You may have noticed something new in the water at Rockland Lake State Park. These are floating treatment wetlands! Read our post below to find out more about these water treatment platforms.
Why are they here?
In recent years, harmful algal blooms have become common in Rockland Lake. These algae blooms are largely caused by an unhealthy increase in nutrients such as phosphorous in the lake. The nutrients come from many sources nearby, including excess lawn/garden fertilizers that wash into storm ditches after a rainfall, then drain into Rockland Lake. One culvert (inlet) with consistently high nutrient levels is located near Parking Field 5 and it was chosen as the location for a new floating treatment wetland. The goal of adding a floating wetland to the lake is to reduce the amount of nutrients – and by extension, harmful algal blooms – in the lake.
What are they?
Floating treatment wetlands (a.k.a. floating wetlands/islands) help to bring the benefits of natural wetlands to polluted water. They filter water to improve water quality and they provide important habitat for a variety of plants and animals. Floating wetlands can come in different shapes and sizes, but in general, wetland plants are supported atop a buoyant platform, with roots exposed in the lake water below.
What do they do?
Floating treatment wetlands help to create the right balance of submerged and non-submerged wetland habitat based on each individual site’s needs. As the plants grow, they use-up excess nutrients in the water. In addition, communities of beneficial bacteria form a film around the roots, further helping to filter nutrients and pollutants. Higher/lower elevations create areas with varying oxygen levels, promoting these different biological filtering methods. The floating platform blocks sunlight, preventing the growth of algae. Lastly, fish and wildlife enjoy the new addition to their habitat.
Floating wetland materials arrive by truck in late July 2017, photo by State Parks
More floating wetland materials. Plants from a local nursery include: tussock sedge (Carex stricta), swamp rosemallow (Hibiscus moscheutos), Blueflag iris (Iris versicolor), and soft rush (Juncus effuses), photo by State Parks
Floating wetland materials. These special polyester supports will help hold the plants in-place for years to come., photo by State Parks
Constructing the floating wetland! Some of the plants are submerged, while others are elevated on an island., photo by State Parks
One of several floating wetland units., photo by State Parks
Constructing the floating wetland! Units are assembled near the shore, to be later brought to the target location., photo by State Parks.
Another close-up, with thin netting around the edge to protect the young plants from birds., photo by State Parks.
Close-up of a floating wetland unit. Brick weights help keep the plants evenly balanced, with roots below water, photo by State Parks.
Floating wetland at Parking Field 5 culvert, September 2017, photo by State Parks.
Finished floating wetland, installed at Parking Field 5 culvert. The green “spilled paint” look on the water is a harmful algal bloom. Photo from early August 2017, photo by State Parks.
This is the first time that floating treatment wetlands have been used in New York State Parks. Environmental staff will determine the effectiveness of this project by monitoring water quality changes over time (e.g. harmful nutrient levels and algal blooms by the inlet as well as lake-wide). If successful, then floating wetlands may be used to help treat stormwater pollution and improve other aquatic habitats in New York.
Post by April Brun, Gabriella Cebada Mora, and Erin Lennon.
Rockland photos by Gabriella Cebada Mora, Aissa Feldmann, Matt Brincka, and Erin Lennon.
Rockland Lake, a 256-acre spring-fed lake at the foot of Hook Mountain, is today one of the most popular state parks in the Hudson Valley. Its two golf courses, pool, tennis courts, hiking trails, and ball fields attract legions of people in the summer months, who come to fish, picnic and play in this park along the Hudson River. And while few people know that the lake once (still might?) claimed to be the home of the world’s largest snapping turtle, there is a growing number of people who proudly point to Rockland Lake’s massive stone ruins along its eastern shore as laying claim to global fame on a distinctly different level, one that is very, very cool.
In 1806, up in Boston, a young and enterprising man named Frederick Tudor cut chunks of ice out of his family’s pond, loaded it onto a boat, and set sail for Martinique, convinced that the world would soon have an insatiable desire for ice in their drinks. He was a man ahead of his time, and after many false starts, bankruptcies, and even debtor’s prison, his idea finally caught on, and the demand for ice to cool drinks and preserve food spread around the globe. Rockland Lake, because of its clean spring fed water and proximity to the Hudson River, New York City, and international shipping lanes, soon became the undisputed leader in this new and sustainable industry, and the Knickerbocker Ice Company was formed in 1831 to meet that demand. What began as a single warehouse to store the ice blocks neatly cut into 20” x 40” rectangles soon became three massive structures capable of containing over 100,000 tons of ice.
