To earn this credit, you’ll need to reduce your use 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. for irrigation by 50%–100% compared with a baseline irrigation system typical for the region. Because landscape irrigation can account for nearly 40% of the average office building’s potable water consumption, reducing or eliminating potable water use for landscaping can save a lot of water, and money.
Planting native or drought-tolerant plants, retrofitting existing irrigation systems, installing high-efficiency irrigation technologies, and reusing graywaterGraywater is untreated household waste water which has not come into contact with toilet waste. Graywater typically includes used water from bathtubs, showers, bathroom wash basins, and water from clothes-washer and laundry tubs, though definitions may vary. Some states and local authorities also allow kitchen sink wastewater to be included in graywater. Project teams should comply with the graywater definition established by the authority having jurisdiction in the project area. for landscape irrigation will all help you make strides toward this credit while also reducing maintenance costs. You’ll need to make investments to implement some of these strategies, but many municipalities provide incentives for efficient irrigation technologies and controls.
Even in arid climates, choosing landscape plantings carefully can reduce or eliminate the need for irrigation. City of Flagstaff
Start by conducting a walk-through of the irrigation system while it is in operation. Basic problems like leaks, faulty and broken components, and overwatering are easy to identify and fix. To reduce the need for irrigation, choose landscaping that is compatible with the site’s climate and microclimate, sun exposure, soil type, drainage and topography. In hot, dry climates, focus on drought-tolerant plants and xeriscaping, while reducing or eliminating turf grass. If turf grass is necessary, select a species that can endure periods of drought.
In hot, humid, and temperate climates, use native plants alongside weather-sensitive irrigation systems or moisture sensors to avoid unnecessary watering. Using captured rainwater can help eliminate the need for potable water in landscape maintenance. In cold climates, the project team should install hardy, native plants and trees that will survive through the winter months.
Because irrigation practices differ widely among regions and building types, there are a variety of strategies for maximizing water-efficient landscaping practices and assessing and documenting compliance with this credit. Your available choices will depend on the systems already in place on your building site and your ability to modify or replace those systems if necessary. Additionally, local and municipal restrictions, incentives and support resources will vary significantly from location to location. Carefully review the compliance options and methodologies described in the LEED-EBOMEBOM is an acronym for Existing Buildings: Operations & Maintenance, one of the LEED 2009 rating systems. Reference Guide to determine the appropriate best practices for your situation.
You might be able to use Option 1 but here are the couple of constraints.
Yes, if 100% of the water used is from reclaimed water, graywater, or harvested rainwater, the project is eligible for all five points. Use the alternative compliance path on the LEED Online form and include an explanation of the situation along with a signed letter by the property manager, facility manager, or owner verifying the use of non-potable water.
This isn't necessarily an easy thing to do, but a landscape architect could help you identify a rough sketch of conventional landscaping for the region, and then your landscaper could help estimate how much water per square foot they would recommend for that type of landscaping. You might also touch base with local water conservation organizations or groups promoting xeriscaping. Keep in mind that Option 2 is open to all buildings but you can’t mix and match the calculations: you can’t develop a theoretical baseline according to Option 2 and then compare that to your metered data for July.
There's a compliance path for just this type of situation. As long as the property's landscaped area is equal to at least 5% of the total site area, the credit language and other documents state you are eligible for the credit. If the project is registered, check out the form in LEED Online for how to document compliance based on zero use of irrigation (and if it's not registered yet, it's a good idea to do so and always look at the LEED Online forms early on to get a full sense of the compliance and documentation options). Also note that you'll need to make sure there's no regular hand-watering going on, as sometimes even if there's not a permanent irrigation system the grounds are still regularly watered.
Determine whether at least 5% of the building’s grounds are vegetated, which determines eligibility for this credit. Planters and rooftop or courtyard gardens qualify as vegetated space, so consider adding them to offer occupants an amenity and bring this credit within reach.
Establish the LEED baseline for irrigation water consumption using historic metering data, empirical calculations or theoretical calculations, or an independent irrigation performance and ranking tool. Procedures for performing these calculations are described in the LEED-EBOM Reference Guide.
Assess current irrigation levels, compare with the calculated LEED baseline and identify opportunities for reduction. Collaborate with landscape maintenance contractors, irrigation system vendors, or landscape architects for best results.
Conduct a walk-through of the irrigation system while it is in operation. Look for broken or leaking pipes or sprinkler heads, and sprinklers spraying on sidewalks, roads, and buildings. Fixing these problems can be easy and offers immediate savings.
Eliminating potable water used for irrigation on the entire site or at least a portion of it is an effective strategy for earning this credit. Consider whether your area gets enough rainfall to provide an acceptable amount of natural irrigation.
