Here is a Google video of most of the Conservation Commission meeting of February 26. Only a short portion at the end was not recorded. This video is 3 hours and 12 minutes long and was recorded by Adam Cohen. It is also available on Vimeo.
Here are the agenda items covered in the video:
5:30 PM (0:00:00-0:02:14 on video)
Continuation of a Notice of Intent filed by Smith College for the
relocation of a tennis court, creation of a synthetic playing field,
and the paving of an existing gravel parking lot. Work is proposed to
take place in Riverfront Area. Project location is College Lane at
Smith College, Map Id 31C-15.
A discussion of plantings at the Ruggles live-work space followed the Smith College item.
5:45 PM (0:20:00-0:29:14 on video)
Notice of Intent filed by Nitsch Engineering on behalf of the
Massachusetts State Police for the installation of bollards, lights and
conduit along the perimeter of existing paved areas. Work is proposed
to take place in Riverfront Area and the 100-foot Buffer Zone to
Bordering Vegetated Wetlands. Project location is 555 North King
Street, Map ID 13-045.
6:00 PM (0:32:15-3:11:55 on video)
Continuation of a Notice of Intent filed by Tofino Associates, Inc. and
Northern Avenue Homes, Inc. for the construction of twenty-five
dwelling units and associated roadways, parking areas, driveways,
sidewalks, utilities, landscaping and stormwater management system.
Project is proposed to take place in the 100-foot buffer zone of
Bordering Vegetated Wetlands. Project location is Northern Avenue, Map
Id 25C-12 and 25C-17.
At their previous hearing on January 22, commissioners expressed concern
about the large number of people Kohl Construction proposed to house close to
a wetland off North Street. They feared steady encroachment towards the
wetland over time. Although Kohl reduced units by only two (from 25 to
23) in its latest proposal (shown below), the commissioners appeared to
be largely satisfied with the new layout. At the
February hearing they generally contented themselves with
second-order questions, with the important exception that they and the
Department of Public Works have yet to review and approve Kohl’s new
stormwater mitigation proposal.
During the hearing, some expressed the opinion that wetlands in outlying areas are
more valuable that those in more urban areas, and deserve more
protection from development. We agree this is generally true from the
standpoint of wildlife habitat, but disagree when it comes to flood mitigation, pollution control, and physical and psychological benefits to people. Indeed, some locales in the US require larger buffer zones around wetlands in areas of more intense development.
Smart Growth proponents want to reduce car travel through urban infill. That’s a worthy goal, but it’s being given too much weight in this instance. A broader perspective is needed, one that acknowledges the value of urban greenspace as well as the susceptibility of Northampton to flooding.
the hearing, Conservation and Land Use Planner Bruce Young maintained
that Northampton’s new Wetlands Ordinance expresses a clear public
consensus that encroachment to within 35 feet of wetlands in our zoning
district (URB) is generally acceptable. We are not convinced this consensus is solid. In a key presentation to City Council
in 2007, Young suggested the new Wetlands Ordinance would be used to
facilitate modest encroachments like accessory apartments. This is a
far cry from Kohl’s proposed 23 units, roads and parking spaces.
Moreover, in a 2006 survey conducted for Sustainable Northampton, 90% agreed that “We Should Protect More Open Space & Wildlife Corridors”. In 2007, over 2,000 Northampton residents signed NSNA’s petition
which called on the city to protect significant trees and “revise
Northampton’s wetlands protection ordinance to emphasize that new
development should not occur within 100 feet of a wetland in any part of the city unless exceptional circumstances apply”.
And finally, encroachment inside of 50 feet is on shaky ground scientifically. These buffers are generally too narrow to provide effective protection to wetlands.
public is urged to attend Kohl’s next hearing before the commission,
scheduled for Thursday, March 12 at 6:15pm, City Hall Hearing Room, 2nd
Here is the portion of the most recent staff report prepared by Bruce Young that comments on the Tofino/Northern Avenue Homes/Kohl Construction proposal:
The project can be permitted but, the Commission should continue the hearing until the applicant provides updated stormwater calculations that are acceptable by the Commission and the Department of Public Works.
Assuming that the Planning Board may modify the plan, a condition could be added that allows minor modifications to the site plan in the area between the 35’ No-Disturb area and the 100’ buffer zone, as long there is no net increase in the total amount of impervious surface within that area.
