After excavating the pond and creating banks, in early 2016, the pond was filled, but failed to retain water, despite high clay levels in the substrate. Volunteers tried clay puddling and bentonite layering, but these were not effective. Finally, in spring 2017 a custom-made butyl membrane sandwiched between protective geotex layers was installed – with a soil layer on top, and the pond no longer leaked. Coir rolls and mats pre-planted with native British pond plants and marginals, and deeper pond plants like water lilies, were introduced later in that spring, and the pond now has a very established look.