A railway was built to convey the ice over Hook Mountain, and included a gravity-fed incline took the cars down the steep face of the mountain to a massive pier, where ice barges on the river were filled and shipped to the city. New York’s “Meat Packing District” was located on the Lower West Side to take advantage of the ice shipped down the Hudson on these barges to cool the meat. Soon, the ice from Rockland Lake became so famous around the world that imitators sprung up, and even a lake in Sweden was renamed Rockland Lake so that its owners could claim that they sold “Rockland Lake” ice. It’s hard to imagine that blocks of ice were shipped from a rural New York lake to exotic destinations like Australia and Asia, but for many people and businesses no other ice was as clear and clean as Rockland Lake Ice.
The ice at Rockland Lake was so famous that, in 1900 Thomas Edison Films documented the entire process of harvesting the ice at Rockland Lake, from the horses drawing the ice plows to the workers loading it onto the barges. Watching that film, it is hard to imagine that today the same site is far from the industrial zone depicted in the grainy black and white film.
By the early 20th Century, however, technology had caught up with demand, and artificial ice began to displace naturally harvested ice for most purposes, and while natural ice harvesting continued (and continues today) to be a sustainable source for cooling elsewhere, the harvests stopped at Rockland Lake in 1924. In 1926, while demolishing the facilities to make way for what eventually became summer cabins and hotels, a fire broke out in one of the buildings whose huge double-sided walls were packed with tons of sawdust to keep the ice cool. When the smoldering fires were finally extinguished (anecdotally, some said that they burned for over a year), all that was left of the houses were the massive stone walls at the base of Hook Mountain. Eventually, in the 1950s, the Palisades Interstate Park Commission began buying up private parcels, and in 1965 Rockland Lake State Park welcomed its first guests. The ruins of the ice house remained, lost but not forgotten.
In 1988, park manager Jack Driver and his wife Barbara led tours of the ruins to those curious about their history and Barbara led volunteers in the successful effort to have the ruins designated as an official Clarkstown Historic Site. While they managed some success, the Drivers moved to another park assignment away from Rockland Lake, and no proper dedication had ever taken place. Twenty years later, after jogging past the ruins countless times on the lake’s three-mile paved path, Rockland resident Timothy Englert inquired about the walls, which now contained a tangle of black locust and other trees. John Burley and Mike Krish, park managers, handed Mr. Englert a manila folder, inside of which was a trove of information regarding the history of the lake’s icy past, as well as official-looking documents attesting to its historic status. The forgotten folder also contained a faded black and white panoramic photograph of the ice harvesters standing atop the frozen lake, a photo that evoked the pride of place and industry that employed thousands of people during a period of great growth.
Mr. Englert realized that no dedication had ever taken place. He enlisted the help of Robert Patalano, a fellow Clarkstown resident and professional ice sculptor, who sculpted an 18’ ice replica of the original Knickerbocker Ice house, while Mr. Englert took one of the rot-resistant locust logs and created the Knickerbocker Bench to commemorate the site with something a bit more durable than ice. On a bitter cold weekend in January of 2007, the Driver family returned to Rockland Lake as the guests of honor at the Knickerbocker Ice Festival, which grew from a few hundred people that first year to over 25,000 people two short years later. The festival included massive ice sculptures and historic tours. That first sculpture lasted five weeks before it melted away.
Today, the legacy of ice at Rockland Lake lives on in historic markers placed throughout the ice house ruins at the park. Rockland Lake isn’t the only State Park where ice was once harvested. Both Bear Mountain and Schodack Island once also had ice houses of their own. And while the ice festival is no longer an annual event, the spirit of the ice lives on in the Knickerbocker benches found along the park’s trails, and in the pride of Rocklanders, who can walk into the ruins of Ice House #3 on a hot summer day and imagine themselves surrounded by 100,000 tons of ice.
The Knickerbocker Bench was created by artist Timothy Englert to pay tribute to the Knickerbocker Ice Houses at Rockland Lake, photo by Timothy Englert
Ice version The Knickerbocker Bench was created by artist Timothy Englert to pay tribute to the Knickerbocker Ice Houses at Rockland Lake, photo by Timothy Englert