In the area you have selected (San Diego) river flood hazard is classified as very low based on modeled flood information currently available to this tool. This means that there is a chance of less than 1% that potentially damaging and life-threatening river floods occur in the coming 10 years (return period of c. 1 in 1000 years). Therefore, based on this information, flood hazard does not need to be explicitly considered for your project. Surface flood hazard in urban and rural areas is not included in this hazard classification, and may also be possible in this location. Please see 'Urban Flood' for consideration of urban surface and river flooding.Although the hazard is considered to be very low or non-existent in the project location based on the information available in ThinkHazard!, additional information may show some level of hazard. If local or additional information sources suggest that there is flood hazard, follow the recommendations below and seek expert guidance on additional recommended actions. It is recommended that local flood regulations and conditions possibly leading to highly localized water nuisance problems are considered. In particular, it is recommended to check the condition of and possible flaws in local water management systems, e.g. poorly dimensioned or maintained sewerage or drainage channels. Always consider taking no-regret measures.
Climate change impacts: In western, central and eastern continental US, medium confidence in an increase in the number of extreme rainfall events. In northeast US, medium confidence in an increase in days of intense precipitation. In southeastern US, model projections are inconsistent in changes in rainfall. In Alaska, high confidence in an increase in days of intense precipitation and the number of extreme rainfall events. The present hazard level may increase in the future due to the effects of climate change. It would be prudent to design projects in this area to be robust to river flood hazard in the long-term.
For further information the following resources could be consulted: