This project in St Albans was to bring the river and lake back to life and incorporated six diverse river reaches. Our work to date has included a feasibility study, optioneering, selection of a referred option and outline design.
The river was in poor condition and the lake was considered eutrophic as a result of poor water quality, siltation and excessive numbers of wild fowl. Algal blooms and reduced oxygen levels in the water had impacted on wildlife.
Throughout the project we worked closely with the client as well as a project steering group that included Affinity Water, and the local council and wildlife trust. We developed more than 50 management and restoration options with benefits to heritage, utilities, hydrology and flood risk, geomorphology, habitat creation, water quality, landscape, amenity, fish passage and sustainability. Fifteen were shortlisted and considered in further detail. Additional studies were then undertaken and reviewed to determine the preferred option for each reach.
The preferred river options included improvements, such as the creation of in-channel berms and riffles, wetlands and wet woodlands. They also featured channel re-alignment to the natural valley bottom, the river being reconnected to the floodplain, and significant access improvements that would enable locals to engage with the river. Lake improvement measures were also developed including improving the flow through the lake, partial infilling and the creation of wetland areas.
We worked closely with the project steering group to ensure public understanding and buy-in.
The proposals were accepted and went on to detailed design and implementation.