New York State Resilient NY Flood Mitigation Studies, Buyouts, and Floodplain Restoration Projects
Multiple serious flood events, hurricanes, and storms have prompted New York State’s (NYS) Department of Environmental Conservation (DEC) to develop a range of mitigation and adaptation initiatives to address future flood hazards and improve community resilience. The state is completing a series of Flood and Ice Jam Mitigation Studies within 48 high-priority watersheds across New York State - as a part of an initiative called Resilient NY - to identify the causes of flooding and ice jams and to evaluate priority mitigation projects, like buyouts, to reduce risks. New York’s example is noteworthy for selecting buyouts as part of a comprehensive flood-risk mitigation analysis as a result of Flood and Ice Jam Mitigation Studies, compared to other buyout programs that utilize standalone eligibility criteria based on existing floodplain maps (e.g., a property is eligible for buyouts based on flood zones). Where buyouts are identified as a priority option to mitigate future flood risk, DEC can work with local governments through a unique partnership to remove structures from vulnerable areas and restore floodplains. Specifically, the state can oversee and provide support for locally led and administered buyout programs that can be applied across the state’s watersheds. This data-driven, state-local approach to buyouts can serve as a model for other jurisdictions considering buyouts and floodplain restoration as managed retreat strategies at the community level, that would benefit from statewide consistency, assistance, and resources.
Managed Retreat Examples
Resilient NY Flood Mitigation Studies
In November 2018, NYS announced $3 million in funding for Resilient NY Flood Mitigation Studies to address the causes of flooding on a watershed scale, and help to identify and evaluate priority mitigation projects to reduce flood and ice jam risks. The Flood and Ice Jam Mitigation Studies are being implemented by NYS DEC and Office of General Services, with funding from the New York Environmental Protection Fund (state funding for capital projects that both protect the environment and enhance communities). These studies will be undertaken in 48 high-priority flood-prone watersheds throughout the state, and will include a plan to assess and improve the overall flood risk and ecology of riparian corridors. The state is incorporating hydrologic and hydraulic modeling to evaluate the effectiveness of proposed mitigation projects.1 These studies will also include the latest climate change forecasts.
The Flood and Ice Jam Mitigation Studies present a unique approach for a jurisdiction to select priority areas for buyouts. Here, NYS does not identify areas for buyouts based on criteria like whether a structure is not suitable for elevation within a certain flood height or will not be protected by hard structures, like a levee system. Instead, NYS looks at flood mitigation comprehensively by mapping the various types of inland flooding risks facing riverine communities and their causes and suggesting how those causes can be mitigated through different solutions. Simply, the state proposes potential flood mitigation strategies based on the causes of flooding it identifies through its Flood and Ice Jam Mitigation Studies. This watershed approach allows for mitigation strategies to be tailored to individual flood risks based on this hydrologic and hydraulic modeling.
State Support for Buyouts
Flood and Ice Jam Mitigation Studies can serve as the foundation for flood buyouts in the state, such as the New York City-Funded Flood Buyout Program, by helping to identify from a strategic point which areas need buyouts as a result of poor land-use planning, compared to areas where a different adaptation strategy is more appropriate. For example, existing infrastructure that is not built to address current hydrologic conditions like precipitation events can cause significant hydraulic problems causing water to backup and lead to flooding events, which may necessitate either buyouts, infrastructure upgrades, and/or replacements as alternatives. Differentiating between poor land-use planning issues and infrastructure issues, or the combination of both or other factors, can enable decisionmakers to design more strategic adaptation solutions to yield the greatest benefits.
Floodplain Restoration Projects
In addition to Flood and Ice Jam Mitigation Studies and buyouts, NYS has also worked to address future flood hazards and improve community resilience through floodplain restoration projects. For example, the Town of Whitestown and Village of Whitesboro in Oneida County in New York have undertaken a massive floodplain restoration project along Sauquoit Creek. The project involves removing fill material from Sauquoit Creek’s floodplain and creating natural floodplain benches (low-lying areas that will be constructed next to the creek to temporarily store floodwaters) to provide the creek more room to flood, which will also reduce the size of the regulated 100-year floodplain (or Special Flood Hazard Area). By implementing this project, many homes and businesses will either be removed entirely from the Special Flood Hazard Area and/or flood water depths will be significantly lowered. This will result in property owners no longer being required to obtain flood insurance or premiums will be significantly reduced. To document this change, the Town of Whitestown plans to file a Letter of Map Revision with FEMA. If granted, this Letter of Map Revision can result in increased cost savings for some residents previously in and surrounding the Special Flood Hazard Area.
Considerations and Lessons Learned
Together, these state and other local programs represent a comprehensive, data-driven approach to buyouts that involves coordination across agencies, levels of government, and public-private partners. By using Resilient NY Flood and Ice Jam Mitigation Studies to identify options for reducing flood risks, NYS is able to utilize data, benefit-cost analyses, and other considerations to review and adopt various mitigation measures, including buyouts, infrastructure upgrades, and floodplain restoration. State and local models throughout New York can provide an example for other land-use planners and decisionmakers, including in a coastal context, on how to implement effective flood mitigation and buyout projects through a comprehensive approach, based on scientific and community support to maximize benefits.
Publication Date: 2018
- New York State Department of Environmental Conservation (DEC)
- Managing the Retreat from Rising Seas — New York City, New York: Land Acquisition and Flood Buyout Programs
- Case study
1. There is a difference between “hydrology” and “hydraulics.” Hydrology is the study of how water moves through the water cycle and across the land and other water bodies. In contrast, hydraulics is the study of how water is conveyed through different structures (e.g., pipes, channels) or systems (e.g., rivers, strems) and is often used to evaluate the flow of water through those structures or systems.