Eliminate unnecessary water use by Use of drip irrigation helps to conserve water. BuildingGreen Imageoptimizing irrigation schedules. Retrofit the irrigation system with weather-based controls that conserve potable water, including moisture sensors and weather-center communication. Replace conventional irrigation systems with high-efficiency systems such as drip irrigation.
Weather-based controls carry a minimal cost and will reduce excessive water use and overall maintenance costs. A drip-irrigation system would also reduce water use while requiring a low to moderate investment.
Use native, drought-resistant species in place of turf grass. Convert portions of the site to natural areas that do not require landscaping or additional irrigation. Replace annuals with native or adaptive perennials that require less water. Introduce native understory plants rather than grass turf under trees to reduce the need for additional irrigation.
Conversion to native species for existing landscaping is relatively low-cost and may also reduce maintenance costs.
Use mulch and compost to improve soil quality by adding organic matter, reducing the need for additional irrigation.
Install stormwater retention systems such as cisterns, retention ponds, and bioswales, to provide non-potable means of irrigation.
Sub-meter irrigation systems to track water consumption and efficiency. Review irrigation system sub-metering records to check for leaks or other malfunctions that may be leading to excessive use of potable water.
Perform data collection or calculations based on your chosen compliance path and credit requirements.
A graywater collection system or other source of non-potable water may require a moderate investment unless a readily available source exists, such as a municipal water reclamation plant.
It may be tempting to determine a baseline irrigation use by using the calculation methodology for Option 2 and then compare that value to the actual metered irrigation data but that is not allowed. The calculation methodology must be consistent between the baseline and installed cases.
Make sure that monthly meter readings are performed on irrigation subsystems.
Where submetered irrigation water use data is required, note that the regional growing season, including the month of July, must be included in the data set.
Implement a preventative maintenance program to maintain the operational efficiency of the irrigation system.
Ongoing data collection and preventative maintenance will be no- or low-cost initiatives.
Excerpted from LEED 2009 for Existing Buildings: Operations & Maintenance
To limit or eliminate the use 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. or other natural surface or subsurface water resources available on or near the project site for landscape irrigation.
Reduce 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. or other natural surface or subsurface resource consumption for irrigation compared with conventional means of irrigation. If the building does not have separate water metering for irrigation systems, the water-use reduction achievements can be demonstrated through calculations. The minimum water savings percentage for each point threshold is as follows:
For buildings without vegetation or other ecologically appropriate features on the grounds, points can be earned by reducing the use of potable water for watering any roof and/or courtyard garden space or outdoor planters, provided the planters and/or garden space cover at least 5% of the building site area (including building footprintBuilding footprint is the area on a project site used by the building structure, defined by the perimeter of the building plan. Parking lots, parking garages, landscapes, and other nonbuilding facilities are not included in the building footprint., hardscapeHardscape consists of the inanimate elements of the building landscaping. Examples include pavement, roadways, stone walls, concrete paths and sidewalks, and concrete, brick, and tile patios. area, parking footprintParking footprint refers to the area of the project site occupied by the parking areas and structures., etc). If the planters and/or garden space cover less than 5% of the building site area, the project is ineligible for this credit.
Three options are available to demonstrate compliance with the above requirements. Project teams that do not separately meter their actual irrigation water use during the performance period must choose Option 2.
Choose 1 of the following options:
Calculate the baseline irrigation water useBaseline irrigation water use is the amount of water used by conventional irrigation in the region. by determining the water use that would result from using an irrigation system typical for the region using the mid-summer baseline case or the month with the highest irrigation demand and compare this with the building’s actual irrigation potable water use, which can be determined through submeteringSubmetering is used to determine the proportion of energy use within a building attributable to specific end uses or subsystems (e.g., the heating subsystem of an HVAC system).. Use the baseline and actual water use values to calculate the percentage reduction in potable water or other natural surface or subsurface resource use. More detail about completing this calculation is available in the LEED Reference Guide for Green Building Operations & Maintenance, 2009 Edition.
