NC v2.2 WEc1.1–1.2: Water Efficient Landscaping

You can do that. I have actually done it on one of our projects. However we also used a different mix of seeds for the turf, so it's more drought resistant to begin with. We also had no other permanent irrigation in place. If it's extremely dry, which at that location rarely happens, the turf just turns yellow. However you will need at least a letter from the landscape architect explaining that your turf can handle it. If you are planning on doing this in Arizona, when I doubt the reviewer will accept that.

Stephen,

I suppose this may be possible, however I do not believe GBCI considers well water to be non-potable, so it's probably a long shot.

Stephen, I believe that USGBC specifically rules out use of well water in the Reference Guide. I believe that for the purposes of LEED this would supersede the city definition. As Emily suggests it may be possible, though.

You may be able to account for the additional reduction. Potable waterPotable water meets or exceeds EPA's drinking water quality standards and is approved for human consumption by the state or local authorities having jurisdiction; it may be supplied from wells or municipal water systems. is defined as water that "...meets or exceeds EPA's drinking water quality standards..." Other users here on LEEDuser posted that they showed non compliance with EPA's standards in order to account for it.

Hi Victor,

Since you are using LOv2 it's possible the calculator you're using was created after the form you're using. So you could be right about a rounding issue. You could try filling out the form with all the right numbers (even though it doesn't match the calculator) and then uploading the calculator and a narrative with this credit. 

You could also submit a question through the feedback area of LEED-online to GBCI. 

Depending of the reduction of the potable waterPotable water meets or exceeds EPA's drinking water quality standards and is approved for human consumption by the state or local authorities having jurisdiction; it may be supplied from wells or municipal water systems. demand you can get 1 or 2 points under the LEED NC v2 system and 2or 4 under LEED NC v3. Your irrigation system can not achieve full points without using non-potable water for the irrigation.
For the time period, the reduction is base of a midsummer baseline. So a snap shut of the time with highest demand.
If you want to show the savings of your system than a study of savings based on midsummer conditions is probably most appropriate. I hope that helps.

The credit is designed for exterior irrigation. However you might be able to make the case to included it, but you probably should use a CIRCredit Interpretation Ruling. Used by design team members experiencing difficulties in the application of a LEED prerequisite or credit to a project. Typically, difficulties arise when specific issues are not directly addressed by LEED information/guide to clarify it.
The intent of the credit is after all the reduction of potable waterPotable water meets or exceeds EPA's drinking water quality standards and is approved for human consumption by the state or local authorities having jurisdiction; it may be supplied from wells or municipal water systems. consumption for landscaping irrigation.
I hope that help.

Benoit, is this a LEED-NC v2.2 project, or EBOMEBOM is an acronym for Existing Buildings: Operations & Maintenance, one of the LEED 2009 rating sytems.? You have posted to the NC forum.

If it's an NC project, then yes, you have a very simple and easy path to earning the 2 points.

Brett, my understanding is that you don't need to do that at all. The temporary irrigation is pretty much ignored since you are on a path to no irrigation.

Thanks Tristin. Most of the site landscape areaThe landscape area is the total site area less the building footprint, paved surfaces, water bodies, and patios. will be irrigated, but there is a substantial portion that will be natural restoration with tmeporary irrgation. We would like that area to be included in the calculations to meet the 50% irrigation reduction. Is the area still ignore in this instance?

I would count that natural restored area as not irrigated at all, since it's permanent systems that you're modeling for the credit. Make sense?

Thanks Tristan. I think I am confused as to how this can be expressed in the calculation spreadsheet or if it should at all. If the baseline design would have ground cover with average plants, density and micro-climate, how do include this square footage zero TWA thus reducing my percentage compared to the baseline? Thanks for your help.

Brett, can you be more specific about where you're getting hung up?

I am suggesting that the temporary irrigation should be ignored in your calculations. The baseline and design cases should highlight the reduced irrigation needs for the native landscape.

OK. This specific area, of several areas, is being restored with temporary irrigation and would otherwise be spray irrigated and have shrubs and ground cover that need regular water. We have reduced the need for irrigation to a temporary situation. Why would we not then receive credit to our irrigation reduction calculations to achieve the total site irrigation reduction of 50%? It would seem that we are not being credited for eliminating irrigation in this planting area because it doesn't fit in to the calculation spreadsheet. Maybe I am looking at this the wrong way.

