Objective 2.2:

Consider high-value opportunities to avoid development in areas that provide natural flood mitigation, and to integrate natural and nature-based solutions into development requirements.

The Need

As areas in Region Seven experience population changes and development pressures, policymakers are considering ways to preserve land that provides natural flood mitigation benefits. There are many well-documented advantages to prioritizing natural flood mitigation, when possible, over traditional gray infrastructure^{See footnote 1} approaches to flood mitigation. Natural floodplains can slow runoff and provide storage for excess water, reducing the flow rate and velocity of floodwater, thereby helping to reduce the risk of flooding to surrounding areas, infrastructure, and communities.^{See footnote 2} They can also provide important ecosystem services, such as providing habitat for fish, birds, and other wildlife and promoting biodiversity; filtering pollutants and improving water quality; and recharging groundwater resources.^{See footnote 3}

For any local government, regardless of the scale, preserving areas that provide natural flood mitigation can be an important component of a resilience strategy — not just for the immediate communities where the projects are implemented, but also for those adjacent and further downstream as well. The more water that can be stored in place and released slowly, the less strain there is on built infrastructure to provide flood mitigation and the less risk there is of loss of life and property.

In addition to reducing risk and providing ecosystem services, there are other practical reasons to preserve natural floodplains and otherwise integrate natural and nature-based solutions into development requirements. Under state law, local governments in Louisiana are authorized to adopt regulations that will help minimize losses from flooding and that comply with requirements of the National Flood Insurance Act of 1968.^{See footnote 4} As discussed in the Background for Goal Two, parishes and municipalities must agree to comply with federal regulations and participate in the National Flood Insurance Program (NFIP) in order to access federally -subsidized flood insurance coverage, and to receive federal post-disaster financial assistance.^{See footnote 5} To participate in the NFIP, communities must demonstrate that they have floodplain management regulations in place that meet minimum standards set by the Federal Emergency Management Agency (FEMA).^{See footnote 6} However, for communities that go beyond the minimum floodplain management requirements, including through higher regulatory standards and preserving open space, it is possible to realize significant savings in the cost of flood insurance through the Community Rating System, which is discussed further in the Background for Goal Two.

^{Credit: The Water Collaborative.}

There are many options available to local governments seeking to preserve areas that provide natural flood mitigation and to expand or integrate new nature-based solutions into the built environment. While many of the opportunities to preserve large tracts of wetlands and other open spaces that provide natural flood mitigation may arise in rural areas of Region Seven, there are also opportunities to promote natural flood mitigation and stormwater management in more urban areas through nature-based solutions (including low-impact development and green infrastructure practices), discussed further in the infrastructure planning context in Objective 2.4. Various approaches to building community resilience by expanding green space in more urban areas are discussed further in Goal One of the Regional Vision. Natural flood mitigation opportunities related to development requirements or open space preservation should also be considered in the context of housing needs and development patterns; policymakers can refer to Goal 3 and Goal 4 for more information.

This objective calls on Region Seven local governments to identify those areas within their boundaries that provide the greatest potential for nature-based flood mitigation, and to explore options either to protect these areas from development entirely or, should these areas be developed, to incorporate new high-value natural features in development through regulatory or incentive means.

How to Make Progress on This Objective

Local governments can seek to protect and expand natural and nature-based flood mitigation through one or a combination of three types of actions:

• Planning; 
• Land-use and zoning regulations; and 
• Incentives.
  

Additionally, local governments can consider opportunities to acquire and conserve land for flood mitigation or stormwater management purposes, for example through the acquisition of vacant, abandoned, and deteriorated (VAD) properties and conversion to green spaces such as a stormwater park. For more information on these policy options, please see Objective 1.3.

Planning

Two planning approaches that local governments can utilize to preserve and enhance open space areas providing natural flood mitigation include comprehensive planning and watershed master planning.

Comprehensive Planning

As it has been noted in other parts of the Regional Vision (see, e.g., Objective 1.2, Objective 4.1), it is often the case for parishes and municipalities that community and land development (and preservation) begins with and is guided by comprehensive planning. In Louisiana, a local comprehensive plan — referred to as a “master plan” in state statute — is “a statement of public policy for the physical development of a parish or municipality” that is adopted by that parish or municipality.”^{See footnote 7} Parishes and municipalities that adopt master plans are required to consider them when “adopting, approving, or promulgating any local laws, ordinances, or regulations which are inconsistent with that adopted elements of [said plan].”^{See footnote 8} This procedural requirement encourages local governments to take actions that are consistent with their local comprehensive plans.

