June 4, 2025, Planning Board Regular Meeting Transcript - WEHI

19 of 41 sheets Page 73 to 76 of 101 06/20/2025 06:55:03 AM 73 THE WITNESS: I don't know for sure.1 THE PUBLIC: Okay.2 THE WITNESS: But one of the things I can3 describe is you look at development patterns, something4 like this. So this is a pervious pavement site and5 there's buildings and there's roads. So what could6 happen and what often happens is when you put a road in7 this position where water is moving towards the wetland,8 you could get mounding on one side.9 THE PUBLIC: Can you just explain mounding?10 THE WITNESS: So let me go back to this one.11 So this is a normal flow path. Water is moving down12 gradient from high to low elevation. If I put a13 structure, this water would be blocked and it would tend14 to elevate and mound on the upgradient side because it15 has no where to go. So any time there's changes in16 development or just land use patterns on the site it17 changes hydrology. So if I build a road here I could18 make the water table higher upgradient and there's kind19 of a shadow effect where it's lower downgradient. So20 those are all the effects that happen with any kind of21 development as it relates to groundwater flow paths. So22 this is a complicated site, so it's hard to really23 estimate or describe what could happen but waters not24 disappearing, it's going somewhere.25 74 THE PUBLIC: Okay. It's going somewhere.1 So -- but it's not going to -- it's being drained away2 from your assessment of the site and gravity, etc., and3 the redirection of the stormwater patterns by the4 proposed stormwater management plan, that water is going5 away from the wetlands. Where is it going? It's going6 -- gravity right. It's going down the hill, to the7 gentleman's question that came up a few moments ago,8 it's going to flow the path of easiest resistance which9 is --10 CHAIRMAN BAGOFF: Let him testify. Ask him11 a question and let him testify.12 THE PUBLIC: Would it go down the hill?13 THE WITNESS: In this case, this is -- the14 blue was existing surface flow patterns and pretty much15 going to reflect what happens with the groundwater as16 well. So any time there's any new structure, that's17 going to change that path. So in this case even with18 the road, so even if this blue line surface water can be19 -- could be collected by the stormwater system,20 groundwater is going to be impacted because roads tend21 to be impacted or there's

n with18 the road, so even if this blue line surface water can be19 -- could be collected by the stormwater system,20 groundwater is going to be impacted because roads tend21 to be impacted or there's infrastructure in the road22 like storm sewer or sanitary sewer which end up either23 intercepting or blocking the groundwater flow pattern.24 So pretty much all these areas in the development are25 75 going to modify how water moves towards the wetland.1 And then cases like this, there's inherently increased2 volume of runoff on a development site and that's all3 being discharged to a point, one single point. So it's4 going to impact the stream downgradient. And to go back5 and look at the stream, it's in pretty nice shape. It's6 a pretty healthy stream typical of a natural area.7 There is not a lot of erosion, you know, the banks are8 low. Increased volumes going to cause that stream to9 either widen or to --10 THE PUBLIC: So that -- it's another11 question. If that stream is beginning to widen, and I12 am not sure if that's on a hill or if that's in a gully13 sort of area at the bottom of the hill, would that --14 could that form a new wetlands area?15 THE WITNESS: It could.16 THE PUBLIC: Okay. And so would that, if17 the development is not that far away from it how would18 the riparian zone then apply to a newly formed wetlands19 on a site due to the redirection of the water?20 THE WITNESS: One, the riparian zone is off21 of the stream channel, so that begins at the top of22 that, which would be here or there.23 THE PUBLIC: But what if the stream widens?24 THE WITNESS: It would shift at some point in25 76 the future where that riparian side begins. Now, they1 have a permit now, so that governs the riparian zone for2 now.3 THE PUBLIC: Okay.4 And it's only 50 feet right now?5 THE WITNESS: That's what I believe, yes.6 THE PUBLIC: Okay. Thank you.7 CHAIRMAN BAGOFF: Thank you.8 Any other members of the public have a9 question for Mr. Gallagher? Please come up and state10 your name.11 THE PUBLIC: Don Ershow. I live on Holmdel12 Lane in Roseland and I have a question specifically13 related to the flow of water in Canoe Brook.14 Could you go back to the map with the blue15 arrows. Is that dark gray the Canoe Brook on the left?16 THE WITNESS: That gray?17 THE PUBLIC: Yes.18 THE WITNESS: That's the headwater of the19 Canoe Brook.20 THE PUBLIC: That's the headwater of

ue15 arrows. Is that dark gray the Canoe Brook on the left?16 THE WITNESS: That gray?17 THE PUBLIC: Yes.18 THE WITNESS: That's the headwater of the19 Canoe Brook.20 THE PUBLIC: That's the headwater of Canoe21 Brook.22 MR. AFRAN: Let me just note for the record23 that's the stream to the far right of the drawing.24 CHAIRMAN BAGOFF: It's left.25