Brett, I don't see any reason you shouldn't get credit for it, or any reason it shouldn't be reflected in the calcs. So I think I would need to see whatever you're seeing to understand your predicament. If you want to email me specifics, you can do so at tristan (at) leeduser.com.

Hi Kath,
Since the baseline case is really a theoretical landscape plan using "average values representative of conventional equipment and design practices" (Ref guide pg 121) it doesn't really matter what plantings or irrigation system was there before. I understand the credit is intended to compare your design case to what would "normally" be built, not to what actually was there before. Otherwise, you might be penalized for having a water conserving existing design.

Thus, the baseline irrigation system would not necessarily be an efficient rainbird system, but probably more of a guzzler, so you should be able to take credit for the better system in the design case.

It's left up to the design team's judgement to define what would be "conventional" plantings to list in the baseline case, which might be a combination of turf and other plantings. As for the prior parking spaces being demo'd and planted, this is an odd situation: since the baseline case needs to have the same total planted area as the design case, you probably have to assume those parking areas are also "planted" in the baseline case, which might reasonably be assumed to be turf grass.
Hope that helps!

Yongmei, the credit requirements here are twofold: use native/adapted landscaping, AND use no permanent irrigation. According to the LEED Reference Guide, any monoculture is not considered native/adapted. So whether or not turfgrass can survive without irrigation, it won't meet the credit requirements. You'll need to talk to your landscape designer about a more diverse landscape.

Tristan, thanks for your response. Hmm, the project already built, unfortunately the people who designed landscape for this project didnt pay attention... Now we have to fix it.

Anyway, we did design lots of native trees shrubs near our building. Are you sure that all the landscape have to be native, adapted? we have a project which has some turf grass and no irrigation system, ( but area of turf is not as big as our project) and it got 2 points. Does it depend on the type of turf?

yongmei - while Tristan's intent was correct from an ideal stand point - ie: native planting typically equates to a higher likelihood for compliance for no irrigation needs, the WEc1 does not "require" native/adapted planting. (note: native/adaptive could help with SSc5) With that said, the fact that you have turf grass means you will need to assess, given the rainfall for the site/local climate, whether the grass will survive without water. Aesthetics may come in to play too... we have had clients accept that grass at peak summer/heat may die off/turn brown, and they are ok with this... you may need to explain this to the reviewer, if questioned.

Since the lawn has been installed, and if you (or your client) determine irrigation is now "needed", then the fix can be to install a water efficient irrigation system... and accept only 1 point (or 2 points if you are using 2009). Or you could also add a stormwater collection system sized to irrigate the lawn based on appropriate calculations accounting for annual rainfall. My guess is this is too much added cost and/or site disruption, and you may need to forgo this credit.

Gunnar, thanks for your suggetion. Your guess is right, the client will not add irrigation system/ extra cost for this credit...

I am still wondering we might be able to explain somehow to reviewer because WE 1.2 in the V2.2 version requirement says "install landscaping that is not require permanent irrigation". We do have native trees/ shrubs, and this big SOD grass. If the SOD grass is drought-resistant type, and the client is ok if the grass turn brown at peak summer, then it is a ' landscaping that is not require permanent irrigation, right?

Is there anyone who did get the WE1.2 point with no irrigation on turf grass area?

Thanks

If you do not have irrigation, you meet the intent of the credit.

Mark, a lot of buildings use non-irrigated plantings for green roofs so the company you are keeping is a bit sparse. Your question is kind of tough to answer because so much depends on site and climate specifics. And then on the site, a roof is often more exposed to drying conditions (wind and direct sun) so the irrigation needs may be higher, but a higher baseline may also be justifiable. I would work with your landscape architect and use everyone's best knowledge and common sense. Tough to give more specific advice than that, at least for now.

No, calculations would not be necessary to document the credit in this situation.

There's been some good discussion of this topic (controller efficiency) on the LEED 2009 version of this forum.

Do you know what MasterFormat section they fall under? As far as I know, it would be Section 32, and included in the materials budget.

The project was bid and constructed under Masterformat 1995 (Divs 2-16). this was a renovation and the irrigation system serves a larger area outside of the LEED boundary. The modifications that were made to accommodate some site changes were contracted by the Owner and were not bid. We are tracking our material costs as actual construction costs and following MF 2004 divisions. The irrigation repairs fall under 32 80 00. I had assumed that we would include all of the plantings, paving, and other Div 32 items, but exclude soils and excavation along with other Div 31 items.

