April 1, 2021 ~ Conservation Commission Meeting

2021-04-01 · Conservation Commission · 1:40:16 · watch on YouTube →

A working session, the second of two, in which George, the town planner, walked the Conservation Commission through his research on realigning Durham's resource protection zoning as the 2018 comprehensive plan recommends. He showed that the town's current resource protection zoning is far broader than state law requires and rests on pre-2002 floodplain maps and swamps drawn on the tax maps, and set out nine draft criteria for a refined map, pausing on each for discussion. The commission agreed to keep the no-development rule in the 100-year floodplain while updating to current FEMA mapping, but set aside the stream buffer question and the forested wetland question for further work, wanting to look at Beginning with Habitat data and to find GIS help before deciding. George also laid out the legal and political constraints, including investment-backed expectations and the cost of doing the wetland analysis properly. Nothing was binding; the commission agreed to digest the material, come back on April 22 to discuss among themselves, and then act as advocates for whatever direction it settles on before the work returns to the planning board.

No written minutes could be matched to this meeting. The transcript records that the speaker changed but never who was speaking, so any name attached to a statement below is inferred from context and is marked (?).

What was discussed

1. 0:01
   Opening and purpose

   The meeting was recorded and Kathy started the stream. George, the town planner, introduced his research on implementing the 2018 comprehensive plan adopted by voters at town meeting, and offered a recap for Jess and Kit, who had not been at the previous week's workshop. He described the session as education as much as policy development, and said he had taken this time because the planning board was tied up with other issues.

2. 0:01
   The four framing questions

   The presentation was built around four questions carried over from the last session: how Durham's resource protection compares with state requirements, how the current zoning came to be, what the current comprehensive plan says about it, and what a refinement of the resource protection zoning would look like.

3. 0:01
   How Durham compares with state law

   Under the mandatory shoreland zoning act, only the floodplain and steep slopes along the Androscoggin River, the wetlands and forested wetlands surrounding Runaround Pond, and the borders of some of the roughly six large emergent wetlands identified in town must be resource protection. Comparing that with the November 3, 2020 zoning map, George showed that Durham's resource protection zoning, which precludes most if not all development, is far more restrictive than the state requires.

4. 5:24
   How the current zoning came about

   The primary impetus was the 2002 comprehensive plan, adopted during the growth boom of the early 2000s when towns across southern Maine were adopting growth caps. It set three criteria: floodplains along the river, Runaround Pond and all stream systems; wetlands of 10 acres or more, including forested wetlands as well as the emergent wetlands the state focuses on; and all shoreland areas, which the town chose to zone entirely as resource protection.

5. 5:24
   Where the tree height definition comes from

   A member questioned the 18-foot tree height used to define forested wetland, noting it does not match the Army Corps standard of three inches diameter at breast height regardless of height. George (?) said the figure, which is six metres, comes from the DEP regulations rather than the Army Corps.

6. 5:24
   What the 2018 comprehensive plan recommends

   The plan came out of a public participation process between 2016 and 2018 and calls for refining Durham's regulations to reflect updated natural resource data and to be more consistent with state law. Overlaying the current FEMA floodplain mapping on the pre-2002 mapping shows the floodplain shrinking dramatically to narrow corridors along the watercourses, and the older, larger floodplain is the biggest single basis for the town's existing resource protection zoning.

7. 5:24
   Updated wetland inventory and Beginning with Habitat

   The comprehensive plan also references a more recent National Wetlands Inventory map of forested and non-forested wetlands of 10 acres or more, and the Beginning with Habitat analyses. The plan's strategy is to identify areas with a co-occurrence value of six or more natural resource values and consider resource protection zoning or mandatory clustering to preserve them.

8. 10:45
   Why floodplains change

   Asked how much floodplains move, George (?) said that in Durham the change has been driven by more accurate analysis and mapping rather than channel migration, and that sea rise affects coastal zones rather than these watersheds. He said the single change that would most reduce the mapped floodplain would be removal of the dam at Lisbon, which backs water up the river.

9. 10:45
   The aquifer protection precedent

   George used the aquifer protection district as the model. More accurate sand and gravel aquifer mapping done by the state in 2011 showed the district was not aligned with the actual aquifers, so in the last round of land use ordinance and zoning map updates the map was revised, taking some areas out and putting others in. He described the resource protection work as the same kind of realignment, and showed an early draft comparison map produced by the Greater Portland Council of Governments.