If parishes and municipalities set policies prioritizing natural flood mitigation projects and the preservation of open space in their local comprehensive plans, these plans can serve as a guiding and coordinating force among subsequent local ordinances and regulations. Ascension Parish is one example of a Region Seven local government with a Master Land Use Plan, which includes a chapter focused on drainage, floodplain management, and wastewater. Comprehensive plans are also an ideal mechanism for setting a holistic vision that integrates housing and infrastructure considerations, with needs for flood mitigation considered in all contexts. For more information related to housing considerations in planning, see Goal Three and Goal Four.

Watershed Master Planning

Another type of plan that Region Seven local governments may choose is developing a watershed master plan. These plans are intended to provide an overall vision and decisionmaking framework for reducing flooding within a watershed. Watershed master plans typically evaluate how different design storms^{See footnote 9} affect runoff within the watershed (including perhaps under future climate conditions as well as current conditions), identify wetlands and natural channels, and recommend regulatory standards, projects, and other strategies to improve flood mitigation.^{See footnote 10} Jefferson Parish developed a Watershed Management Plan with comprehensive recommendations for mitigating flood loss damages, including the recommendation to adopt qualifying ordinances that prohibit development, alteration, or modification of existing natural channels. Regulating development and redevelopment according to a watershed master plan can earn a community credit under the Community Rating System Activity 450, Stormwater Management ⎯ Watershed Master Plan (452.b).^{See footnote 11} 

Land-Use and Zoning Regulations

Local governments can also consider adopting or amending land-use and zoning, subdivision, and other development ordinances to preserve areas providing natural flood mitigation, either alongside the development of a master plan or as a standalone effort. These regulatory approaches can create enforceable development standards and requirements related to natural flood mitigation, while providing regulatory consistency and transparency to the development community.

Zoning and Overlays

One of the most common ways to create consistent development restrictions is through zoning, which establishes permissible uses (e.g., residential, commercial, industrial) for given areas within a jurisdiction's boundaries. Overlay zones or districts can provide an additional layer for regulations depending on special characteristics, such as sensitive environmental features. Overlay zones allow local governments to address the specific needs of discrete geographic areas without needing to amend the underlying use classifications laid out in a zoning ordinance. For this reason, overlays can be a useful tool for preserving natural floodplains and open spaces by restricting development or requiring minimum lot sizes in “sensitive areas” to help limit development-related stormwater runoff. St. Tammany Parish, for example, uses a Rural Overlay to provide greater protection for forests and undeveloped land and place limitations on the percentage of a lot that can be developed. St. Bernard Parish is piloting a resilience district approach, which will implement an overlay district to better encourage green infrastructure and open spaces within a certain area of the community. Zoning approaches that significantly reduce the amount of development can earn a community credit under the Community Rating System Activity 420, Open Space Preservation ⎯ Low-density Zoning (422.g).^{See footnote 12} 

Buffer and Greenspace Requirements

Land-use, zoning, and floodplain ordinances can also be used to establish buffer requirements, which specify that during development, a certain amount of land must remain preserved in its natural state in order to provide ecosystem services like flood mitigation. This can help to ensure that development adjacent to the buffer zone does not suffer from increased flood risks.^{See footnote 13} For example, Tangipahoa Parish requires a “25-foot perimeter buffer of undisturbed green space” for all major subdivisions and special use commercial districts.^{See footnote 14}

More generally, local governments can also require that developers set aside land for greenspace depending on the type or size of a development project. For example, St. Tammany Parish requires a minimum ratio of 580 square feet of greenspace per residential lot for any subdivision development with more than 25 lots.^{See footnote 15}

Buffers and greenspace requirements are additional examples of regulatory approaches that can help meet flood mitigation goals while not prohibiting development outright. Buffer requirements that prohibit buildings and fill within the buffer zone can also earn communities credit under the Community Rating System Activity 420, Open Space Preservation — Open Space Preservation (422.a).^{See footnote 16} Jefferson Parish applies greenspace requirements and standards based on specific zoning districts, overlays, and uses.^{See footnote 17}