Alexia,

Your explanation above is sufficient....just an explanation of how the landscaping will be sustained during the establishment period, no need to explain where the water is coming from.

Thank you very much Gerren! We submitted the reply today.

Zarah, I'd suggest a landscape plan, with the legend and a written narrative that explains the design approach and your rational.

Also, please insure that you've met the requirements for WE 1.1. Some folks are missing the fact that TWO strategies are required by 1.1 and getting 1.1 is required to get 1.2

Rick, do you mean that it's a requirement to use at least  two things to earn WEc1.1, from the list of Plant species factorSpecies factor (ks) is a constant used to adjust the evapotranspiration rate to reflect the biological features of a specific plant species., Irrigation efficienc, Use of captured rainwater, etc.? Not sure I was aware of that.

Tristan,
From what we have determined, under 2.2, the "any combination" means that at least TWO of the methods must be utilized. This is a change from prior versions, where plant species alone would get you the credit. If it said "one or more" or "two or more" it would be more clear, but "any combination" is pretty clear in it's intent.

Still, the credit isn't terribly difficult, as we usually always install a high efficiency sprinkler system. However, if this system is only used for establishment (AND is then disabled) , the reviewer many not consider that as a valid claim.

As I read it, the intent is to encourage the use of alternate irrigation in an effort to encourage others to start to shift from potable waterPotable water meets or exceeds EPA's drinking water quality standards and is approved for human consumption by the state or local authorities having jurisdiction; it may be supplied from wells or municipal water systems. to rain water or other alternate sources.

The text of the credit follows:

Reductions shall be attributed to any combination of the following items:
❑ Plant species factorSpecies factor (ks) is a constant used to adjust the evapotranspiration rate to reflect the biological features of a specific plant species.
❑ Irrigation efficiency
❑ Use of captured rainwater
❑ Use of recycled waste water
❑ Use of water treated and conveyed by a public agency specifically for non-potable uses

Rick,

I actually disagree with your interpretation as requiring at least 2 of the reduction methods, although I am not sure it makes a difference since a combination is the easiest way to achieve a 50% reduction of calculated water budget.

To clarify your other point, you must show a 50% reduction in total water needs before applying non-potable waterPotable water meets or exceeds EPA's drinking water quality standards and is approved for human consumption by the state or local authorities having jurisdiction; it may be supplied from wells or municipal water systems. sources in order to achieve WEc1.2.

I'm confused - please tell me if I'm reading the above comments correctly: if we are not providing a permanent irrigation system under 1.2, we still need to complete the calculations to earn 1.1? Yet, the template (V2.2) simply lists the 4 options, and under Option #4 (no irrigation), there are no calcs listed. Aside from selecting the option, there isn't anything else to fill out, except describing the documents being uploaded.

So, what else are we supposed to complete for Option #4?

Roxanne, I don't think there is anything else for Option 4. The comments above are for a reduction in irrigation water, which is a different option.

Does that make sense?

Thanks for responding, Tristan.
You are correct, if no irrigation will be provided a water budget is not required.

Seems good to me—the permanent irrigation systems should effectively be uninstalled, which it sounds like these will be.

Brittany - I have used the same approach, but for clarity, it's not a "temporary" irrigation system. The components in a temporary system are above grade, so it's important to use the right terms with the irrigation designer, our you're likely to get a very different system. We are using this approach as research showed that when you combined the expense to keep the temporary system operating the traditional system was more cost effective. Most all city's require a double check valve (usually in a ground box), and removing this valve will render the system inoperable. There is no real need to remove the heads, but doing it certainly shouldn't hurt.

Keeping the main lines for hose bibs works well.

So, I'm with Tristan!

I had a project in which irrigation was already onsite. In order for our project to attain this credit, we had to remove the connection from the existing irrigation line to the water main to indicate we would not use it for more than 1 yr. So, you could keep the system in the ground, but render it useless, as the others have indicated.

Good question. We might have been referring to the one in LEED Online, but I'll have to check this and get back to you.

Yes, I checked on this and the LEED Online calculator for this credit has all the functionality you need to assess compliance. We recommend using it. I will update our above advice accordingly. Thanks for the note.

