Which of the following flood mitigation might a city use?

1. Building flood walls or levees

2. Implementing green infrastructure, such as rain gardens and permeable pavement
3. Installing stormwater retention ponds
4. Elevating buildings in flood-prone areas
5. Implementing zoning regulations to restrict development in floodplains
6. Implementing early warning systems for residents
7. Restoring wetlands and natural floodplains to absorb excess water.