In a previous post, I talked about the news that HUD will begin scoring grant applications based on location efficiency, and using the LEED ND rating system to do so. While it is not yet clear what exactly HUD means by this, we can do our own exercise to look at the ND system, compare it to the existing built environment and see what locations in the Twin Cities might be eligible.
This isn’t just about HUD and their projects, it is a way of determining what the best locations are for new development that would ensure compact, contiguous development that makes the most efficient use of infrastructure and has multiple transportation options. Or in other words, it’s a method to begin planning a more sustainable region.
Before the analysis, a little background on LEED ND is appropriate:
- Smart Location and Linkage
- Neighborhood Pattern and Design
- Green Infrastructure and Buildings
- Innovation and Design Process
- Regional Priority Credit
The first three topic areas have prerequisites, or requirements that a project must meet in order to be eligible. All the topic areas have credits, from which a project proposer can choose to achieve to meet the various certification levels (Certified: 40, Silver: 50, Gold: 60, Platinum: 80).
While the LEED ND system is long and complex, there is really one topic area of the five in the rating system that deals with location and what land is off-limits versus eligible: Smart Location and Linkage (SLL). In this topic, there are five prerequisites and nine credits. For the purposes of this exercise, we’re going to be looking at just the prerequisites for LEED ND SLL, because once you get into credits, you have to start making lots of assumptions about how the project will be designed and what features it will contain. In addition, the other four topic areas deal primarily with the design of the project, or what is inside the project boundary, something we can’t know until a project is proposed. We want to know just what locations are at minimum eligible, and that means focusing on prerequisites in SLL.
Read on for the details of Smart Location and Linkage and the results.
Smart Location and Linkage Prerequisites (or most of them at least)
The five prerequisites for SLL are:
- Smart Location
- Imperiled Species and Ecological Community Conservation
- Wetland and Waterbody Conservation
- Agricultural Land Conservation and
- Floodplain Avoidance
The first prereq, Smart Location, is by far the most complicated, so I’ll skip it until Part 2 of this series. Trust me, it deserves it’s own post.
The other four prereqs in SLL basically each identify a feature associated with a particular geographic location that is off limits to development that wishes to qualify for LEED ND. The titles are mostly self-explanatory, don’t build where the environment is sensitive or unique critters live, don’t fill in or threaten waterbodies and wetlands, don’t use up protected and prime farmland and keep your development out of the 100-year floodplain. Many of these prereqs have caveats, or ways in which if you do impact the relevant feature, you can mitigate the impacts. For example, if your site does have an important ecological community, you can develop a habitat conservation plan which would allow you to meet the prereq. Again however, assuming we have no project details, we are going to pursue the spirit of the prereq, which is to avoid these areas all together.
For the most part, you can identify the features in the last four prereqs using publicly available spatial data. There are two exceptions: imperiled species and agricultural preserves. Finding imperiled species often involves a call to the DNR or Fish and Wildlife Service and maybe even a site visit, and as far as I can tell, there are no comprehensive surveys of these species that are mapped (if you know different, please let me know). In place of that, I used the Regionally Significant Ecological Areas data compiled by the DNR.
The second data gap is agricultural preserves for prereq #4. The prereq calls for avoiding “state or locally designated agricultural preservation district[s]”. While the state does have an agricultural preservation program to which landowners can opt in, the data on the locations of these lands is not public. Without that data, I used areas that were planned for agricultural use (assuming that almost all of these areas will likely not meet SLL prereq #1 anyway, and that planning an area for ag is a type of agricultural preservation in itself) and areas of prime ag soils that were not already developed.
What else is off limits?
There are a few other areas where you could not do a LEED ND project, but which don’t really come up in the prerequisites. For example, you couldn’t propose a LEED ND project in an existing park or designated open space. Likewise, the airport is likely not to be moving anytime soon. So, based on planned land uses, I identified these areas (along with the planned ag land talked about above) for exclusion from the eligible areas.
Ok, enough with the caveats, what do the data actually show?
What are the results?
Identifying land that is essentially “off limits” due to each of the four prereqs that are the subject of this post gives you four different layers: Significant Ecological Communities, Wetlands (with a buffer), Waterbodies (with a buffer), and 100-year Floodplains. Farmland is taken care of in the map described above (plus adding in some prime ag soils).
Combining these layers together Ian McHarg-style, you get a composite map showing areas that are not likely eligible for LEED ND given the requirements of SLL prerequisites 2-5 (again, we’ll cover prereq 1 in the next post in the series).
For the most part, these four prerequisites deal with natural environmental features (while #1 deals with man-made infrastructure), so the results don’t have clean lines and shapes. “Eligible” areas are often not contiguous, and are often fragmented by small pockets of in-eligible land. Fragmented and complex are not adjectives that developers generally like to see when searching for developable parcels. Most contiguous areas are present in the urban core, a function of most of the natural environment having been already altered (or destroyed).
In the next post, we’ll look at SLL prerequisite 1, which deals with man made infrastructure (streets and sewers) and combine those results with the analysis done here to identify the places in the Twin Cities that meet ALL the prerequisites of Smart Location and Linkage. If you buy the promise of LEED ND, this should show the most sustainable locations for development in the metro. Stay tuned.