Calculate the estimated irrigation water use using the mid-summer baseline case or the month with the highest irrigation demand by determining the landscape areaThe landscape area is the total site area less the building footprint, paved surfaces, water bodies, and patios. for the project and sorting this area into the major vegetation types. Determine the reference evapotranspiration rate (ET0 ) for the region and determine the species factorSpecies factor (ks) is a constant used to adjust the evapotranspiration rate to reflect the biological features of a specific plant species. (ks ), density factorDensity factor (kd) is a coefficient used in calculating the landscape coefficient. It modifies the evapotranspiration rate to reflect the water use of a plant or group of plants, particularly with reference to the density of the plant material. (kd) and microclimate factorMicroclimate factor (kmc) is a constant used in calculating the landscape coefficient. It adjusts the evapotranspiration rate to reflect the climate of the immediate area. (kmc ) for each vegetation type. Use this information to calculate the landscape coefficient (KLThe landscape coefficient (KL) is a constant used to calculate the evapotranspiration rate. It takes into account the species factor, density factor, and microclimate factor of the area. ) and irrigation water use for the design case. Calculate the baseline case irrigation water use by setting the above factors to average values representative of conventional equipment and design practices. Use the estimated and baseline case to determine the percentage reduction in potable water or other natural surface or subsurface resource use. Factor values and other resources for completing these calculations are available in the LEED Reference Guide for Green Building Operations & Maintenance, 2009 Edition.
If independent irrigation performance and ranking tools are available from local, regional, provincial, state, territorial or national sources, use such tools to demonstrate reductions in potable water or other natural surface or subsurface resource for irrigation purposes.
Specify water efficient, climate-tolerant native or adapted plantings. Implement or maintain high-efficiency irrigation technologies, such as microirrigation, moisture sensors or weather data-based controllers. Feed irrigation systems with captured rainwater, gray water (on-site or municipal), municipally reclaimed water or on-site treated wastewater. Consider not operating an irrigation system. Consider employing xeriscapingXeriscaping is a landscaping method that makes routine irrigation unnecessary. It uses drought-adaptable and low-water plants as well as soil amendments such as compost and mulches to reduce evaporation. principles in arid climates.
Additionally the credit can be met when landscape irrigation is provided by raw water (excluding naturally occurring surface bodies of water, streams, or rivers, and ground water) that would otherwise be treated specifically for nonpotable uses. Only ponds designed solely for the purposes of stormwater retention or detention can be used for this credit.
1. 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 is suitable for drinking and is supplied from wells or municipal water systems.
This book explores the design and management of landscape irrigation systems. It provides coverage of irrigation system design, with a focus on water conserving methods. Stephen W. Smith (John Wiley and Sons, 1996)
ARCSA was founded to promote rainwater catchment systems in the United States. Its website provides regional resources, publications, suppliers and membership information.
CIT is an independent research and testing facility providing information to designers, manufacturers and users of irrigation equipment.
This website offers a database of more than 7,000 native plants in North America.
This resource provides information on introducing native species into the understory of landscaping trees.
EPA's WaterSense site offers a couple of useful resources, including a native plants reference, and reference evapotranspiration information useful for the Option 2 calculation.
Use this diagram to understand your documentation needs for this credit.
Screenshots of the LEED Online forms for WEc3 with sample data and tips on Option 2.
The following links take you to the public, informational versions of the dynamic LEED Online forms for each EBOMEBOM is an acronym for Existing Buildings: Operations & Maintenance, one of the LEED 2009 rating systems.-2009 WE credit. You'll need to fill out the live versions of these forms on LEED Online for each credit you hope to earn.
These links are posted by LEEDuser with USGBC's permission. USGBC has certain usage restrictions on these forms; for more information, visit LEED Online and click "Sample Forms Download."
We are in the PP but do not have our low-water landscaping installed. A contract will be signed to install it prior to the end of the PP. Has anyone obtained the credit this way? The client's landscape architect said we could. I think that only works for LEED BD+C. Anyone out there have experience with this? Thank you.
Is the design complete? If so and if the contract gets signed to do the work during the performance period, I could see GBCI considering this approach but I haven't seen this type of strategy approved in the past. If the installation timeline is relatively short like less than 3 or 4 months, another strategy would be to submit this credit during the final review phase. I think that approach would have a better chance of success.
I am attempting to calculate the baseline for irrigation, and came across an EPA Watersense Water Budget tool that can be used to determine the water efficiency of landscaping. For this tool, they determine the irrigation baseline by using the local evapotranspiration rate (determined by zip code) multiplied by the landscaping area. Do you have any knowledge if this EPA tool meets the 'soundness of calculation' requirement to determine the baseline for this credit?
The Watersense tool is used to establish the baseline for irrigation in v4. But, if you're pursuing Option 2 for v2009 I would think that you'd need to stick with the theoretical calculation on the v2009 LEED form. Are you interested in using the Watersense tool because the outcome is more favorable or easier to use?
What is LEED's stance on AstroTurf? I have a building that replaced all of their grass with this and am curious if it is now considered hardscapeHardscape consists of the inanimate elements of the building landscaping. Examples include pavement, roadways, stone walls, concrete paths and sidewalks, and concrete, brick, and tile patios..
