Host or attend a workshop? Get in touch — email info@fictilis.com

What's that thing in the water?

It's a raft growing plants that help clean water — a Floating Treatment Wetland.

Modular Floating Treatment Wetland prototypes — hexagonal and square rafts with young plants — floating on an oxbow pond surrounded by trees.
prototype at deurendis, Northern Catskills 2026

The workshop

DeJoux House

Wallkill Futures · New Paltz

A hands-on design/build session at DeJoux House — participants assembled modular rafts from local biomaterials and planted willow and sedge for oxbow installation.

Nyquist-Harcourt Wildlife Sanctuary

Oxbow ponds · Huguenot St entrance

Prototype build and install in sanctuary oxbow ponds with Wallkill Valley Land Trust stewards and New Paltz neighbors — covering materials, plant species, water testing, and site care.

Get in touch

Upcoming

Bring a hands-on Floating Treatment Wetland session to your watershed group, school, land trust, or community — we’ll tailor materials, scale, and site to the water you steward.

Get in touch

Part of Wallkill Futures at Unison Arts, opening July 2026.

What is a Floating Treatment Wetland?

Suspended above the deepest part of the oxbow and anchored to bottom and shore, it can adjust to fluctuating water levels and flows. Below the surface, the roots develop a biofilm of bacteria and fungi that help absorb nutrients like nitrogen and phosphorus that can feed harmful algae, as well as heavy metals and other potential contaminants. In fall, the biomass is harvested and reused for other ecological projects, as part of a low-maintenance system that supports the health of the Wallkill River and watershed. These modular prototypes were designed by FICTILIS using locally abundant biomaterials, and installed as a research project in partnership with Wallkill Valley Land Trust and with permission from adjacent property owners.

How it works

Floating Treatment Wetlands are small, raft-like buoyant structures that mitigate nutrient and chemical pollution through root and microbial uptake — reducing algae and harmful bacteria, turning nutrients into usable, sequestrable biomass, and providing wildlife habitat and a self-watering growing medium for native sedges, willow, and other species used in riparian restoration.

Why here: the Wallkill

The Wallkill has no single big polluter. Instead it suffers a death by a thousand cuts — arsenic leaching from natural mineral deposits, stormwater carrying nutrients, salts, and pesticides off streets and farms, leaking septic and sewage adding bacterial contamination, and climate change plus excess nutrients fueling toxic algae blooms.

Drawn from Bard Center for Environmental Policy (CEP) material.

Our research + design

We're studying locally sourced, low-cost designs for scalable Floating Treatment Wetlands — for harmful-algae-bloom prevention, stormwater and wastewater pollution, pre- and post-treatment of agricultural irrigation and runoff, and other remediation of rural and urban waters. Our prototypes use abundant local biomaterials, including pontoons made from harvested Japanese knotweed, and draw on ancient Meso-American floating-garden methods — re-cultivating a local aquacultural tradition. Each fall the growth is harvested and put back to work in riparian planting elsewhere.

  • Close-up of willow rods sprouting green leaves through burlap on a floating raft frame.
    willow rod — detail
  • Square floating raft with willow cuttings in a grid, knotweed stalk frame visible at edges.
    knotweed cane pontoons · prototype frame
  • sedge plugs — detail · documentation in progress
  • Hexagonal raft prototype from above showing white mesh netting over coir substrate and planting ports.
    netting · hexagonal prototype
  • Cluster of circular coir rafts lashed together with woody knotweed pontoons beneath.
    lashings · coir ring modules
  • water sample — detail · documentation in progress

The lineage / background

For as long as people have lived in this valley, some of them have lived at its edges — in the swampy lowlands no one else wanted. Near Kingston they were called the Binnewaters, or "Eaglenesters"; across the river, the Taghkanic basketmakers. They were people of Lenape, African, and Dutch descent whose origins got deliberately blurred by the people around them, and who lived on what the wet margins gave them: fish, foraged food, and baskets woven from willow and splint cut at the water's edge. For it they were slurred, studied as if they were defective stock, and written off as a vanishing kind. They didn't vanish. They kept weaving, and kept their footing in the low wet places, generation after generation. When we gather to build floating wetlands out of local willow, we're working in that long tradition — people at the margins, making something useful with the plants of the marsh, together.

Sources / further reading

  • Hurley Mountain Stories (NEH-funded, CC BY-NC) — "To Live Deliberately: From Walden Pond to Eagle's Nest Road," by Lorna Smedman.
  • New York Times, 1897 — "Strange Colony in Ulster."
  • Croswell Bowen, Great River of the Mountains (1941).
  • Martha Wetherbee & Nathan Taylor, Legend of the Bushwhacker Basket (Taghkanic basketmakers).
  • Richard de Lisser, Picturesque Ulster (1890s).
  • Elise Lemire, Black Walden (2009).