Introduction This report is a brief summary of House and Senate procedures for reaching agreement on legislation. It discusses the provisions of House Rule XXII and Senate Rule XXVIII as well as other applicable rules, precedents, and practices. The report focuses on the most common and customary procedures. There are many exceptions, complications, and possibilities that are not addressed, and the House and Senate may modify or waive their procedures by unanimous consent or by other means. Acting on the Same Bill The House and Senate must pass the same bill or joint resolution, and they must reach full and precise agreement on its text before it is submitted to the President for his approval or veto. The same requirements apply to a concurrent resolution and a joint resolution proposing a constitutional amendment, although neither receives presidential action. At some stage of the legislative process, therefore, the House must pass a Senate bill or the Senate must pass a House bill. The simplest way of meeting this requirement is for one house to pass its own bill and send it to the "other body," which then considers and passes it, with or without amendments. Frequently, however, House and Senate committees each develop their own bills on the same subject. In these cases, one house often debates and amends the bill reported by its committee but then amends and passes the corresponding bill that the other chamber has already passed. For example, after the House passes a bill, it frequently takes up a bill on the same subject that it has already received from the Senate. The House then amends the Senate bill by striking out the text passed by the Senate (striking out all after the enacting clause) and replacing it with the text of the House bill it has just passed. The House then passes the amended Senate bill. In this way, the House passes two bills with exactly the same text, but the Senate bill is the one likely to become law because both houses now have passed it, although with different provisions. Much the same thing could happen in the Senate. After considering its own bill, the Senate, by unanimous consent, could take up and pass the House bill after amending it with the text of the Senate-passed bill. Because this action would take unanimous consent in the Senate, however, the Senate might choose instead to begin consideration of the similar House bill. The floor manager could offer as the first amendment to the House bill a full-text substitute consisting of the text of the Senate bill. This process is usually routine, but it can become more complicated. For instance, the Senate may pass one bill on several related matters before the House passes two bills of its own that address the same subjects. After the House passes its two bills, it may take up the one Senate bill and replace the text of that bill with the texts of both of its own bills. In other instances, the House and Senate may confront political and procedural situations that make it convenient for them to include their versions of legislation on one subject as amendments to some third bill on an unrelated subject that serves as a convenient "vehicle." Such arrangements can be necessary because the House and Senate cannot begin the formal process of resolving their policy differences until these differences are embodied as amendments by one house to the version of the same bill as passed by the other. Amendments Between the Houses After one house passes a bill and the other then passes it with amendments, the House and Senate may attempt to resolve the differences between their positions. When confronted with a major bill, the two houses have historically created a conference committee for this purpose. However, a conference may not be necessary if they can reach an agreement through informal negotiations and an exchange of amendments between the houses. The amendments of one house to a bill from the other may be amended twice as the bill is sent ("messaged") back and forth between the House and Senate. Suppose, for example, that the Senate passes a House bill with amendments. The House can accept (concur in) the Senate amendments, in which case the differences are resolved. Alternatively, the House can amend the Senate amendments (concur in the Senate amendments with amendments). These House amendments are first degree amendments between the houses. The Senate can then accept (concur in) the House amendments to the Senate amendments, which would produce agreement. Or the Senate can concur in the House amendments to the Senate amendments with further Senate amendments, which are amendments in the second degree. At this stage, the House can concur in the most recent Senate amendments, but it cannot propose new House amendments to them because they would be third degree amendments, which are not permitted. (Of course, exactly the same process can occur in reverse if the House passes a Senate bill with amendments.) In both chambers, the prohibition on third degree amendments between the houses can be waived. The House might do this by special rule, suspension of the rules, or unanimous consent. In the Senate, unanimous consent is necessary to agree to an amendment in the third degree, unless the House has already waived the rule, in which case further degrees of amendment are permitted in the Senate. If the House and Senate adamantly defend their last amendments, they can send the bill back and forth several more times. In the unlikely event that neither house retreats from its last position or is willing to discuss a compromise in conference, the bill ultimately dies. It cannot be shuttled back and forth indefinitely. This process rarely results in stalemate, because the two houses either reach agreement or decide to submit their differences to a conference committee. However, an exchange of amendments sometimes takes the place of a conference. Once the two houses pass their versions of the same bill, the members and staff of