10. 10:45
    The nine draft criteria

    The draft criteria are the 100-year floodplain on current FEMA maps; all areas subject to mandatory shoreland zoning; land within 75 feet of a perennial stream; land within forested wetlands of 10 acres or more together with contiguous wetlands; land within emergent wetlands of 10 acres or more; land within 75 feet of such emergent wetlands unless rated moderate or high value for waterfowl and wading bird habitat; land rated by Beginning with Habitat at six or more co-occurring values; and, added at the commission's request, those six-plus areas that are not currently zoned resource protection.

11. 16:37
    Criterion one: the 100-year floodplain

    Since 2002 the town has allowed no development in the floodplain, while many communities allow it subject to federal flood mitigation standards such as breakaway walls. George (?) noted the town has a flood management ordinance but that it applies to very few properties, perhaps a dozen at most with buildings on them, the rest being undeveloped, and said he assumed no development remains the better policy since flood-proofing is designed only to a 100-year level.

12. 16:37
    Flooding on Route 136

    Members recalled that flooding used to shut Route 136 down, cutting children off from getting across, and that traffic diverted over Bowie Hill and Stackpole. It was noted this has not happened since the embankments were built and the road was moved, but that a large enough flood would do it again.

13. 21:52
    Climate change and mapping to a moving target

    Jess (?) raised whether modelling exists for the effect of climate change on floodplain extent given more frequent severe storms, and a member asked whether the rule should be tied to a fixed map rather than one that keeps changing. George's answer was that the practice is to revisit the zoning map whenever FEMA updates its mapping and take the revision to town meeting.

14. 21:52
    Legal principles: science and investment-backed expectations

    George set out two principles he asked members to keep in mind. Regulations need good data, a rationale and a public process behind them. And under the doctrine of investment-backed expectations, someone who bought land that has long been resource protection has a weak case against the town, whereas a new restriction that removes property rights without sound policy behind it gives an owner far more leverage. He noted this is also why shoreland zoning rules carry so many exemptions for pre-existing development.

15. 27:04
    What a 100-year flood actually means

    A member asked for a definition. George (?) explained it is a 1% probability in any given year rather than an event that happens once a century, so back-to-back 100-year floods are possible, and members observed that climate change raises that frequency and that the term is misleading.

16. 32:44
    Criterion two: mandatory shoreland zoning areas

    The current policy zones all of it resource protection. The alternative would be to adopt the state's own shoreland zoning categories, which allow limited residential around large open wetlands, or limited commercial to accommodate home-based businesses, or stream protection. A member observed the area largely overlaps the floodplain and so is protected anyway, and George (?) said there seemed no compelling reason to change direction.

17. 32:44
    Criterion three: stream buffers

    George walked the board around the town's named brooks, which drain eventually to the Royal River or the Androscoggin, and set out three separate policy variables: the width of the buffer, the type of buffer, and which class of streams it applies to. DEP has standardised on 75 feet across its programmes; Durham has had 100 feet since at least 2004; conservation groups argue for wider buffers as wildlife corridors.

18. 32:44
    Buffer type and which streams

    The strictest option is the current resource protection within 100 feet, administered by the code officer. Less strict is stream protection under shoreland zoning, also locally administered. Least restrictive is relying on the Natural Resources Protection Act rules, administered by DEP rather than the town. On coverage, most stream segments in Durham are not required to be shoreland zoned; the requirement generally starts where two perennial streams meet.

19. 38:01
    The conflict between 100 and 75 feet

    Asked what problems the 100-foot rule has caused, George (?) said people read the DEP regulations, see 75 feet, and build accordingly; at least once since he began working with the town a foundation went in at about 84 feet from a stream, after which the owner went to DEP, DEP thought the town had it wrong, and the two ended up at odds. His view was that consistency with state law serves everyone better unless the town can make a compelling case from scientific data for a wider buffer.

20. 38:01
    Looking at habitat data before setting a buffer

    Roberta (?) suggested starting from the Beginning with Habitat maps to see whether priority habitat along streams such as Newell Brook extends beyond 75 feet, and whether widening a buffer in places would connect priority areas as a wildlife corridor. Juliet and another member agreed some riparian zones are likely already captured as six-plus co-occurrence areas, and the question was set aside for a later meeting.

21. 43:34
    Criterion four: forested wetlands and contiguous wetlands

    George showed how the National Wetlands Inventory classifies each wetland by class, subclass and hydrology, and why a straight 10-acre GIS cut is misleading: a mapped 20-acre forested wetland can sit directly against a 9.39-acre wetland of slightly different classification that never appears, and a single system split by drainage channels can be seven separate sub-10-acre entries. Adding the phrase "along with all contiguous wetlands" is intended to capture the whole system.

