The island of Sacca San Matteo is simultaneously a stage of contradictory uncertainty and constancy. On one hand it is a site of potential flooding and domestic/visitor misuse, and, on the other hand, a field used for recreation and waste disposal. This park proposal re-imagines Sacca San Matteo as an exchange medium, operating between the scales of local Murano and the islands of the Venice Lagoon on an ecological, economic, and cultural level. The island is conceived as a constructed ground, organized along an open-ended series of operative ribbons that negotiate periodic flows, waste treatment, and human inhabitation. Some ribbons perform as living machines or a series of constructed wetlands that filter and remediate wastes produced by tourism and domestic use. Effluents from the wastes of tourists and local residents are unloaded onto the backdoor ( i.e. northeast end of the site) and are filtered and utilized for community agriculture distributed to the front door of the island (i.e. southern end). Prototypical growing barges that dock at the front door export agricultural products and species, potentially seeding and extending to other islands of the Venice Lagoon. Programs on the island shift and intersect the ribbons, taking into account varying degrees of necessity and ecological chance. Tourists and locals navigate between front door and back door, experiencing San Matteo’s cycles of waste to growth. “X-Change” takes a variable approach to the ground’s construction, allowing its ribbons to act as an armature for dynamic process and reciprocity between different pressures. Waste + food + People = X-Change