Hi Gwen - Yes, AstroTurf would be considered hardscapeHardscape consists of the inanimate elements of the building landscaping. Examples include pavement, roadways, stone walls, concrete paths and sidewalks, and concrete, brick, and tile patios..There doesn't appear to be any published guidance from USGBC or GBCI on this, but from what I can tell from several artificial turf manufacturer's websites, AstroTurf would be considered hardscape. Below is a link for one of these websites.
I hope this helps!
For a project where turf grass area is replaced by native low-irrigation demanding planting would baseline landscape type include turf whereas design type include the new water efficient species? Obviously, if this is allowed, a greater reduction in water use is achieved.
If a comparable development in the area would normally use turf, and you are utilizing a vegetation type that is more water efficient, it is perfectly acceptable to use turf in your baseline, and the more efficient plant material in your design case. The only requirements, per se, are that the total irrigated areas and the microclimate factorMicroclimate factor (kmc) is a constant used in calculating the landscape coefficient. It adjusts the evapotranspiration rate to reflect the climate of the immediate area. be consistent between the two cases.
Keep in mind, the baseline case is defined as the typical development in the area. Your project can deviate completely from what is the norm, so it's not uncommon to have different vegetation between the two cases.
Than you William!
If we install subsystem metering for the irrigation systems to comply with WEc1 can we follow the “Non-Metered Irrigation” option at WEc3? This is because historical data are not available since the subsystem metering was installed only prior to commencement of the performance period. However, it seem quite contradictory when selectin the “Non-Metered Irrigation” option which is determined as the case when “Irrigation systems are not metered separately from other water subsystems at the project building and associated grounds”. Has anyone ever experienced this issue before?
Yes, this actually isn't all that uncommon a problem as many teams will install irrigation sub-metering systems toward their EBOMEBOM is an acronym for Existing Buildings: Operations & Maintenance, one of the LEED 2009 rating systems. certification efforts, but historical separately metered data does not exist to define the baseline. In this case, just provide a narrative under 'Special Circumstances' explaining that while an irrigation sub-meter has been recently installed, there is no historical sub-metered data to define a base case from, and you are therefore approaching the credit using the non-metered compliance path.
Thanks William for the quick reply!
I have a question about a variation of this question. My client has had irrigation sub metered for many years. We want to pursue this credit and know that we need to replace most of the landscaping. We are in the performance period now and the landscaping is not yet installed. Their landscape architect told them that they can pursue the credit using Option 2 as long as there's a signed contract to begin the installation of the landscaping by the end of the performance period. Has anyone else found this to be a plausible way of meeting the credit? Thank you.
I do have an irrigation system that uses 100% of 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.. Do i still need to prove by calculations the potable water use reduction? The irrigation system has no sub metering.
I would like to know if there is any special validation to my situation:
We used to have irrigation from the faucets, what means an irrigation with 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., but we are attempting to get the 100% reduction of potable water irrigation. That's why we placed a policy that forbids the irrigation with potable water; and we are implementing water storage tanks to harvest rain water and replace our irrigation source.
My question is if there's any way to certify this technique without having to fill the 3 possible options. Because we don't have an historical data to achieve option one. And considering a 100% reduction, I would think it will be obvious that the scope is being done.
You're right Maxmilliano - The v2009 template doesn't have an obvious pathway for documenting a site that employs 100% non-potable (and, don't forget - natural surface or subsurface resources) water for irrigation. I'd recommend using the Alternative Compliance Path option, and providing detailed documentation as to your water sources, vegetation, etc...
A number of college campuses here in California have used this approach - GBCI won't be at all troubled by it.
Hope that helps,
I'm on a college campus trying to document this at the campus level. We are using Option 1 comparing submetered irrigation to the "conventional, expected irrigation" baseline. We have, however, several campus areas that we are not irrigating (forested, native/adapted, or turf we don't care to water). When setting a "conventional irrigation baseline" should that baseline assume that, conventionally, 100% of turf and landscaped area would be irrigated? Or would we only calculate the conventional irrigation rates over the area that we are irrigating. It sort of seems like we should get credit for not irrigating those areas but I don't want to over estimate the baseline. Thanks.
Are there any significant changes in the baselines for WEc3 between NC 2.2/2008 and EBOMEBOM is an acronym for Existing Buildings: Operations & Maintenance, one of the LEED 2009 rating systems. 2009?
The project is in a desert location with a large xeriscape mono-surface area, it's being built to NC and will then be certified under EBOM. It's assumed that the credit from NC will flow cleanly into EBOM, would any additional calcualtions/considerations will be required?
If you check the latest form V5, you will find, if submeteringSubmetering is used to determine the proportion of energy use within a building attributable to specific end uses or subsystems (e.g., the heating subsystem of an HVAC system). for irrigation is installed, option 2 is not allowed. Which means, you have to use either option 1 or option 3.