Not a problem. The issues on my project relate to size and I need to develop a summary spreadsheet in order to keep some sort of audit trail. It's a corporate headquarters renovation on a 150+ acre site that has local historic interest (previous corporate owner was a major automotive supplier). The site has been irrigated historically and we have added a pond for rain catchment that will accommodate all of the areas replanted with native and adapted species. We have excluded some existing buildings that will remain unoccupied until such time as alternative uses have been defined and prescribed our LEED boundary to 50 acres within the construction limits. I assume we should run our baseline case on the same 50 acres with the previous balance of turf grass, trees, etc. In accounting for irrigation, do we calculate turf areas to the trunk or dripline? Portions of the site lying outside the LEED boundary are held in various partnerships to retain the character of the existing property and limit development pressures. We have altered the landscaped areas within our LEED boundary to replace turf grasses with native and adapted plantings, added a signifcant amount of beds, etc. which should achieve WEc1.1. There are sentimental motives to continue turf irrigation practices to maintain some areas outside of the LEED boundary in their historic condition, but these would have to be fed by existing wells and upgraded pumps. Is there an acceptable approach to separate the existing rounds maintenance from our project landscaping to qualify for the Water reduction credits?

I think you already answered your own question—use the LEED boundary to exclude grounds maintenance practices that don't reflect on your project.

I think your question about trees is answered in this post on the LEED 2009 WEc1 forum.

Only "softscape" areas (classified by vegetation type) are included in the credit calculations. Non-irrigated rock gardens will reduce your water use, but are not part of the calculation.

Thanks Allison! Is there any specific credit language in the Reference Guide or elsewhere that I can point to that states this?

It's interesting that this is not more explicit in the Reference Guide, and it should be, I think. But, I think it's pretty clear, for two reasons.

1) The credit language gives the allowable ways to show water reduction, and not using plants is not one of them. This omission is continued through the Reference Guide on this credit and is intentional (although could be explicit).

2) If you were allowed to do this for rock gardens, where would it stop? Artificial turf, artfully designed concrete or asphalt, etc.? If you take it to the logical extreme it seems clear that not using vegetation is not within the credit intent.

Thanks Tristan!

Projects cannot take credit for non-irrigated areas. See NCv2.1 CIRCredit Interpretation Ruling. Used by design team members experiencing difficulties in the application of a LEED prerequisite or credit to a project. Typically, difficulties arise when specific issues are not directly addressed by LEED information/guide Ruling dated 3/23/2004 and v2.2 CIR Ruling 4/08/2009. Excerpts from these CIRs: “The strategy proposed could be achieved by virtually any project simply by manipulating the area for irrigation and is not acceptable to earn this credit.” AND “A project may not include planted areas in the irrigation calculations if these areas are intended to be left in a natural state, and not therefore require irrigation. Only landscaped areas can be included in the calculations for this project.”

Hope helpful!

Carlie,

Very helpful indeed. Our intent is not manipulation of the numbers, but rather to assure that our basis for calculations is internally consistent. We are renovating the principal structure in a multi-building office campus setting and the timing and program for subsequent renovations is not finalized so we are addressing those areas under the existing contract limits while anticipating future requirements and strategies to maintain the standards established in our initial renovation.

Thanks!

Same project, different question. We have created a pond on site that is around 27,000 sf to capture rainwater for irrigation use. Using the EPA Water Budget Tool, we haven't classified this as a "hydrozone" as it is not factored into the Evapotranspiration figures (evaporation yes, transpiration no....) What's the proper way to classify this area so we can get rid of the error message telling us our Base and Design case areas don't match?

You are correct in excluding the pond as a hydrozone. The pond area should also be removed from the landscaped area total. If I am understanding you correctly, this should result in landscaped areas that match in the basecase and design case.

The 0.7 acre pond is new and located within a five acre area that was primarily irrigated turf grass in the base case. My dilemma is we have to include the pond surface if the areas for the Base and Design cases are to match. We are replacing a large area of irrigated turf with non-irrigated native meadow, so the water reduction requirement is met, the puzzle is how to characterize it.

For the purposes of calculating this credit, the baseline is not the site prior to construction, but rather convential landscaping practices. This applies to the project site assuming that the landscaped areas improved as part of your project would be landscaped even if this wasn't a LEED project, but would be done so in a less than ideal way.

Essentially, you don't get credit for removing irrigated turf if you aren't replacing with lower water using species and/or irrigation equipment, just like you don't get credit for removing turf to replace it with a parking lot. The pond area doesn't count for or against you and should not be included in either the baseline or design case.