Which two regulatory standards can encourage site designs that avoid building in floodplains?

The chosen answer highlights two significant regulatory standards that contribute to the encouragement of site designs, effectively steering development away from flood-prone areas. Subdivision design that promotes cluster development on higher ground allows for more intensive use of less vulnerable land while protecting floodplain areas, thereby minimizing the risk associated with flooding. This design strategy consolidates homes and buildings into smaller lots, thus preserving natural spaces and reducing the overall footprint in flood-prone regions.

Additionally, low-density zoning works in parallel, as it sets limits on the amount of development in a specific area. This serves to reduce impervious surfaces and can help maintain the natural drainage characteristics of the landscape. By encouraging fewer structures to be built, especially in flood-prone areas, these zoning regulations collectively aid in floodplain management.

In contrast, the other options do not effectively combine strategies that focus on both zoning regulations and site design to limit development in flood-prone areas. For example, while subdivision design for cluster development and regional planning may involve considerations for flood risk, they may not specifically emphasize the need to avoid floodplains as strongly as the correct answer does. Therefore, the combination of cluster development on higher ground with low-density zoning is more effective in promoting safe building practices in relation to flooding.