So the answer to your question depends on if the submetering for irrigation installed:
1, if installed, you need to use different baseline
2, if not instaled, baseline not chanced compared to LEED NC2.2
P.S. My observatoin of LEED V5 form shows different direction from the Q&A above (indicating Option 2 is always an available methodology). Someone may help to confirm which one is correct. Thank you!
Hi, We are using 100% treated waste water for irrigation. It is not sub metered and therefore we are trying to use the option 2. We are using a baseline case of "Hose without water gun" that is the common mode of watering in this part of the country.
There are 2 problems:
1. How to estimate the irrigation efficiency of the hose without water gun?
2. I think whatever the IE for baseline, we still should achieve 100% water use reduction because we use 100% 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.. But for some reason online submission form does not calculate it that way. For example if I use 0.5 IE for baseline and 1.0 IE for treated waste water, I get a water use reduction of 50.5%.
Can you please advise me on where I'm going wrong.
You may not have to worry about the inputs to the theoretical calculation if your treated wastewater is more or less unlimited, like provided through a municipal system. In that case I've seen projects that were able to confirm compliance with a signed letter from the building owner or management confirming that 100% of the water is treated wastewater.
But if it's treated wastewater from the building, and therefore limited, then it becomes more important to estimate the mid summer baseline and show how much treated wastewater is available at the same time.
To your questions above, I haven't seen official guidance for the IE for hand watering, but I have seen a project use a lower efficiency of 0.5 for a similar scenario. Also, to account for the nonpotable waterNonpotable water: does not meet EPA's drinking water quality standards and is not approved for human consumption by the state or local authorities having jurisdiction. Water that is unsafe or unpalatable to drink because it contains pollutants, contaminants, minerals, or infective agents. use, rather than adjusting the IE, there is a spot on the form to enter in the non-potable water applied, below the installed case calculation.
Dear Ben, Thank you for the reply. In our case the treated waste water comes from onsite (toilet flushing and canteen waste water). We are able to theoretically calculate that waste water is actually more than the irrigation water demand.
But my concern is that on the online submission system, there is no provision to show them. And as you said there was the option to indicate 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. use in the earlier versions of the forms, but version 5 has removed that option it seems.
Hi, our project has no permanent irrigation but has periodic hand-watering as needed for extreme weather conditions. When I go to complete the LEEDonline form I am not asked anything further concerning the hand-watering. The comment from the FAQs above
"Also note that you'll need to make sure there's no regular hand-watering going on, as sometimes even if there's not a permanent irrigation system the grounds are still regularly watered."
suggests that the project should track/calculate/measure in some way? Although LEEDonline only asks to confirm no permanent irrigation (in this project situation there is not) and to provide a letter of confirmation from the facility management. This statement in the FAQs is slightly confusing. I just want to be sure there is nothing more for my project to include.
If your project is only hand-watering on an as needed basis during periods of extreme weather conditions, then you should be okay in claiming no permanent irrigation.
What the comment is referring to is routine hand watering. If landscapers, maintenance crew, or other are routinely hand watering the vegetation on a scheduled (daily/weekly) basis, then it would be considered the same as regularly irrigating.
I'm looking for a calculator or guide that would suggest how much rainwater could be collected in Mid-summer or the month with the highest irrigation demand. We have a 3000 gallon cistern in the Pacific northwest. I would guess that the tank would be considered dry in the summer but it would be great to confirm. Thank you for any advice.
Karin, I don't know of a single good resource on this. I would ideally consult with an engineer.
Contech's rainwater harvesting runoff reduction calculator will help you with monthly supply/demand optimization:
I am not affiliated with Contech, but I like this tool. I hope it helps you. Feel free to contact me to discuss further.
Thank you! The calculator is super helpful.
My team and I are in the appeal phase for our project.
WEc3 was denied because the total area of exterior landscaping is 3,276 square feet, which is less than 5% of the total site area and therefore the project was not eligible for this credit.
The team wants to increase the exterior landscaped area to 4575.8 sf, making us eligible for the credit.
This landscaped areas will be modify now (as tomorrow), and we would like to know whether it is permissible to modify the landscaping, have a contract will an designer and have only 50% advance in the landscape project at the moment of submitting the appeal.
Would this be acceptable? Or the 100% of the project should be finished at the time of the final submittal?
Thank you in advance for any comments.
Did the final review comments provide any instructions for an acceptable course of action in the event of an appeal? I recommend trying to contact GBCI about your proposed approach before you spend time and money modifying the site.
Interesting question and what is GBCI final review comment? Thank you!
Our project has installed water meters for Irrigation just recently at the start of performance period. The project uses 100% of treated water for Irrigation which is metered. Metered data is available only for 6 months.
