Evaluation of the Ecosystem Services and multiple benefits provided by SUDS and non SUDS ponds

Abstract

This thesis explored the potential of four Sustainable Urban Drainage (SUDS) ponds, and four non-SUDS pond, to deliver key Ecosystem benefits, and services. Sustainable Urban Drainage Systems are designed to improve water quality, and provide amenity, biodiversity, and flood alleviation benefits. Ecosystem Services (ES) refer to the end user benefits associated with an ecosystem, and which are of direct use for humans. Within the context of this study, the key Ecosystem Service (ES) is water quality regulation which was considered using the proxies of macroinvertebrates and diatoms. An additional Ecosystem Service is wild species diversity which involved monitoring and evaluating flowering plants in relation to pollination. The project had four main research questions (RQ), and each was supported by its own research methodology. First the effectiveness of water quality regulation in SUDS and non-SUDS ponds using Average Score per Taxon was monitored (RQ1); secondly, nutrient removal services was observed between pond inlets and outlets, and potential indicators for reference, disturbed, and toxicity (RQ 2) for the ES of water quality regulation. RQ3 considered the potential for ponds to support flowering plants suitable for pollinators for the ES of wild species diversity. RQ4 focussed on the public perception survey, and willingness to pay for the multiple benefits of ponds and evaluated these in relation to the Whole Life Cost of the pond. RQ1 revealed that median values were higher for SUDS ponds than non SUDS ponds but not of statistical significance (p>0.05). For RQ2, median diatom counts were not statistically significant between SUDS and non SUDS ponds (p>0.05). There was a statistical difference between median observations for plants suitable for insect pollinators (p<0.05) but not for wind pollination (p>0.05). RQ4 revealed that habitat provision benefits outweighed costs for SUDS and non SUDS ponds in relation to Whole Life Cost analysis. The proposed framework, resulting from this research, may be used to inform local decision making and policy for SUDS design. This research aids the understanding of valuing ponds in relation to ecosystem benefits and services. It also highlights the significance of incorporating disadvantages into economic assessment; particularly where direct comparisons are made between ponds.