This assignment falls aims to contribute to adaptation to flood risks by strengthening the resilience of infrastructure. It comprises a series of activities focusing on characterization and practical responses to the issue of surface runoff; including greywater; in the neighborhood of Balbala Ancien in Djibouti city.To better understand the scale but also the impact of the phenomenon on communities and infrastructure resilience; and propose concrete solutions; this TA will include a study to:(i) quantify and map the extent of surface standoff flows by determining their main source and pathway in Balbala Ancien; while providing a brief analysis of the current impact of surface standoff on the local environment; including on infrastructure resilience ;(ii) propose a benchmark of solutions for better management of surface standoff (in particular household grey water); on the one hand through preventive actions aimed at households (to reduce the scale of the phenomenon as much as possible); and on the other hand through the identification of innovative technical solutions adapted to the Djiboutian case; enabling better management/channeling of existing surface standoff;(iii) organize consultations with the concerned institutional stakeholders and with the population to fine-tune the results of the work to the specific context; institutional framework and local practices.