1. Should the project comply with the requirement by using option 1? but there is no conventional irrigation system rate available which is required to calculate baseline.or
2. Should the project use option 2 and do manual calculation to prove compliance? but second option is available only for non metered irrigation which is not true in this case. Or
3. Should the project use alternative compliance path?
Option 2 with the theoretical calculation can still be used by teams that have an irrigation meter. The only caution is that you can't compare the metered irrigation use to the theoretical baseline calculation. Instead the comparison has to be between the theoretical calculations for both the baseline and installed cases.
Some portions of the site are irrigated, while other areas are not. Non-irrigated areas include adapted grass,shrubs and trees which are shaded by the building and do not need irrigation. There is also a grassy area which does get irrigated.
How do I enter this into the LOL form? If I enter "0" in the IE column, then the TWA = 0 for that row. Is it acceptable to enter the non-irrigated areas on a separate row and enter IE = 0 to get zero Total Water Applied for those areas?
What documentation would I need to provide to support this? A signed statement from the owner? Irrigation is performed by hose and sprinkler, so I can't show that there is a permanent irrigation system that excludes those areas. Any thoughts?
Lyle - That's a tough one. The answer to the first part is fairly clear to me - you should definitely include the area of any landscaped area that does not require irrigation due to the nature of the vegetation. In a perfect world, everyone replaces their turf grass with native/adapted vegetationAdapted (or introduced) plants reliably grow well in a given habitat with minimal winter protection, pest control, fertilization, or irrigation once their root systems are established. Adapted plants are considered low maintenance and not invasive. that doesn't need irrigation - the credit certainly should reward instances where that is the case. A detailed site plan showing the various vegetation types would be key to that submittal.
That being said, I'm not sure how to go about documenting an irrigation approach that involves a hose and sprinkler. Assuming there's no water meter data, you'd need to really help the reviewer feel confident that you know exactly how much water you're using with that equipment.
Hope that helps at least a little,
Thanks for your insight, Dan. I’m assuming that Option 2 (theoretical calculations) can be used successfully in this case to demonstrate the usage of irrigation water. I am planning on listing the shaded landscaped areas that do not receive irrigation separately from the irrigated areas in the LOL form. For the non-irrigated areas, I have set IE=0. This is the only way that I have found that I can get zero Total Water Applied (0 TWA) for those areas. Do you think that this approach (described in a narrative) will be acceptable?
As always, thank you for your time, Dan.
Hopefully this doesn't come too late to be of use to you. But, regarding the non-irrigated areas, I have had success on prior projects using the methodology you propose (setting IE=0 to achieve a TWA of 0). In the table on the credit template, we simply indicated "non-irrigated vegetation" for the landscape type. No additional documentation was required aside from the landscape plan.
Thank you very much, William. That is helpful to this, and future, projects.
The intent of the credit says "To limit or eliminate the use 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. or other natural surface or subsurface resources available on or near the project site for landscape irrigation."
I have two questions: Can we get credits for using a beachwell (a well drilled on a beach and drawing seawater) and desalinating this seawater for use in landscaping?
And question two: What "potable water" we are talking about? The source (seawater) is nonpotable, but if we desalinate it, it becomes potable.
Vincent, in my opinion, this could meet the definition of nonpotable waterNonpotable water: does not meet EPA's drinking water quality standards and is not approved for human consumption by the state or local authorities having jurisdiction. Water that is unsafe or unpalatable to drink because it contains pollutants, contaminants, minerals, or infective agents. use. You are making use of a nonpotable water source, and treating it to the standards needed in the building. Other more common nonpotable sources, like graywaterGraywater is untreated household waste water which has not come into contact with toilet waste. Graywater typically includes used water from bathtubs, showers, bathroom wash basins, and water from clothes-washer and laundry tubs, though definitions may vary. Some states and local authorities also allow kitchen sink wastewater to be included in graywater. Project teams should comply with the graywater definition established by the authority having jurisdiction in the project area., would require similar treatment.
The energy required to desalinate the water will count against you in the EA category, of course.
Tristan, thank you for your elucidating clarification. On energy, we are thinking about wind turbines to keep our head above water in the EA category.
Just to follow Tristan's comment here - the credit language is more broad than just 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.. It includes " . . . other natural surface or subsurface resource consumption . . . " which would seem to encompass seawater or a beachwell. I'm actually struggling with how this relates to the fundamental intent of the credit - its a really interesting question ecologically, as using desalinated seawater could theoretically be better for 'the environment' than using potable water, even with the associated climate impacts. (It could just as easily be worse, of course.) But it gets very complicated very quickly, and if I were making a decision with LEED in mind, I think the much safer assumption is that the language around other natural surface water would apply and the desal approach would not be approved.
