The reference state for ditches and drains on the Gwent Level would be that, at any given point in time, there would be a mix of recently cleared ditches, mature ditches with an advanced emergent and a good proportion of the ditches (perhaps 40-50%) in a state somewhere between the successionally-young and mature growth phases. Ideally, some 40-50% of the ditches would be more than 50% open water and support a species-rich aquatic flora. These more open ditches would be expected to support populations of the rarer aquatic plants in Wales such as lesser pondweed (Potamogeton pusillus), hairlike pondweed (Potamogeton trichoides), frog-bit (Hydrocharis morsus-ranae) and arrowhead (Sagittaria sagittifolia) – as shown in the image above.