The increasing volume of municipal solid waste (MSW), including biodegradable plant residues such as pruning, leaf, and kitchen wastes, presents a substantial environmental challenge due to the limited availability of landfill space and the resulting environmental contamination. Sustainable waste management practices, encompassing recycling and waste-to-energy conversion through biological or thermochemical processes, are imperative. In the Municipality of Athens, Greece, significant quantities of green waste generated from public and private gardening activities provide a valuable opportunity for energy recovery and landfill waste reduction. In accordance with Directive 2008/98/EC, Athens emphasizes waste prevention, reuse, recycling, and recovery. This study examined alternative bio-waste and green waste management systems, using examples from Europe, focusing on the Athens Directorate of Urban Green Spaces and Urban Wildlife. This paper discusses methods for assessing the energy value of pruning residues, providing a definitive disposal framework. Additionally, it presents a technoeconomic study of one of the municipal swimming pools in the Municipality of Athens, investigating the production and distribution of thermal energy to meet the heating needs of the pool facilities. This research identified key constraints and their impact on decision-making, highlighting the potential for alternative green waste management strategies. It advocates modern recycling techniques in line with national and community legislation, which have significant environmental and economic benefits.