Minimum Lot Sizes

Other regulatory approaches, like minimum lot sizes, can similarly provide protection within the floodplain or other environmentally sensitive areas without prohibiting development outright. Setting a minimum acreage for lots to be developed, local governments can enhance natural flood mitigation by effectively limiting the concentration of development (and therefore impervious surface) that is permitted. Minimum lot sizes (of five acres or more) can also earn a community credit under the Community Rating System, Activity 420, Open Space Preservation ⎯ Low-Density Zoning (422.g).^{See footnote 18} St. John the Baptist Parish applies a 25-acre minimum lot size (and limits uses other than those related to conservation or forestry to single-family) within its Environmental Conservation District,^{See footnote 19} a classification that helps to restrict development in low-lying marsh areas or areas that otherwise provide critical ecosystem services. This approach may not be appropriate in all circumstances, however, such as in dense urban areas or areas where housing affordability may be a concern. For more information on housing affordability considerations in urban contexts, see Goal Three, and in a rural context, see Goal Four.

There are two things that should be considered when developing these regulatory approaches:

1. Opting for  low-discretion, rather than high-discretion language will make the expectations and purpose of the approaches clearer; and
2. Fully understand the unintended consequences of the approaches that you are adopting. For example, while a minimum lot size may be ideal for preserving open space it is also cost-prohibitive for certain individuals and communities and may further exacerbate existing affordable housing crises.

To assist local governments in Louisiana with developing comprehensive plans, land-use and zoning ordinances, and other regulatory approaches, the Center for Planning Excellence has produced relevant resources, including a Land Use Toolkit, a Coastal Land Use Toolkit, and an Implementation Guide. Region Seven parishes and municipalities may find these resources useful, particularly when considering developing or updating a comprehensive plan and/or land-use and zoning ordinance. 

Incentives

Finally, incentives can provide another method to help ensure that open space is preserved or new green features are included as a component of development. Incentives can take a variety of forms; several examples are discussed below. Many incentives for open space preservation can achieve a community credit under the Community Rating System Activity 420, Open Space Preservation ⎯ Open Space Incentives (422.f).^{See footnote 20}

Transfer of Development Rights

One example of an innovative method to preserve wetlands and other environmentally sensitive areas in their natural state, which ultimately helps to mitigate flooding, is through a transfer of development rights (TDR) program. TDR provides a market incentive to shift development away from certain areas (in this case, environmentally sensitive areas that provide flood mitigation).^{See footnote 21} TDR offers developers rights to other developable lands (“receiving areas”) in exchange for purchasing development rights from willing sellers in environmentally sensitive areas (“sending areas”), which are then preserved in their natural state. Development rights can be extinguished in sending areas through the private or nonprofit purchase of an entire parcel of land (also known as an “in fee total”) or through the purchase of conservation easements to all or part of a person’s property.  St. John the Baptist Parish envisions potentially creating a TDR program, as indicated in the parish’s Comprehensive Plan Land Use’s Hazard Mitigation Element.^{See footnote 22} For more information and examples related to TDR programs, please see the Georgetown Climate Center’s Managed Retreat Toolkit part on Transfer of Development Rights.

Other Density/Use Incentives

Aside from TDR programs, local governments can offer other types of incentives to preserve open space for flood mitigation purposes by allowing subdivision developers to increase density or decrease lot sizes compared to what would otherwise be allowed in the specified area. For example, Tangipahoa Parish offers the option of “conservation developments,” in which smaller lot sizes are permitted in exchange for preserving stormwater management areas, a majority of which must be contiguous with each other.^{See footnote 23} In order to take advantage of this incentive, a subdivision must meet certain size requirements, and generally the stormwater management area must be in the Special Flood Hazard Area (SFHA) or amount to at least 30 percent of the gross site size if the site is within Flood Zones X or X500 (both of which are deemed lower-risk and outside the SFHA).^{See footnote 24} The parish is also offering incentives for wetlands preservation in major subdivisions consisting of 20 or more acres, or 50 or more lots.^{See footnote 25}

Permitting Incentives

Local governments might consider offering developers non-financial types of incentives like access to expedited permitting processes or shortened review periods to incorporate green space in development plans. Houston completed an Incentives for Green Development study to examine different approaches to encourage green stormwater infrastructure (GSI) in development. The stakeholders engaged for the study indicated that expedited permitting would incentivize greater uptake of GSI in development.

