Net Zero Water in Action

I was both honored and humbled to receive the Stormwater and Urban Watershed Development of the Year Award at the 2017 Iowa Water Conference on behalf of Indian Creek Nature Center.
What exactly, does net zero water mean, besides spending countless hours with a civil engineer on site design?

It means that the building and site were designed so that a) every drop of water that falls on the site, stays on the site, and b) throughout our operation, we use less water than falls on the site, over the course of the year.

A combination of native plantings (which don’t require watering), ponds, raingardens, and bioswales contain the water on-site. What was more difficult to predict was how much water we would consume, versus rainfall.

Four months into documentation, and we are doing well.

Month Water Used (gallons) Rainfall (inches) rainfall (gallons)  1 acre site
Dec-16 9,620.8 1.05 28,511.70
Jan-17 8,965.6 1.46 39,644.84
Feb-17 7,259.6 0.68 18,464.72
Mar-17 10,000.20 0.75 20,365.5

 

A stable foundation

A significant part of what goes into a sustainable building will never be seen after it is installed. People use the “good foundation” analogy a lot for everything from business practices to personal relationships. In terms of real structures…a good foundation starts with a trench.IMG_20150915_081423486

Ultimately, the building will stand on this spread footing. Ryan Construction reuses the wood for the footing on multiple projects, until it eventually disintegrates. All wood from this project that is damaged or cannot be reused will be recycled. As it is not green treated, it can be ground and used for mulch in a variety of applications.

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Throughout construction, independent inspectors will be verifying and testing everything. At this stage of the project, those inspections are verifying that the concrete is structurally sound and that the rebar is placed correctly.

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The foundation wallforms, laid out here and ready to be placed, are also reused on multiple projects. The orange toppers on the rebar protect workers from hurting themselves on the spikes.

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The pump truck, in the background, allows the concrete to efficiently be poured into the relatively narrow wall form, and minimizes spillage and waste.

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The foundation wall is done!

Lindsey and Andrea on the wall

Water on a Construction Site

Infrastructure in general, and parking lots in particular, are notorious for causing water problems. During a rain storm, a variety of factors coalesce to devastate local waterways. The rain water picks up contaminants, such as spilled oil and gasoline, and carries them into the environment, be it neighboring vegetation or rivers.

Rainwater is frequently channeled off of the surface through piping. This creates fast moving, focused torrents of water that erode the surrounding soil, carrying silt into the rivers and creeks. Cloudy water makes it impossible for some fish and other wildlife to live.

The Indian Creek Nature Center is taking a number of steps to decrease those problems on its new site. The goal is to keep 100 percent of any runoff on its own property-even during construction. Areas were excavated to temporarily hold any rainwater during the project. We had five inches of rain last week, and the dirty water stayed where it belonged.

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For the parking lot, the “net zero water” started with a complex underground design. The entire parking lot will be filled with large, clean rock that has significant void space. This allows a lot of water to stay directly under the parking lot, and the contaminants-whether its leaking oil or dirt from tires-to settle out before the water moves on.

IMG_20150915_082730459On top of the rock, the driveway will be concrete and the parking spaces will be permeable pavers that allow the water to drain down, not off. Below are the individual cells, or series of underground ponds that hold and slow the water, taking shape.

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Ultimately, any extra water will make its way into bioswales, where it will support native plants and can infiltrate back into the soil as clean, cool water.