For this smart garden, no worries when it rains and rains

New York's smartest garden makes sure none of its water goes to waste.

Alfred Ng Senior Reporter / CNET News
Alfred Ng was a senior reporter for CNET News. He was raised in Brooklyn and previously worked on the New York Daily News's social media and breaking news teams.
Alfred Ng
4 min read

The Brooklyn Botanic Garden's Water Garden is hooked up to the cloud to take on the rain.

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In New York, the Brooklyn Botanic Garden is using the cloud to handle too much rain.

When Superstorm Sandy dumped more than 7 inches of rain across the east coast in 2012, New York got hit hard. The city sustained up to $19 billion in damages and saw 5 billion gallons of sewage overflow.

Those volumes worried the staff of the Brooklyn Botanic Garden, which had been planning a Water Garden with a pool that doubles as storage for rainwater but feared another overflow. As a result, the mixture of excrement, rainwater and sewage streaming into New York's waterway played a part in the city's first "smart garden."

The garden relies on an automated system called OptiNimbus that uses an algorithm to track rainfall and adjusts its water levels accordingly.

"We're discharging in advance of rain so we're not putting water through the sewer system," said Scott Simpson, the project manager for Opti, the Boston-based company that created OptiNimbus.

The Brooklyn Botanic Garden is just the latest public venue to embrace tech to run more efficiently or offer more services. From the California Academy of Science's Living Roof, which helps control the museum with weather stations, to the 49ers' high tech stadium and even whole cities like Amsterdam, many are embracing the idea of connecting their infrastructure to the internet or letting more bits of code handle their operations.

In order to smarten up its system, the Brooklyn Botanic Garden worked with Opti and the designers at Michael Van Valkenburgh Associates to dry their water worries.

"The garden-wide Water Conservation Project -- taking place underground -- is every bit as remarkable, with a water management system that will be a model for other institutions and civic organizations," Scot Medbury, the garden's president, said in a statement.

Watch this: At Brooklyn smart garden, when it rains, it drains

Storm tracker

Opti created the OptiNimbus program in 2007 to handle water flow in a salt marsh using a web server on the valve's controls. Since then, it's expanded to connecting water systems to the cloud from Washington, DC to Oregon.

For the Brooklyn Botanic Garden, OptiNimbus grabs data from the National Weather Service and the National Oceanic and Atmospheric Administration's forecasts and pairs it with an algorithm to automatically determine if it should drain the pond based on how much rain it expects to come. It recalculates the weather forecast once a minute. With the valve connected online and managed through a web dashboard, staffers at the Brooklyn Botanic Garden can control it from devices anywhere.

That means if it's expected to rain three inches on any given day, the valves underneath the Water Garden could automatically release the same amount of water from its pond, keeping the water levels steady after the downpour.

By doing this, the Water Garden doesn't overflow from the rainfall, preventing excess water from splashing toward the storm drain and combining with the sewage.

OptiNimbus also talks with a water level sensor under the pond through a cellular connection for real-time data.

The pond can rise up to three feet before the system decides water should be released prior to rainfall.

Getting it right

The algorithm has already made the right call in cases where people would have trouble deciding. When New York expected flooding and heavy rain on January 23, conventional wisdom might have been to drain the pond in anticipation of the heavy influx of water expected.

The day before the storm, the pond's water levels had been pretty low, and OptiNimbus opted not to drain. It was the right decision.

"Sometimes we would watch a storm come in and we'd say, 'I think we should release water.' But the algorithm would say 'no, don't do it,'" said David Roman, a water resources engineer at Geosyntec, a consulting firm that worked on the garden. "It was really cool how often it was right."

No water has been discharged from the Brooklyn Botanic Garden's Water Garden since the system went live.

After enough situations, the algorithm is expected to learn enough to run entirely on its own. OptiNimbus reviews its systems every few days and analyzes its decisions, Simpson said.

The first phase of the project was unveiled when the Brooklyn Botanic Garden opened the Water Garden to the public last September. It's expected to be completed by 2018, when the pond's water can be recirculated and used in its Japanese Garden pond.


The water will be recirculated to the Japanese Pond garden, helping save millions of gallons of water.

Alfred Ng/CNET

Completing the next phase would mean the garden could stop relying on 22 million gallons a year for the Japanese pond, dropping down to only 900,000 gallons annually.

But it wouldn't be a garden without some floral life. Unlike Opti's other projects, which are basic storage systems or rainwater-harvesting tools, the Brooklyn Botanic Garden disguised its stormwater management as a lake surrounded with nature that adapts with the adjusting water levels. They're described as riparian, or "wet-feet" plants, including rhubarbs, perennials and the cardinal flower.

These plants, which are used to being at the water's edge, thrive in changing water levels.

"The goal of the garden is not to be a piece of infrastructure," Roman said. "It allowed us to create something that was unique and meet the engineering goals and without hitting people over the head with it."

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