And I agree with Tristan completely - even with wind turbines associated, that energy penalty is going to be an albatross . . .
The Reference Guide does not state the irrigation efficiency for manual watering, just for drip and sprinkler irrigation. Is 0.5 an acceptable irrigation efficiency for manual watering with a hose?
our project is very near to a river and our client is proposing to make a 25m deep drill and pump water (which is not potable due to the river) and use it for irrigation purposes. I know that a well drilled just for irrigation purposes does not meet intend of this credit but the water cannot be marked as potable - part of the river in the city centre of Belgrade - Serbia. What do you think? Thank you in advance for any suggestions.
Hi Jiri - I think the language of the credit would preclude that approach. The targeted water includes both 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. and 'other natural surface or subsurface resource.' A river sounds like natural surface water to me.
Hope that helps clarify,
I'm curious on what everyone thinks about permeable areas covered with gravel; are these considered landscape areas and account for the 5% landscape area requirement?
That's an interesting question and I dare say the answer won't be entirely black & white. I think it fundamentally requires you to ask yourself what the intent of the specific area is. A gravel parking lot, for example, is not landscaped area, nor would it be irrigated in a 'conventional' scenario. On the other hand, if the gravel area is part of the functional landscaping (I'm thinking here of something akin to xeriscapingXeriscaping is a landscaping method that makes routine irrigation unnecessary. It uses drought-adaptable and low-water plants as well as soil amendments such as compost and mulches to reduce evaporation.) and the gravel ostensibly replaces what might otherwise be turf grass on a more conventional site, then yes, I would include it. It really comes down to what purpose the gravel area serves.
I'm working on a building with a large portion of natural vegetation which is not irrigated. There is also a separate area of turf, trees, shurbs that is irrigated. Should the calculations take all areas into account, or only the landscaped areas with irrigation?
Absolutely include the non-irrigated natural vegetation Michael. In a perfect world, EBOMEBOM is an acronym for Existing Buildings: Operations & Maintenance, one of the LEED 2009 rating systems. would inspire all building owners to keep their vegetated areas with natural vegetation that does not require irrigation. The fact that it is not actively maintained or 'landscaped' is a positive, not a negative.
I just wanted to make sure since the pulldown menu did not include "No Irrigation" as an option.
Just to update, I submitted using the natural vegetation and the credit was denied. We received the following comment:
"...only landscaped areas may be included in the calculation. Natural areas that are not irrigated must be excluded."
Yikes - I dare say the folks at LEEDuser should retract my expert status given a review comment like that one. My apologies Mike. I spoke to someone at GBCI about this topic recently and I think I failed to consider the various scenarios by which 'natural vegetation' might be present on site. If an area has been in a natural vegetative state for an extended period of time, GBCI doesn't believe that simply preserving the status quo merits credit in terms of irrigation water use. On the other hand, if that area were restored to a natural state from an alternative use, particularly a conventional landscaping scheme, it would be eligible for consideration. There's obviously some gray area there for case-by-case evaluation and the question of when things took place becomes relevant, but I hope this sheds a bit more light both on GBCI's reasoning around the issue and my unhelpful response.
I think we'll just replace your photo with a grain of salt, Dan.
our project does sub-meter water for irrigation. However, the facility manager uses this water also for watering greenery which is outside of LEED boundary (greenery owned by the city) thus the water consumption is much higher than it would be according OPTION 2 (I would use only greenery on the project site for the calculation).
We want to install a water tank to retain rain water. Is it possible to go for OPTION 2 instead of OPTION 1 even though we are sub-metering water for irrigation?
Thank you for any suggestions.
Jiri, you can choose whichever of the three credit options is most suitable for the project.
Our project site is in an urban location with a small landscaped area (about 4%). LEEDUser specifies that there is a 5% minimum area requirement whether it is landscaped area or planters/rooftop garden. However, it seems to me that the reference guide and credit form only require 5% area if the "project conditions do not allow for installation of vegetation on the grounds." Can you clarify this?
It sounds like your project may not be eligible to pursue the credit. Vegetated space equal to at least 5% of the total site area is required, regardless of the project location or constraints.
Hi we are attempting this credit for one of our existing schools project.The project does not have permanent irrigation system.The landscape areaThe landscape area is the total site area less the building footprint, paved surfaces, water bodies, and patios. is irrigated manually by the facility staff members.Also as it is a school facility so the natural turf has been replaced with the artificial turf in the soccer field which does not require any irrigation. Will this help in getting all the 5 points for the project.Please suggest.
Kevin, the credit is about reducing 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. use, so manual irrigation is not a way to earn the credit. In fact, manual irrigation can be less efficient than some permanent systems.