22. 48:51
    What the current map is actually based on

    George (?) said that in 2002 there was no GIS mapping, so the town defined its 10-acre-plus wetlands by whether a swamp appeared on the property tax maps, with no field or GIS analysis. Those tax maps remain the basis of the current resource protection zoning, and wetlands he had just shown at over 20 acres do not register on them.

23. 48:51
    How contiguous wetland language would work in practice

    A member asked what happens when an owner developing a property finds their drainage connects to a 10-acre forested wetland off site, given the inventory maps are coarse. George (?) said the zoning map does not respect property lines, so one owner can be restricted where a neighbour is not, and that whether unmapped contiguous wetland is caught would be a legal question, with lawyers arguing both that an unmapped area does not count and that the map is only a general representation to be tested by field analysis.

24. 54:13
    Three options for forested wetlands

    The options are to zone only what the National Wetlands Inventory maps as 10 acres or more; to add all contiguous wetlands, which George called defensible both politically and legally; or to stop zoning wetlands as resource protection at all and rely on the Army Corps and DEP. Under those rules an owner may alter about 4,300 square feet without permitting, faces alternatives analysis and mitigation up to an acre, and compensation beyond that. George (?) said Durham is unlikely to choose the third but wanted it on the table.

25. 59:17
    What doing it properly would cost

    George estimated a detailed study of all the town's wetlands, identifying and analysing each system on the inventory, at around $20,000 to $30,000, and said the planning budget is bare bones and public funding for such studies is scarce. He also noted nothing can change until the next town meeting a year away, that he is teaching himself the free QGIS software, and that he has exhausted GPCOG's mapping help and been referred back to them by Beginning with Habitat.

26. 59:17
    Finding GIS help

    A member argued the analysis is not as hard as it sounds: a GIS consultant would cut the National Wetlands Inventory layer for Durham, filter to 10 acres and above, add anything adjacent and produce a layer. Members thought the cost would be modest and that pro bono help might be available, one recalling someone who had offered back when Paul was here.

27. 1:09:52
    The political risk

    George cautioned that once the analysis reaches individual wetlands, zoning the land around existing homes as resource protection will draw political fire, and that owners will ask why the town is doing it when the Army Corps already regulates the wetland. Members acknowledged the science has to be balanced against that.

28. 1:09:52
    Criterion five: emergent wetlands

    Asked what emergent means, George (?) explained both emergent and forested areas are wetlands by soils, hydrology and vegetation, the difference being whether the preponderance of trees reaches 18 feet. He said he had struck the contiguous wetlands phrase for emergent wetlands because of the inevitable relationship with the wetlands surrounding them, and described how Mike Morris's reviews for the town had flagged which emergent wetlands had to be brought under shoreland zoning.

29. 1:15:17
    The 250-foot buffer around emergent wetlands

    An emergent wetland of 10 acres or more must be surrounded by a 250-foot shoreland zone, which must be resource protection where the adjoining land is forested wetland and can be limited residential otherwise. When the town did this, one property owner hired a wetland consultant who contacted George to confirm the zoning would not stop him building houses along the road in his open fields, which it did not.

30. 1:21:13
    The option to reduce 250 feet to 75

    State law lets a municipality limit the shoreland zone around a freshwater wetland to 75 feet rather than 250 where the wetland has not been rated by Inland Fisheries and Wildlife as moderate or high value for waterfowl and wading bird habitat, provided the town applies the stream requirements. Inland Fisheries and Wildlife has identified five such wetland systems in Durham, and George (?) noted the 250-foot buffer around agricultural fields drew a significant landowner backlash when those wetlands were brought under shoreland zoning.

31. 1:21:13
    Why this may be less contentious than it looks

    Four of the five moderate to high value wetland systems are already zoned resource protection, so applying the 250-foot requirement to them changes little. On the fifth, George found the northern part was 8.76 acres and the adjacent emergent wetland 6.54 acres at the time of the inventory, both under 10 acres, so DEP would not require shoreland zoning there at all.

32. 1:26:25
    Options for emergent wetlands

    The choices are to keep 250 feet around all emergent wetlands, or to keep 250 feet around the moderate and high value habitat systems and reduce the rest to 75 feet under the state provision. The current policy applies DEP standards with a 250-foot buffer of resource protection or limited residential.

33. 1:26:25
    Criteria eight and nine: Beginning with Habitat

    George showed the overlay of areas rated at six or more co-occurring natural resource values against the proposed revised resource protection map. The correspondence is close, with most of the darker green falling along stream corridors that would already be captured as floodplain or wetland, and the ninth criterion added at the commission's request covers six-plus areas not currently zoned resource protection.