Other possible conditions:
- General Conditions #1-32
- Barrier along Limit of Disturbance Line
- Covenant-snow shall not be stored in wetlands, buffer zones or stormwater control areas
- Barrier along areas where wetlands or stormwater controls are adjacent to streets or sidewalks
- Covenant-Road salt or lawn chemicals shall not be used on any property. An annual signoff of this requirement by the homeowners association shall be provided to the Conservation Commission by October 1st
- Covenant-Annual inspection report of the No-Disturb Area shall be submitted to the Conservation Commission by October 1st
- Applicant provides a five-year invasive removal plan for entire site. Funding or a covenant requiring funding by the Homeowners Association shall be required to implement the plan. Annual reports on the invasive removal project shall be submitted to the Conservation Commission by October 1st
- Applicant replaces the proposed rip-rap outlet structures with a material that provides enhanced habitat value
- All sidewalks and bikepaths shall be constructed of pervious pavers or pervious pavement
- Above ground cisterns and rainbarrels could be used to catch and store some of the roof runoff.
- Street sweeping should be conducted two to four times per year.
At the February 26 hearing, Jono Neiger of Regenerative Design Group noted that removing large numbers of mature trees, as Kohl proposes to do, may cause the already high water table to rise even further. One commissioner appeared to believe this might be a good thing, with more water flowing into the wetland. The implications for the condo owners, however, are less positive, with an increased risk of flooding and other water-related problems. Below is an edited version of Neiger’s presentation sheet. Neiger serves on the faculty of the Conway School of Landscape Design, Graduate Program in Sustainable Landscape Planning & Design.
Potential effects of Norway Spruce (Picea abies) removal on water table level for the North St. Neighborhood Association
The removal of the Spruce could have a significant effect on the water table. It is estimated that the wooded area to be cleared pumps out 410,000 gallons of water a year out of the water table. This is equal to 1.25 feet of water per year which could translate to a water table elevation of 2.5-3.4 ft depending on soil porosity and hydrological dynamics.
Calculations are based upon 380 mm (1.25 feet) per year transpiration (Cienciala, Lindroth, Cermak, Haellgren, & Kucera, 1994) and the removal of 41,000 square feet of wooded area.
It would be assumed that being evergreens the spruce trees would use more water in the winter time than deciduous trees but Kozlowski found no significant difference in transpiration rates (Kozlowski, 1943).
Some studies show that willow and poplar species have a transpiration rate 2-4 times that of spruce trees therefore replanting half to a quarter of this area in willow or poplar could provide the same benefit.
Cienciala, E., Lindroth, A., Cermak, J., Haellgren, J. E., & Kucera, J. (1994). The effects of water availability on transpiration, water potential and growth of Picea abies during a growing season. Journal of Hydrology (Amsterdam), 155(1), 57-71.
Kozlowski, T. T. (1943). TRANSPIRATION RATES OF SOME FOREST TREE SPECIES DURING THE DORMANT SEASON. Plant Physiology, 18(2), 252-60.
More Information on Biodrainage
A. F. Heuperman et al., Biodrainage: Principles, experiences and applications (FAO, 2002).
“CHAPTER 3. WHAT IS BIODRAINAGE, HOW DOES IT WORK? – ISSUES RELATED TO ITS IMPLEMENTATION”, http://www.fao.org/DOCREP/005/Y3796E/y3796e07.htm#TopOfPage
Basic Information on Transpiration
“The Water Cycle: Transpiration, from USGS Water Science for Schools”, http://ga.water.usgs.gov/edu/watercycletranspiration.html
Neiger exhibited this chart which makes clear the amount of impervious surface Kohl proposes to add to this currently green area. The yellow line denotes the 100-foot buffer zone around the Millyard Brook wetland. The impact of the project extends beyond the impervious surface, as construction work and the stormwater systems would necessitate the removal of many additional mature trees up to the 35-foot buffer line.
Here are images of the current proposal as presented by Kohl on February 26 (see also the schematic diagrams released earlier):
Kirby on the Loose: “Boulders or barbed wire? The Kohl development” (2/28/09)
…The really cogent issue about this development remains how it will handle storm water runoff and affect the forested wetlands behind it. OK, the project plan is better today, but the land they are building on is very wet. No cellars in this development, and the dry-wells to handle runoff off the roofs only are 12 inches deep. Low Kirby confidence in these dry wells handling big storms without overflowing.
Commission member Paul Wetzel, who I am growing very fond of, broached the critical question gently to the developer. You have to lean forward to hear him when he talks. He’s kinda shy, he hesitates, he’s a wetland technician and not an orator. He is, however, pointing at the right place on the map, at the outlet of the detention pond, and asking the right question. With the plans laid out in front of him, he wonders if these are the right elevation figures. “88.8 feet?” he says, “I was hoping” he said, shaking his head, “It would be a little higher?”
It’s not easy cutting through the heavy layer of fog, mystification and legend that goes with designing and promoting projects. You have, of course, the experts bought and paid for by the developer. All the guys with suits. Most of the time they will tell you things are ok. There are maps, there are studies, there are mysterious tables, but very seldom is there any effort at making things comprehensible to the layman. There is, however, a useful law that says that the bottom of the detention pond must be two feet higher than the seasonal high water.
