data Do not cite

10 Key Problem: Hydric Soils and Hydrology 28/79 sites assessed: wetland not created 28/28 sites where wetland not created: no hydric soils and/or other indicators of wetland hydrology 25/28 sites where wetland not created: wetland plant criteria >75% met

11 Size of Replacement Areas n = 75 Included as appropriately sized are wetland replacement areas 90% of size required by permit. Preliminary data Do not cite

12 Regulatory Compliance Criteria for Regulatory Compliance Wetland vegetation ( 75% cover) Hydric soils or other indicators of wetland hydrology Appropriately sized Groundwater and surface elevation shall be equal to lost area Horizontal configuration with respect to bank similar to lost area Unrestricted hydraulic connection to same waterway or body as lost area Same general area or reach of waterway or body as lost area Preliminary data Do not cite

13 Certificates of Compliance 16.7 % of replication areas that were never built (2 of 12) received CoCs 32.1 % of replication areas that failed to produce wetlands (9 of 28) received CoCs 31.2 % of replication areas that failed to meet all regulatory requirements (15 of 48) received CoCs Preliminary data Do not cite

14 Success: Permitted by Conservation Commission vs. MassDEP Success built Success wetland Success wetland + size Success wetland + compliance Conservation Commission 85.5 % 69.5 % 49.2 % 45.8 % MassDEP* 87.5 % 42.9 % 28.6 % 14.3 % Overall 86.8 % 64.6 % 45.6 % 39.2 % * Sample size was very low; n = 8 Preliminary data Do not cite

15 What factors are correlated with mitigation success? Predictor Variables Tested Population # of filings Date permitted Replacement area size Wetland type Limited project status Quality of application Quality of permit Quality of permitting process Quality of monitoring No significant relationships found

16 Vegetation Similarity Replacement vs. Reference Site Preliminary data Do not cite

17 Significant relationship between vegetation similarity and wetland type (p<0.01) Preliminary data Do not cite

18 Vegetation Wetness Index Replacement vs. Reference Site Significant relationship between deviation in vegetation wetness index and wetland type (p<0.001) Preliminary data Do not cite

19 Are Wetland Seed Mixes and Nursery Stock Distorting the Picture When it Comes to Mitigation Success? Vegetation wetness index indicates that replacement areas are vegetatively wetter than reference sites Particularly for the driest wetland type (forested wetland) Evaluation of soils and other indicators of hydrology suggest that many replacement areas are actually drier than the reference sites 28 or 79 replacement sites failed to create wetlands 25 of these sites met the wetland plant criterion ( 75% cover)

20 Some good wetland replacement areas were built

21 Natural Wetland Where does the natural wetland end and the replacement area begin? Replacement Wetland

22 Which is natural and which is the replacement?

23 Which is natural and which is the replacement? Replacement

24 Variance Replacement Area after 16 years

25 Lots of Poor Examples as Well

26 Key Problem: Lack of Hydric Soils and/or Indicators of Wetland Hydrology Most sites where wetland not created: Met wetland plant criteria Did NOT meet criteria for hydric soils and/or indicators of wetland hydrology

27 Wetland Boundaries Too Aggressive Replacement area up here

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29 Many sites had invasive species which can be difficult to remove if not caught early

30 Erosion Controls not maintained and/or left in place

31 Planted species should be native not ornamental varieties.

32 If the proposed replacement area is spray-painted, does that mean it s under construction?

33 Overall Statewide No Net Loss Sites Wetland Created (acres) Wetland Created meeting Performance Standards (acres) 50 sites Outlier Site Variance Sites (above 1:1) TOTAL acres required by OOC (91 sites): 7.24 TOTAL acres impact proposed (91 sites): 5.26

34 Avoidance, Minimization Average Acres of Wetland Loss per Year by Flyover Year Flyover Year 34 21

35 Interim Solution: Guidance and/or Regulation Revision to improve in-kind replacement Possible Targets: Size criteria (increased ratio?) Increased flexibility in location Consider financial assurance mechanism to guarantee mitigation success Greater construction oversight

36 Interim Solution: Consider New Performance Standard for Demonstration of Hydric Soils/Hydrology Evidence of saturation or inundation (typically seasonal average groundwater for sufficient duration and/or hydric soil formation within designated upper depth) prior to COC Require design, construction & post-construction information on site hydrology (e.g. soil test pits, GW monitoring)

37 Long Term Solution: Technical Advisory Committee Options for Deliberation GOAL: Increase success, no net loss, reduce # replacement areas Reduce 5000 s.f. based on average alteration (10.55(4)(b)) Hybrid In-lieu fee: Develop Threshold (Below = lieu fee allowed; Above = replacement required (ratio TBD); flood storage/pollution prevention for all projects on site) Banking Alternatives Require Environmental Monitor, specify credentials Require buffer zone around wetland replacement areas

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