Reeds have been used in water remediation for many years. Reeds are used because they thrive in waterlogged conditions, surviving in up to 12" of water. Reeds also have extensive root structures and it's these structures that are an integral part of the filtration process within a reedbed remediation system.
Within the reedbeds of the Coal Authority's mine water treatment schemes there are generally three types of reed/rush as described below.
Phragmites Australis
Phragmites Australis:
Characterised by its towering height of up to three metres and its stiff wide leaves and hollow stem.
Vegetative spread by below-ground rhizomes can result in dense colonies with up to 200 stems/m².
Typha Latifolia
Typha Latifolia:
The common English 'bulrush'. This robust species grows up to 2.5 m in height, and has linear leaves. The most characteristic feature of this plant, is the distinctive, dark brown busby-like flowering head, known as a 'spadix'.
Yellow Flag Iris
Yellow Flag Iris:
The flower is made of 6 yellow petals that spread out 2-4 inches wide. The flower stalk rises out of the reedbed reaching heights up to 3 feet tall. The leaves are long and sword-like often reaching lengths of 32 inches.
These plants are generally used around the exterior of the reedbeds as a decorative plant which gives a softer appearance to the edges of the reedbeds.