To see a project where this was ignored, go over and take a look at Carlon Drive. The detention pond there is full of water year around, and is today a frozen lake. Detention ponds are supposed to hold water for awhile, and then gradually discharge it after the storm passes. The outlet structure that Kohl’s people have designed is a sophisticated affair with three outlets of differing cross-section. The basin is supposed to be dry except during storms. But will it empty in the spring when the nearby creek is overflowing? Will it be a stagnant pond in early summer? The Jury is out.
This outlet structure won’t work if it is underwater. The closest test well I found to the detention basin was well #4, where the seasonal water table was between 88 and 89 feet. This means that you’ll probably have a wet floor in the detention pond. And these readings are predevelopment, before you cut down all the Norway Spruce that shelter and help dry out this area, and before you build all the structures and parking lots, which will raise the water levels. So what is needed before the bulldozers begin, is a couple more test wells inside the redesigned detention pond. Then one document that shows a cross-sectional analysis of the project from the buildings to the swamp showing elevations and groundwater levels, pre and post development. Then we might see what is going on and what will happen to the water coming off the roofs and parking lots. Too bad you can’t stress test a development in the planning stage like they are planning to do with the big banks. See what happens with those drywells and detention structures when a 50 or 100 year storm hits. I know the experts that developers hire are supposed to tell us that, but I tend not to believe their computerized models. There are always these hidden adjustments that can be made.
…Most of the land in the low areas surrounding downtown today that is undeveloped should probably remain undeveloped. It is just much too expensive for developers to develop responsibly, and these swampy areas provides an essential margin of safety against flooding.
[NSNA comment: Kohl’s stormwater engineer disputes that the two-foot rule applies to the kind of detention basin they’re using. However, our concern remains that water will stagnate in this basin and cause problems (e.g. mosquitoes, unsightly algae, flooding in the condo units nearby).]
Mosquito Control Practices Near Wetlands: Methods, Risks and Limits
Constructed (artificial) wetlands, built to manage and treat urban
storm and/or wastewater, come in various formats; they may start out as
simple vegetated pools but can develop into dense swamps. They have the
potential to be more productive of mosquitoes than their natural
counterparts, and must be carefully assessed for mosquito productivity
Shallow vegetated water typically supports more mosquito
breeding; deep pools with steep and deep edges, and no emergent or
surface vegetation, provide less suitable habitat for mosquitoes.
Any wetland area, constructed as a shallow vegetated pond, will be a major concern for mosquito breeding…
“Innovative Non-Zoning Approaches to Encourage Smart Growth and Protect Public Health” – Video with Wayne Feiden and Bruce Young
1:03:00… Young: “We have some serious challenges ahead of us.
And one is… ‘HIGs’, holes in the ground. And so, what we’re saying
is, we want good infill development, but through our Wetlands Ordinance
we didn’t really adopt stormwater standards that would improve the
stormwater in these infill areas. So we have a challenge to come up
with better design standards for stormwater instead of these giant
holes in the ground, and to actually require or implement some, or
incentivize some low-impact development type of stormwater systems. And
then…the second thing that goes with stormwater systems is
maintenance… We’re working with the Department of Public Works that
now has a stormwater manager and we’re setting up maintenance for these
systems, but some of these are older systems and some of these have
been approved under a system that didn’t have basically [what’s modern]
for these types of systems…
“And then finally, Wayne and I
mentioned this earlier, design standards in architectural ordinances.
We really need to think about how the infill happens. Because if we’re
saying we want a house between two houses, and we can’t get the
neighborhood to buy onto houses that are just not helping the
At 1:13:30 during the Q&A session, Cohen asked Feiden and
Young about the Meadowbrook Apartments. The experience of this
development raises concerns about the hazards of building homes near
wetlands. As former City Councilor Mike Kirby wrote in June:
The developers built 255 units of affordable
apartments there. They crammed them in everywhere they could, pushing
them up into the bluffs, and close to the creek and wetlands. No
backyards to speak of. One third of the buildings were built within 50
feet of the wetlands, 63% of the buildings are within the customary 100
feet of wetlands.
None of the buildings have cellars under their
apartments. If they have cellars, there are people living in them. The
cellar floors in the basement apartments in Buildings #4 and #2 are
lower than the surrounding swamp. Some slabs have cracks in them.
People have been flooded out. No moisture-proof barriers between the
surrounding earth and the foundations. Moisture and mold percolate up
into people’s apartments via the chases that hold utilities. If you
wonder why low-income children are afflicted with a whole host of
respiratory diseases, you have to look no further than the children of
the floor level and basement apartments of Meadowbrook…
Feiden and Young were apparently unfamiliar with the problems at Meadowbrook…