the House and Senate committees of jurisdiction often meet informally to compare the two versions and discuss a compromise. If they reach an agreement that other concerned Representatives and Senators also accept, the House can, for example, concur in the Senate amendment with a House amendment that embodies the negotiated agreement. If the Senate then accepts (concurs in) this House amendment, the House and Senate have resolved their differences through the informal equivalent of a conference committee. Considering Amendments from the Other House House amendments to a Senate bill (or House amendments to Senate amendments to a House bill) are privileged for floor action by the Senate. This means there is no debate on whether to take up the House amendment. Instead, a Senator, most often the majority leader, typically requests that a House amendment be laid before the Senate. Motions to dispose of the House amendments—such as motions to concur or to concur with amendments—are debatable and, therefore, subject to filibusters. It is possible for the majority leader to move that the Senate concur in the House amendment and then propose motions that preempt all other available motions. This is often referred to as "filling the tree" on a motion to concur. If the majority leader can garner the necessary support to end debate on the motion to concur (60 Senators, assuming no vacancies), then both further amendment to the House amendment and extended debate can be avoided. The Senate sometimes arranges to consider a House amendment by unanimous consent. Like the Senate, the House sometimes acts on Senate amendments by unanimous consent. Until the House officially disagrees to Senate amendments to a House bill (or Senate amendments to House amendments to a Senate bill), these amendments are usually not privileged for consideration on the House floor. No motion is in order to concur in the Senate amendments, with or without amendments. When there is little or no controversy, the House often accepts or amends the Senate amendments by unanimous consent. Otherwise, the House can usually do so only through a motion to suspend the rules or under a special rule recommended by the Rules Committee and adopted by the House. A motion that is privileged at this stage is a motion to disagree to the Senate amendments and go to conference, but this motion must be made at the direction of the committee that originally reported the bill to the House. Both houses cannot consider the same bill at the same time, because the House or Senate can act only if it has the "papers." The papers are comprised of the official copy of the bill as passed by the house in which it originated, the official copies of amendments by either house, and the messages by which each house informs the other of the actions it has taken. After one house acts on a bill or amendments from the other, it returns all the papers with an accompanying message describing its action. Thus, the House and Senate always act in sequence as custody of the papers changes hands. Going to Conference Before a conference committee is created to resolve disagreements between the two houses, the House and Senate must each state disagreement over a bill, either by disagreeing to the amendments of the "other body" or by insisting on its own amendments. So long as one house concurs in the amendments of the other and proposes its own amendments, there is no formal disagreement. But at any point during an exchange of amendments between the House and Senate, either house can propose that they can go to conference instead. The two houses usually decide in one of two ways to establish a conference committee. When the Senate passes a House bill with amendments, for example, it can immediately insist on its amendments and request a conference with the House. The House almost always agrees to the conference, although it need not do so—for example, it could simply agree to the Senate amendments instead. At other times, however, when the Senate passes a House bill with amendments, it may merely send back the bill and the amendments in the hope that the House will accept the Senate's amendments, making a conference unnecessary. If the House does not accept the amendments, it can disagree to them and request a conference. The Senate normally then insists on its amendments and agrees to the conference, after which it informs the House and returns the papers. Of course, the equivalent of either sequence of events may occur after the House passes a Senate bill with amendments. Both chambers sometimes agree by unanimous consent to the necessary procedural steps to send a measure to conference. In the House, if there is an objection to the unanimous consent request, then a privileged motion can be made, at the direction of the committee(s) of jurisdiction, to disagree to the Senate amendment (or insist on the House amendment) and request (or agree to) a conference with the Senate. If unanimous consent cannot be reached in the Senate, then a motion can be made to authorize a conference committee, which is subject to debate under regular Senate rules. If a cloture motion to end debate is filed on this motion, however, it matures after just two hours of debate. If three-fifths of the Senate agrees to invoke cloture, then the Senate could immediately vote to approve the motion to authorize a conference. No further debate of the motion would be in order. Appointing and Instructing Conferees Each house usually appoints its conferees (also known as managers) immediately after deciding to go to conference. The Speaker appoints House conferees. The Senate frequently decides, by unanimous consent, to authorize the presiding officer to appoint "the managers on the part of the Senate." The Senate could also empower the presiding officer to appoint conferees, or appoint conferees directly, through the motion to authorize a conference, discussed above. The chairman and ranking minority member of the committee or subcommittee that reported the bill are almost always conferees. They also play a major part in deciding who else is appointed. The committee or subcommittee leaders usually prepare a list of conferees from their chambers that the Speaker normally accepts and the presiding officer of the Senate always accepts. The party leaders may also become involved in selecting conferees, especially if the bill is particularly important, if it was reported by two or more committees, or if amendments to the bill from the other house touch the jurisdiction of more than one committee. Most conferees are members of the committee that reported the bill. In the case of a bill that involves the jurisdiction of more than one committee, members of each committee are often appointed as conferees with authority only to negotiate an agreement with respect to the subjects or provisions of the bill that fall within the jurisdiction of their committees. Thus, some members may be designated as conferees for purposes of the entire bill while others are appointed only to address a specific section or title. Representatives may also be appointed as conferees for limited purposes when the Senate proposes a nongermane amendment that is within the jurisdiction of another House committee. In addition, the Speaker may appoint other Representatives who, for example, offered important floor amendments. The list of conferees generally reflects the party balance in each house. The House and Senate do not have to appoint the same number of managers, and they frequently do not. House conferees vote as a delegation, as do Senate conferees, and a majority of each delegation must sign the conference report. Thus, three Representatives have the same voting power in conference as 30 Senators. Each house is likely to appoint a larger number of conferees when the bill involves the jurisdiction of more than one of its standing committees. A Representative or Senator may move to instruct the conferees from his or her chamber immediately after that house agrees to go to conference but just before the conferees are appointed. For example, the House can instruct its managers to insist on the House position on a particular amendment, or the Senate can instruct its managers to recede to the House position on another amendment. However, instructions to conferees are never binding; no point of order lies against a conference report that is inconsistent with House or Senate instructions to its conferees. The House can also instruct its conferees if they do not report within 45 calendar days and 25 legislative days after being appointed (or 36 hours after being appointed during the last six days of a session). Conference Rules and Reports Conference committee meetings are open to the public unless the conferees vote to close them, and the House must vote to authorize its conferees to do so. Both chambers also have guidelines concerning conference meetings, generally encouraging frequent meetings with open discussions, but these guidelines are often waived or in some cases are not procedurally enforceable. Beyond these guidelines, there are virtually no House or Senate rules governing conference meetings. Conferees select their own chairman and usually work without formal rules on quorums, proxies, debate, amendments, and other procedural matters. Conferences are negotiating forums, and the two chambers allow conferees to decide for themselves how best to conduct their negotiations. It is most common that a conference committee holds a single public meeting, sometimes for members to offer opening statements only. However, the House and Senate have important, and roughly the same, rules governing what decisions conferees can make. Conference committees are established to resolve disagreements between the House and Senate over their versions of the same bill. Therefore, the authority of conferees is limited to matters in disagreement. As a general rule, they may not change a provision on which both houses agree, nor may they add anything that is not in one version or the other. Furthermore, conferees are to reach agreements within the "scope" of the differences between the House and Senate positions. For example, if the House appropriates $10 million for some purpose and the Senate amends the bill by increasing the appropriation to $20 million, the conferees exceed their authority if they agree on a number that is less than $10 million or more than $20 million. It is much harder to determine the scope of the differences when they are qualitative, not quantitative. Also, conferees have more latitude under some circumstances than under others. Under a previous practice, when one house would pass a bill and the other would then pass it with a series of separate amendments—each making a change in a different provision of the bill—these amendments were usually numbered, and it was relatively easy for the conferees to determine the scope of the differences over each amendment. This is generally not true, however, under modern practice when the Senate passes a House bill (or the House passes a Senate bill) with an amendment in the nature of a substitute that totally replaces the text of the bill. In this situation, which arises nearly all of the time, there is only one amendment in conference—for example, a Senate substitute for the House version of a bill. The two versions of the bill can take very different approaches to the same subject, making it difficult for the conferees to isolate every point of agreement and disagreement and to identify the scope of each disagreement. Under these circumstances, the conferees may write their own conference substitute, so long as it is a germane modification of the House and Senate versions. If a conference agreement exceeds the scope of the differences or deals with a matter that is not in disagreement, the conference report is subject to a point of order when the House or Senate considers it. The House, however, typically protects a conference report against points of order by adopting a resolution reported by the Rules Committee waiving the applicable rules. The Senate, meanwhile, interprets the authority of its conferees generously, especially when they develop a conference substitute. Furthermore, the Senate can waive its rule with a three-fifths vote of Senators duly chosen and sworn (60 Senators if there are no vacancies). The authority of Senate conferees is further limited by Senate Rule XLIV, paragraph 8. Under this rule, a Senator can raise a point of order against discretionary and mandatory spending provisions of a conference report if they constitute "new directed spending provisions," or what are sometimes called "air drops." Paragraph 8 defines a "new directed spending provision" as follows: any item that consists of a specific provision containing a specific level of funding for any specific account, specific program, specific project, or specific activity, when no specific funding was provided for such specific account, specific program, specific project, or specific activity in the measure originally committed to the conferees by either House. The Senate can waive these restrictions on the content of conference reports by a three-fifths vote of Senators duly chosen and sworn (60 Senators assuming no vacancies). When the conferees reach full agreement, their staffs prepare a conference report that states how they propose to resolve each of the disagreements. Accompanying the report itself is a joint explanatory statement (also known as the statement of managers), which describes the various House and Senate positions and the conferees' recommendations in more detail. A majority of the House managers and a majority of the Senate managers must sign both the conference report and the joint explanatory statement. House rules require that House conferees be given an opportunity to sign the conference agreement at a set time and place. At least one copy of the final conference agreement must be made available for review by House managers with the signature sheets. Each chamber then debates and votes on the conference report in turn. Floor Action on Conference Reports At the conclusion of a successful conference, the papers usually change hands. The conferees from the house that requested the conference bring the papers into conference and then turn them over to the conferees from the other house. Thus, the house that agreed to the conference normally acts first on the conference report. However, this is a practice that is not required by House or Senate rules. The Senate usually takes up a conference report by unanimous consent, although a Senator can make a nondebatable motion to consider it. The report may be called up at any time after it is filed, but it is not in order to vote on the adoption of a conference report unless it has been available to Members and the general public for at least 48 hours before the vote. (This requirement can be waived by three-fifths of Senators duly chosen and sworn or by joint agreement of the majority and minority leaders in the case of a significant disruption to Senate facilities or to the availability of the internet.) Under Senate rules, a report is considered to be available to the general public if it is posted on a congressional website or on a website controlled by the Library of Congress or the Government Publishing Office. When considered on the Senate floor, a conference report is debatable under normal Senate procedures; it is subject to extended debate unless the time for debate is limited by unanimous consent or cloture or if the Senate is considering the report under expedited procedures established by law (such as the procedures for considering budget resolutions and budget reconciliation measures under the Budget Act). Paragraph 8 of Senate Rule XXVIII states that, if time for debating a conference report is limited (presumably by unanimous consent), that time shall be equally divided between the majority and minority parties, not necessarily between proponents and opponents of the report. A point of order may be made against a conference report at any time that it is pending on the Senate floor (or after all time for debate has expired or has been yielded back if the report is considered under a time agreement). If a point of order is sustained against a conference report on the grounds that conferees exceeded their authority, either by violating the "scope" rule (Rule XXVIII) or the prohibition against "new directed spending provisions" (paragraph 8 of Rule XLIV), then there is a special procedure to strike out the offending portion(s) of the conference recommendation and continue consideration of the rest of the proposed compromise. Under the procedure, a Senator can make a point of order against one or more provisions of a conference report. If the point of order is not waived (see below), the presiding officer rules whether or not the provision is in violation of the rule. If a point of order is raised against more than one provision, the presiding officer may make separate decisions regarding each provision. After all points of order raised under this procedure are disposed of, the Senate proceeds to consider a motion to send to the House, in place of the original conference agreement, a proposal consisting of the text of the conference agreement minus the provisions that were ruled out of order and stricken. Amendments to this motion are not in order, and debate is limited only if it had been limited on the conference report. In short, the terms for consideration of the motion to send to the House the proposal without the offending provisions are the same as those that would have applied to the conference report itself. If the Senate agrees to the motion, the altered conference recommendation is returned to the House in the form of an amendment between the houses. The House then has an opportunity to act on the amendment under the regular House procedures for considering Senate amendments discussed in earlier sections of this report. Senate rules also create a mechanism for waiving these restrictions on conference reports. Senators can move to waive points of order against one or several provisions, or they can make one motion to waive all possible points of order under either Rule XXVIII or Rule XLIV, paragraph 8. If the motion to waive garners the necessary support, the Senate is effectively agreeing to keep the matter that is potentially in violation of the rule in the conference report. In the House, the conference report cannot be considered unless it has been available in the Congressional Record or on the House document repository website for 72 hours. Copies of the report and the statement must also be available to Representatives for at least two hours before they consider it. These availability requirements are sometimes waived by a rule reported by the Rules Committee, and they do not apply during the last six days of a session. Typically, the House calls up a conference report under the terms of a special rule that protects the report against one or more points of order if the Rules Committee reports and the House adopts a resolution waiving the applicable rules. The House debates a conference report under the one-hour rule, with control of the hour equally divided between the two parties. However, if both floor managers support the report, a Representative opposed to it may claim one-third of the time for debate. At the end of the first hour, the House normally votes to order the previous question, which precludes additional debate. If Representatives could make points of order against a report, sometimes the House first considers and agrees to a resolution, recommended by its Rules Committee, that protects the report by waiving the points of order. Conference reports are not amendable. Each report is a compromise proposal for resolving a series of disagreements; the House prevails on some questions, the Senate on others. If the House and Senate were free to amend the report, they might never reach agreement. At the end of debate, therefore, each house votes on whether to agree to the report as a whole. However, the house that considers the report first also has the option of recommitting it to conference. But when one chamber acts on the report, it automatically discharges its conferees. As a result, the other house cannot vote to recommit, because the conference committee has been disbanded. If the House and Senate agree to the conference report, the bill is enrolled (printed on parchment in its final form) and presented to the President for his approval or disapproval. Additional Resources The report is based upon the original author's interpretation of the rules and published precedents of the two houses and an analysis of the application of these rules and precedents in recent practice (see "Acknowledgements"). Readers may wish to study the provisions of House and Senate rules and examine the applicable precedents—especially in the sections on "Senate Bills," "Amendments Between the Houses," and "Conferences Between the Houses"—in House Practice: A Guide to the Rules, Precedents and Procedures of the House and the corresponding sections on "Amendments Between Houses" and "Conferences and Conference Reports" in Riddick's Senate Procedure (Senate Document No. 101-28). There is also more detailed information on this subject in CRS Report 98-696, Resolving Legislative Differences in Congress: Conference Committees and Amendments Between the Houses , and CRS Report R41003, Amendments Between the Houses: Procedural Options and Effects .


Background Coastal communities face hazards from coastal storms and flooding that can cause loss of life, property damage, and damage to the environment. More specifically, coastal communities face threats from erosion and damages from waves, wind, and storm surges. For example, during Superstorm Sandy in 2012, shoreline water levels rose across the East Coast, causing billions of dollars in property damage to homes and businesses. These threats can be exacerbated by several factors, including sea level rise and commercial and residential development, according to Corps documents on coastal risk reduction and resilience. For example, rising sea levels increase the risks from regular tidal flooding and coastal storms and new construction along coastlines can increase the number of people and buildings at risk from the storms. The Corps constructs projects to help reduce the risks from coastal storm hazards and mitigate erosion, wave damage, and flooding, which may include the use of hard structures. The Corps has decades of experience developing projects that use hard structures, such as revetments, seawalls, and storm surge barriers, to reduce the risks from coastal storm hazards, according to a 2014 report by the National Academy of Sciences (see fig. 1). Natural infrastructure can also be designed and developed for coastal storm and flood risk reduction purposes. Natural infrastructure can involve several types of natural features that have the potential to reduce risks to coastal areas from storms (see fig. 2). Diverse natural features occur in different areas of the United States. For example, some areas along the Florida Gulf Coast are host to mangroves—coastal wetlands found in tropical and subtropical regions—that can reduce the impacts of high energy waves from storm surges. The extent to which natural infrastructure can reduce risks to coastal areas from storms and flooding depends on the types of natural features being used. For example, underwater vegetation, such as seagrass, has less capacity to reduce wave energy than a coral reef, which is a hard underwater structure, according to scientific studies. According to a 2014 National Academy of Sciences report, in addition to reducing the risks of storms and flooding for coastal communities, projects using natural infrastructure may provide other benefits, depending on the type of natural feature associated with the project. Among other things, natural infrastructure has the potential to enhance commercial and recreational fisheries and create recreational opportunities. For example, natural infrastructure may support fish habitats, which could enhance a commercial or recreational fishery. In addition, wetlands may improve habitats for birds, which could enhance bird watching activities. Similarly, replenishing beaches may provide more beach area for individuals to use for recreational activities, and provide nesting habitat for birds and sea turtles. Corps Organization The Corps’ Civil Works program—responsible for water resources projects—is organized in three tiers: a national headquarters in Washington, D.C.; eight regional divisions; and 38 districts (see fig. 3). Corps headquarters primarily develops the policies and guidance that the agency’s divisions and districts carry out as part of their oversight responsibilities for the water resources projects under the Corps’ purview. Corps districts are responsible for planning, engineering, constructing, and managing water resources projects in their districts, including projects that consider or use natural infrastructure. The Corps has several programs and initiatives related to using natural infrastructure for water resources projects. For example, the Engineer Research and Development Center, the research organization within the Corps, manages a portfolio of research related to water resources projects that includes research focused on flood risk management and coastal systems. The Corps also has an initiative called Engineering With Nature®, which the Corps’ scientists and engineers developed to facilitate using sustainable practices in Corps projects. The Corps’ Water Resources Project Planning Process The Corps develops water resources projects, including coastal storm and flood risk management projects, in conjunction with nonfederal sponsors, such as state and local governments. According to Corps guidance, the planning process for these projects begins with a nonfederal sponsor identifying a problem and approaching the Corps to help develop a solution. Upon statutory authorization for a study and appropriations to fund it, the Corps and the nonfederal sponsor enter into an agreement to conduct a feasibility study for a potential project. Nonfederal sponsors are to participate in the planning process, as well as remain involved through project design, construction, and post-project operations and maintenance. For example, for projects where the Corps constructs hard infrastructure, such as a seawall, the nonfederal sponsor is to assume responsibility for monitoring and maintenance costs associated with the seawall after its construction. In contrast, for a project that involves replenishing a beach, the Corps and the nonfederal sponsor usually share the cost of replenishment for a specific period of time, typically 50 years. The U.S. Water Resources Council’s 1983 Economic and Environmental Principles and Guidelines for Water and Related Land Resources Implementation Studies (Principles and Guidelines) outline the standards and procedures that the Corps is to follow for planning water resources projects, including those with coastal storm and flood risk management objectives. The Principles and Guidelines establish that the federal objective of water resources projects is to contribute to national economic development while protecting the nation’s environment. The Corps implements the planning process outlined in the Principles and Guidelines by conducting feasibility studies for proposed water resources projects. The Corps’ Planning Guidance Notebook (Planning Guidance) provides detailed guidance on how to implement the general process outlined in the Principles and Guidelines for planning water resource projects. The Corps’ feasibility study process includes four major phases and five milestones, as shown in figure 4. The Corps initiates a feasibility study by forming a project team, comprising Corps engineers, economists, planners, and other specialists, to conduct the study. The Corps project team begins with a scoping phase that specifies the problem, such as the potential for coastal storm and flood damage, and identifies opportunities for a project to address the problem. The project team then inventories conditions in the project area, including physical, economic, and social conditions, and forecasts how these conditions may change over the life of a potential project. As it continues the scoping phase, the project team identifies various measures that could address the problem, such as replenishing an existing beach or constructing a seawall. The project team then develops potential individual measures or combinations of measures (e.g., beach replenishment and seawall construction) into an initial list of alternatives. Since 2016, the Corps has been required by statute to consider natural infrastructure in certain circumstances. With its initial list of alternatives, the Corps project team is to then evaluate each alternative by (1) comparing it to the scenario of proceeding with no project; (2) applying criteria established in the Principles and Guidelines; (3) identifying beneficial and adverse effects of each alternative; and (4) considering other relevant factors, such as compliance with environmental requirements. To identify beneficial and adverse effects of each alternative, the Corps uses four general categories established in the Principles and Guidelines, as shown in table 2. The Corps’ Planning Guidance states that project teams should evaluate alternatives using the four categories of analysis, but the evaluation from two categories—National Economic Development and Environmental Quality—must be included in each feasibility study. According to the Planning Guidance, evaluating projects’ potential costs and benefits through