Perhaps the greatest obstacle that confronts the implementation of commercial-scale hydrokinetic devices in rivers is debris. Until recently, this problem has been largely avoided by installing devices in areas where debris is not a factor. This practice significantly limits the possible locations for deployment, however, so new techniques must be developed. Although there is little precedent for large hydrokinetic devices and the issue of debris, there are examples of efforts to protect other engineered riverine structures. In addition to presenting these examples, we discuss the mechanisms for how debris enters the flow and is transported downstream, as this information can provide important in sight in the development of debris mitigation strategies.