1) The Witham Leas are one of 13 sites consisting of wetland, representing 7% of Lincoln's wetland resource. There are patches of willow scrub and secondary woodland at the northern end of the site (area unknown). There is an area of amenity grassland on the east side of the site.

2) The site provides breeding habitat for a number of aquatic birds including great crested grebe, little grebe, mute swan, mallard, tufted duck, reed warbler and reed bunting. The sheltered nature of the site in an otherwise well populated area supports the breeding species above, some of which are uncommon residents in an urban context.     

3) The site is an important component in a complex of SNCIs along the Witham Valley, an important wildlife corridor. Along with Boultham Park SNCI, Witham Leas SNCI has an area of woodland and scrub, and therefore provides important habitat diversity in an area otherwise dominated by rough grassland and wetland.