CS 2009 WEc1: Water Efficient Landscaping

Adam, let's separate the LEED and the plumbing code issues—I'm not exactly sure which you are asking about.

From a code perspective, any possibility of untreated rainwater coming out of a 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. fixture will need to be avoided. So depending on what you mean by connecting the systems, that could be an issue. That is what the sentence you're quoting is about.

From a LEED perspective, I don't see an obstacle to compliance, since the credit requirements are based on calculations, not precise system design. You should, however, ensure that your catchment tank is of an adequate size that you can capture enough water to irrigate according to what you promise in your documentation.

Aha then I understood the statement that I quoted in a wrong way. I thought that from a LEED perspective it is not allowed to have a rainwater tank connected to a 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. system in order to fill it in in case there are no rains for a long time. In this situation there would be a potable water used for filling the tank and for watering the plants. But this would happen only in extreme situations. Thank you for clarification.

Speaking to the question of whether LEED will accept a 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. connection to rainwater collection: A couple years ago we did a project that was collecting rainwater for reuse in an open pond, and we were denied this credit because there was a municipal water connection to the pond. This was despite the fact that our calculations showed the potable water would never be needed under typical rainfall conditions.

We submitted a statement from the landscape designer along with pictures of the temporal irrigation (small trucks with water tanks) during the plant establishment. That was sufficient for the reviewers.

Thank you Susan. Very usefull your answer!

We are planning our landscaping with native/adapted plants and we are not going to install permanent irrigation. During dry times of the summer, we may want to handwater plants using small trucks with water tanks to keep the landscaping from going brown. Is this acceptable if we want to achieve all 4 points on this credit?

No 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 or no (long term) irrigation for a possible 4 points still require you to show the planting layout/pallete that proves you are taking advantage of native/drought tolerant plants, and are actually doing a real landscaping less the water. If you are manually watering the plants (actually planted in the soil), I guess you need to provide a schedule (name of person and his schedule). Seriously, achieving the 4 points should reflect the sustainability of the design level you are trying to achieve.

Steve, what we have heard from projects is that leaving lines in place is okay, but that the system must be disabled in some way so that there would need to be a clear, nontrivial, intention to reactivate it down the road. Removing the sprinkler heads seems to be a common way of achieving this. I'm not sure whether or not removing an automated control would quite reach that threshold, but I can't picture your project specifics.

The baseline case is supposed to represent conventional landscaping choices for the region, according to the LEED Reference Guide.

A non-native plant could be part of the baseline if it's conventionally used there in landscaping.

We have a project that is a zero lot line and because of the shape of the building it will be impossible to have a greenroof.

However there could be some vegetation inside the building that since the lower lever will be retail.

Can this type of vegetation be considered so we can comply with the WEC1?

David, read about planters in the question just above this one, and in the Checklists tab.

I'm not an expert on LEED-CS 2.0, but I would assume it's the same as NC. As we discuss in some more detail above under Checklists, you have to have some landscaping to be eligible for the credit. Planters can be landscaping.

Part of the idea here is to not incentivize projects to earn the credit
by paving over everything or installing artificial turf, ec.

Thanks Tristan for your feedback. It was my understanding that to meet the credit it would be expected that some landscaping is required too.

Just wanted to share with other forum users that in the latest version of the LEED Manual, LEED BD&C 2009 Reference Guide p182-183, it is noted that for WEc1 the landscaping would need to be a minimum of 5% of the plot area;

"For buildings without vegetation on the grounds, teams can earn points by reducing 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. for watering any roof and courtyard garden space or outdoor planters, provided the planters and 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., hardscape area, parking footprint, etc.). If the planters and garden space cover less than 5% of the building site area, the project is ineligible for this credit."

Even in a case where 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. is used, you still have to reduced your "total water applied" by at least 50%, which will require the basic baseline calculations that are standard for this credit. These calculations are discussed in more detail in the Getting It Done tab, above.