Hi everyone - just reviewing the credit definitions again for our coastal development. Would you say the requirement of 30 meters from a water body is taking into account what water level? Would it be the Highest Astronomical Tide (HAT) conditions or would you recommend an alternate water edge?
Also, reviewing the definition of a wetland that notes: an area that is inundated or saturated by surface or ground water at a frequency and duration sufficient to support, and that under normal circumstances does support, a prevalence of vegetation typically adapted for life in saturated soil conditions. Wetlands generally include swamps, marshes, bogs, and similar areas, but exclude irrigation ditches unless delineated as part of an adjacent wetland.
Because it notes Surface / Groundwater, can I assume intertidal areas supporting saltwater mangrove species are not considered as wetlands?
Blake Jackson
Director of SustainabilityNORR
LEEDuser Expert
7 thumbs up
July 27, 2020 - 8:54 pm
Greetings! Let me respond to your inquiry one at a time:
1) The "30m from a water body requirement" should be considered for resiliency purposes - protecting the asset as well as access to the coastline as an open space buffer. I agree that the HAT definition for this should be used. Coastal sites are tricky, as some come with a controlled edge (i.e. a sea wall that demarcates a definite edge from which one can draw a 30m line from), and others are ill-defined (meaning they edd and flow with tidal cycles and can change throughout the day). If you have the first type, this is easy; just demarcate a 30m line from the edge of the sea wall on a site plan. It sounds more like you have the second type, and in this instance, I would certainly use HAT. Note: for LEED documentation purposes, I would draw a line on a map to demarcate the HAT line and clearly show a line offset from this 30m (or greater) for compiance.
2) Wetlands definition: Mangroves are a halmark of coastal wetland habitats and should be maintained/preserved as part of this credit without a doubt. They stabilize soil, clean water, prevent erosion and are an integral biohabitat. The sole purpose of this credit is to preserve, conserve and protect such areas! This does not completely eliminate "all" development in these areas - just major buildings, parking lots, etc. LEED allows "minor improvements" to such areas, including clearnings, grading, brownfield remediation, bike/walknig paths, small structures (single-story, <45m sq.) etc. (see LEEDv4 for a full explanation of specifics regarding "minor improvements").
Senna Sabir
Arcadis2 thumbs up
July 28, 2020 - 10:03 am
Hi Blake.. Brilliant - thank you for your response. Yes thats along the same lines we're thinking, great to have that sanity check.