In the paper I propose a decision opportunity for the problem of basement flooding caused by heavy precipitation: property owners can mitigate this risk before it materializes. Implementing the decision opportunity requires an active choice. Social science findings suggest comprehensive and pervasive information processing deficiencies together with contextual influences strongly affect decision behavior. Presenting the decision opportunity in a way that limits negative interference from these behavioral problems is therefore a key theme of the paper. I adopt the PrOACT approach to analyze and resolve these distinct problems. This involves exploring relevant objectives for property owners and for the presentation of the decision opportunity. I consider several technical as well as behavioral alternatives. Backwater valves represent the main group of the former and choice architectural tool sets the latter. Backwater valves block sewage backflow while choice architecture concerns how to present a choice given behavioral problems. By considering the consequences of these alternatives on the relevant objectives the process of eliminating dominated alternatives is pursued, followed by making tradeoffs which enable the identification of suggested choices. Subsequently, I propose that the mechanical backwater valve is preferable for implementing the decision opportunity. This alternative scored well on providing protection, being relatively cheap and involved few additional inconveniences relative to doing nothing about the risk. For presenting the decision opportunity the paper suggests the choice architectural tool set of customization and technology. This alternative scored well on promoting an active choice, promoting welfare increasing choices and providing guidance to property owners. However, its shortcoming is found in its limited capacity to reach all relevant property owners. The paper identifies a need for experimental evidence on the effects of these suggested measures. The starting point for such experimental explorations is further proposed to originate from the paper’s suggested choices.