What additional feature must subdivision plans address for potential flood impact?

Subdivision plans must specifically address flood level determination to effectively mitigate potential flood impacts. This feature is crucial because understanding the flood levels helps in planning the layout of the subdivision, ensuring that homes, critical infrastructure, and public spaces are situated above the highest expected flood levels. This proactive approach reduces vulnerability to flooding, enhances safety for residents, and can potentially lower flood insurance costs.

In addition, determining flood levels enables planners to implement adequate drainage systems, retention basins, and other flood control measures that are necessary for long-term sustainability and protection of the community. It ensures that codes and regulations around construction elevation are met, which can be vital for compliance with local and federal floodplain management regulations.

The other options, while relevant in the broader context of community planning, do not specifically address the immediate and critical concern of flood impacts as effectively as flood level determination. Proximity to emergency services, presence of wildlife habitats, and documenting historical flood events all provide important context but do not directly influence the foundational design and safety features of subdivision plans regarding flood management.