Tax Incentives

Local governments can discourage development in and encourage the preservation of natural floodplain areas by offering tax incentives. In this context, tax incentives could include, for example, programs that lower tax assessments in exchange for an agreement to preserve land in its natural state, and programs that freeze increases in property taxes so long as the environmentally sensitive areas within a project area are preserved and undeveloped.^{See footnote 26}

Crosscutting Practice Considerations and Tips

When considering the most appropriate and feasible ways to preserve or expand areas that provide natural flood mitigation, decisionmakers may find the following crosscutting considerations and practice tips useful:

• Consider flood mitigation needs holistically
• Lead with data
• Prioritize education about the benefits of natural flood mitigation
• Engage communities and other stakeholders
• Coordinate with other authorities in the parish 

These tips are based on priority implementation best practices and considerations most relevant to this specific objective and do not present an exhaustive list for regional and local planners and policymakers. In addition to this objective, decisionmakers should, at a minimum, also refer to Goal Five for crosscutting practice tips and considerations including structuring equitable and inclusive community engagement processes and identifying priority data needs around flooding, drainage, and mitigation options.

It is important to acknowledge that every jurisdiction will be starting from a different place and have a unique local context and needs, among other factors. Therefore, these practice tips could be adopted individually, collectively, or not at all. It will be up to policymakers to work directly with their communities and other key stakeholders and partners to assess and determine potential tools and approaches to implement this goal and objective.

• Consider flood mitigation needs holistically: Flood risks and potential solutions that seek to preserve open space or otherwise maximize nature-based solutions that provide natural flood mitigation should be considered in the context of overall development patterns, housing needs, and affordability concerns. Preserving open space and implementing regulations that otherwise limit development can be costly, and ultimately affect the affordability of new homes; these costs should be considered alongside the flood mitigation benefits of strengthening standards and the overall housing needs and affordability concerns in a parish or municipality. Decisionmakers can refer to Goal Three and Goal Four for more information on how to integrate solutions that promote housing affordability in urban and rural contexts, respectively.
• Lead with data: In prioritizing physical locations that provide natural flood mitigation, decisionmakers should ensure that they are relying on the latest data and science. This includes maps estimating flood depths and extent and precipitation estimates relating to intensity, frequency, and duration of weather events. The Louisiana Watershed Initiative is also working with technical experts to develop hydrologic and hydraulic models for the state’s watersheds, which will support more data-driven decisionmaking when completed. Accurate data and models with a good understanding of uncertainties can help local governments justify decisions regarding areas to protect from development through various planning, regulatory, incentive, or other measures. For more information on prioritizing data needs related to flood mitigation, see Objective 5.2. 
• Prioritize education about the benefits of natural flood mitigation: In order to build capacity and to generate buy-in from the public and elected officials to preserve open space, these audiences should have access to spaces where they can develop a common understanding of the many benefits of natural flood mitigation, including social, environmental, and economic co-benefits. Local governments should consider a variety of approaches to interact with these audiences, such as through developing fact sheets, social media, displays and signs in preservation areas, and through holding meetings and other in-person engagements. 
• Engage communities and other stakeholders: Decisions regarding development limitations or requirements designed to protect or enhance natural areas for flood mitigation should involve robust community and stakeholder engagement. Community members, especially those who are resource-limited and Black, Indigenous, and People of Color (BIPOC) and low-income stakeholders, have direct knowledge about flood challenges their neighborhood is experiencing. As such, any decisionmakers should seek to learn from individuals firsthand about their experiences and priorities. Additionally, decisionmakers should prioritize input from and transparency with the development community throughout the stakeholder engagement process. Effective community and stakeholder engagement practices that decisionmakers can adopt in this context are discussed further in Objective 5.1.
• Coordinate with other authorities within the parish: While inter-parish coordination is important for an overarching regional scale strategy for flood mitigation, intraparish coordination should also be prioritized when considering planning, regulatory, or incentive measures to preserve open space for natural flood mitigation. Planning and environment departments are key partners, but decisionmakers should also identify any other relevant agencies or authorities (e.g., drainage districts, municipalities, parks, open space, and community development or revitalization departments) in the parish that should be involved in order to provide greater legal and policy consistency and coordinated implementation, when possible. Making intraparish coordination standard practice can help avoid conflicting legal or implementation efforts. Additionally, coordination within a parish (and across parishes, if feasible) can help provide greater regulatory consistency to the development community.

The summaries below highlight resources and case studies available in Georgetown Climate Center’s Adaptation Clearinghouse that are relevant to this objective. They illustrate how many of the above benefits, practice tips, and planning, legal, and policy tools were or are being evaluated and used in practice in different jurisdictions. To learn more and navigate to the Adaptation Clearinghouse, click on the “View Resource” buttons.