34. 1:31:51
    The circle on the habitat map

    A large circle on the Beginning with Habitat map was identified as a rare species occurrence, mapped as a broad radius so the exact location is not disclosed and collectors cannot find it. Members thought it was Blanding's turtle associated with Runaround Pond, and noted most of the circle is already wetland, pond or stream buffer, with the developed land and open agricultural fields inside it unlikely to be good habitat.

35. 1:31:51
    Mandatory clustering as an alternative

    The comprehensive plan offers resource protection or mandatory clustering for six-plus areas. Under clustering an owner could still get the same number of two-acre lots but would have to group the development and preserve open space, with a wildlife biologist analysing reptile migration routes so they fall within the common open space. George cited a Falmouth subdivision required to build an amphibian crossing under the road when vernal pool rules came in.

36. 1:31:51
    Next steps and the balance to be struck

    The plan is for the commission to discuss the recommendations at its next meeting and decide what to change, after which the work goes back to the planning board for consideration of amendments, with a joint meeting of the two bodies that Juliet has been pushing for. George (?) warned the planning board will bring the perspective of landowners and developers, and that unless residents feel the process is fair, equitable and based on good data, political opposition to environmental regulation becomes intense.

37. 1:37:16
    Town email transition

    Members discussed the changeover of town email accounts, with some accounts already working, one member unsure whether older messages would be lost, and two members needing Durham addresses set up.

38. 1:37:16
    Next meeting

    The next meeting falls on April 22, the fourth Thursday, at 6:30. Members chose to use it to digest and discuss among themselves rather than have George return, having agreed they could email him questions in the meantime, and noted the need for a consistent strategy to work through all the areas involved.

What was decided

• 27:04
  Keep the town's existing policy of allowing no development within the 100-year floodplain, and refine the map to the most recent FEMA mapping, revisiting the zoning map at town meeting whenever FEMA updates its maps. Agreed by consensus when the chair asked whether everybody was on board.passed
• 32:44
  On areas subject to mandatory shoreland zoning, members leaned toward keeping all of it as resource protection rather than adopting the state's limited residential, limited commercial or stream protection categories, on the basis that much of it overlaps the floodplain anyway. No decision was taken and the recording does not record a vote.outcome unclear
• 38:01
  Set aside the stream buffer question, covering whether to keep the town's 100-foot buffer or move to the state's 75 feet, what type of protection applies, and which streams it applies to, until members have looked at the Beginning with Habitat maps to see whether priority habitat and wildlife corridors justify a wider buffer in places.tabled
• 59:17
  Set aside the forested wetland criterion, with members to look for a GIS consultant, possibly working pro bono, who could cut the National Wetlands Inventory layer for Durham, filter to wetlands of 10 acres and more and add contiguous wetlands, so the commission can see what is actually there before deciding among the three policy options.tabled
• 1:31:51
  The commission will act as advocates for whatever policy direction it settles on, with the work then going back to the planning board for consideration of amendments and a joint meeting of the planning board and conservation commission to follow.passed
• 1:37:16
  Use the next meeting, April 22 at 6:30, for members to digest and discuss the material among themselves rather than asking George to attend again, with members free to email him questions before then. George will send the slides out as a PDF.passed

An outcome reads "unclear" where the recording does not state it plainly. The recogniser drops short words, and "the motion does not carry" is one missing word from its opposite.

Worth knowing

• 0:01
  Durham's resource protection zoning is far broader than state law requires. Under the mandatory shoreland zoning act only the Androscoggin floodplain and steep slopes, the wetlands around Runaround Pond and the borders of some of the roughly six large emergent wetlands in town must be resource protection; the rest is the town's own choice.
• 48:51
  The current resource protection map rests on weak data. In 2002 the town had no GIS, so it defined its 10-acre-plus wetlands by whether a swamp appeared on the property tax maps, with no field analysis, and used floodplain mapping that FEMA has since revised down substantially.
• 38:01
  Durham requires a 100-foot buffer along streams while DEP has standardised on 75 feet, and the mismatch has caused real problems. At least once, an owner built a foundation about 84 feet from a stream relying on the state figure, then found the town's rule was stricter, leaving the town and the state agency at odds.
• 59:17
  A proper study identifying and analysing all the town's wetlands was estimated at $20,000 to $30,000, against a planning budget the planner described as bare bones. Nothing can be changed in any case until the next town meeting, roughly a year away.

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