Riverside Gardens: creek and recirculation system. Aquatic and riparian vegetation

[Extract] The existing riparian and aquatic vegetation of the intermittent creeks which drain into the Ross River within the Riverside Gardens subdivision development are dependent upon seasonal flow to maintain conditions conducive to their establishment and growth. The development proposal intends to change the hydrology in these creeks such that semi-permanent flowing conditions will prevail, and to construct a small lake at the creek's confluence with the Ross River. The semi-permanent conditions will be maintained by pumping water from the Ross River to the "head" of each creek (at Angus Smith Drive) and then allowing for gravity feed back into the river. Concerns in relation to the health of the riparian and aquatic vegetation under these more regulated conditions have resulted in this study being commissioned. The vegetation of many watercourses in Australia have become degraded under a regulated flow regime, with trees which are not adapted to the changed hydrology either dying or becoming less resilient to environmental stresses (see below). This aims of this brief study are i) to assess the vegetation of the creek proposed to be modified, ii) to review the available literature on riparian vegetation and semi-permanent flows, iii) to provide recommendations for management of the riparian vegetation.