The artificial turf won't help you earn the credit, because LEED does not want to incentivize reducing landscaped area as a way to earn the credit. The baseline and actual case here use the same landscaped area.
I agree with Tristan on everything above, although I do pause at the artificial turf issue. Certainly LEED would not want to provide an incentive for replacing landscaped area with say, a concrete patio or parking (thereby reducing irrigated area). But the use of artificial turf is effectively a zero-water method of providing nearly the exact same functionality. Here in Northern California artificial turf fields are becoming more and more common and the water savings are substantial. I'm not entirely convinced that LEED shouldn't support the switch from grass to artificial turf in WEc3. I suspect Tristan is right as to how a reviewer will respond, but its an interesting one for debate.
Hi Tristan and Dan, how are you?
Your knowledge from Leeduser always is very useful in my projects.
What if I have the following situation: The lanscape area of an office building is irrigated manually only with reuse water (no potable). It's not economic feasible apply an irrigation system. Can this credit WEc3 be atempted? Thanks!
Hi, I am working on a LEED project. My performance period is from April to July, 2012. During that time, I am also working on the reclaim water project which is used for cooling tower make-up and irrigation. The design stage has been finished and now we are under construction. The project is expected to be completed by end of 2012. Before that, we are still using portable water for irrigation & cooling tower. Is there any way that my ongoing project will be counted for the credit? Thanks in advance.
Hi Linh, I'm no review expert, but I don't see how this would fly since during the performance period you need to demonstrate that the strategy is in place. In this credit specifically you must show 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. use and reclaim or reuse water use % and back it up with meter readings in order to achieve. Hope this helps!
We performed a full audit of the irrigation system and some of the findings were to turn off zones that are watering established plants or mulch areas. This creates a lot of savings in real life, but it is not metered so we can't show exactly where the savings are.
Can we reflect this in the table, or are the reviewers going to say that a zone not irrigated in the design case must be shown as not irrigated in baseline case. It seems unfortunate that the fake LEED baseline does not reflect reality.
should we submit an alternative compliance path?
My take on this is its an example of a situation where its important not to let the LOL template divert you from describing the situation in the most intuitive and clear manner. I think GBCI agrees that shifting turf grass to xeriscapingXeriscaping is a landscaping method that makes routine irrigation unnecessary. It uses drought-adaptable and low-water plants as well as soil amendments such as compost and mulches to reduce evaporation., for example, is an irrigation water use savings that should be reflected in this credit even if it technically means you have reduced the irrigated area at hand. Your situation is no different. I would consider taking two steps: 1. In the template, keep your irrigated area consistent between the baseline and design cases, but account for the water used to irrigate that specific zone as 0 (or some diminishingly small number like 0.001 to make the template work). 2. Use the special circumstances box to explain exactly what you've done and how you've done it. Make it transparent to the reviewer so they can follow your logic and the template work-around. That way, even if they prefer you document your savings in a different manner, they will understand your intent and achievements fully.
I am trying to determine the conventional irrigation system rate for my region (option 1, choice 2) in order to compute a typical baseline. I've talked to local irrigation installers, a landscape architect, the state extension office, and multiple facility managers and no one quite knows what LEED is asking for here. The equation expresses the term in gal/sf/in which is what confuses everyone. All express typical rates for the region in gpm. Any other ideas/examples on how to derive this variable?
I believe that term in the reference guide has a typo and is meant to be gal/sf/min. The value that you ultimately need is the gallons of water used over performance period for a conventional system. That value, for the baseline case, is a function of the gallons per minute applied to a given area, like 1 gallon per minute per square foot while the irrigation system is running. From there, take the total amount of time the irrigation system is expected to run over the performance period and your total irrigated site area multiplied by the rate (gal/sf/min) to determine the baseline water applied.
According to the glossary of the refernce guide, the 'landscape areaThe landscape area is the total site area less the building footprint, paved surfaces, water bodies, and patios.' is the the total site area less the building footprintBuilding footprint is the area on a project site used by the building structure, defined by the perimeter of the building plan. Parking lots, parking garages, landscapes, and other nonbuilding facilities are not included in the building footprint., paved surfaces, water bodies and patios. Consequently roof gardens would not be included. Can I include roof gardens in my calculations for irrigation, if a part of my roofgarden is irrigated? (Do I have to include it or can I include it?)
Yes, I interpret the rating system language to imply that roof gardens have to be included. Also the total vegetated area needs to equal at least 5% of the building site area to be eligible for the credit.
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In addition to reducing potable water consumption for irrigation, rainwater harvesting can be used to manage stormwater runoff and can contribute to WEc3.
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