these categories of analysis provides a basis for determining which alternatives should be eliminated from consideration, modified, or selected for further analysis. This evaluation can eliminate alternatives that do not meet planning objectives and may narrow the initial list of alternatives to a final list for more detailed analyses and comparison. Corps officials stated that the process of evaluating alternatives can be iterative and is project specific. The Corps project team then is to conduct detailed analyses of its final list of alternatives to compare them to each other and select a recommended alternative. The project team includes the recommended alternative in a draft report with its analysis. The draft report is made available for review and comment by nonfederal sponsors, federal and state agencies, and other stakeholders. The project team incorporates comments into the report, as appropriate, and determines whether the agency will endorse the recommended alternative. The project team finalizes its feasibility study after internal review. The Corps then prepares a report summarizing the proposed plan—known as the Chief’s report—and submits it to Congress for consideration and potential authorization. The Corps Typically Identified Project Costs and Damage Reduction Benefits for Selected Projects That Used Natural Infrastructure Based on our review of Corps guidance and eight selected projects that used natural infrastructure, we found that the Corps typically identified project costs and damage reduction benefits in selecting the alternative, although for some projects it also considered additional benefits, such as recreational benefits. Once a Corps project team develops a final list of alternatives in conducting a feasibility study for a particular project, the project team is to conduct an economic analysis for each alternative. This analysis allows the team to compare costs and benefits directly across the alternatives, including alternatives using natural infrastructure, hard infrastructure, or a combination of the two. Specifically, the project team is to develop estimates for each project alternative’s net economic benefits—benefits minus costs—to identify and select the project alternative with the maximum net benefits. The Corps’ Planning Guidance states that the Corps shall select coastal storm and flood risk management projects determined to have the maximum net benefits. Our review of Corps guidance and eight selected projects identified the following costs and benefits that the Corps generally incorporated into its economic analyses: Project costs. According to the Corps’ Planning Guidance, project costs include three categories: implementation costs, other direct costs, and associated costs. Implementation costs, for example, include planning and design, construction, construction contingency, operations, maintenance, repair, and other costs necessary to implement a project. The eight selected projects that we reviewed included analyses of project costs, which mostly focused on implementation and interest costs. For example, the costs for the Corps’ Jacksonville District Lido Key project included initial construction costs (i.e., beach construction and hard infrastructure designed to reduce shore currents), future beach replenishment costs (i.e., operations related to placing material on beaches to replenish eroding shores), and monitoring costs (e.g., measurement of beach fill, sediment type, and habitat quality). Damage reduction benefits. Reducing damages to existing structures, including homes and commercial buildings, is the primary benefit the Corps considers when identifying benefits for coastal storm risk management project alternatives, according to the Corps’ Planning Guidance. The guidance outlines general steps for estimating damage reduction benefits, which are to be calculated and included in each coastal storm and flood risk management alternative’s economic analysis. In seven of the eight projects we reviewed, the Corps analyzed damage reduction benefits as part of its economic analysis. For example, the Corps’ project team for the New York District Union Beach project determined the potential damage reduction benefits of each alternative by estimating the alternative’s potential to reduce (1) damages to coastal property from flooding and waves, (2) public emergency spending, and (3) administrative costs for the National Flood Insurance Program (see fig. 5). We also found that for some selected projects, the Corps identified and incorporated additional benefits into the projects’ economic analyses, including the following: Incidental recreational benefits. Corps project teams may include in the economic analysis recreational benefits that stem directly from the project alternative but that are incidental to the primary purpose of damage reduction, according to the Corps’ Planning Guidance. Specifically, Corps project teams may include recreational benefits, such as increases in recreational visits because beaches are larger in their economic analysis of project alternatives, but recreational benefits are limited to no more than 50 percent of the total economic benefits used to justify an alternative (i.e., demonstrate that an alternative has greater benefits than costs). After an alternative has been economically justified, the team can use the full estimated recreational benefits with the damage reduction benefits to select the alternative with maximum net benefits. In our review of eight projects, we identified four projects where the Corps project team included recreational benefits in its economic analysis for the project alternative that was selected. For one such project, the Los Angeles District’s Encinitas-Solana Beach project, the Corps’ economic analysis showed that the selected project alternative had lower damage reduction benefits than project costs. However, when the Corps added recreational benefits—as allowed by Corps policy—the combined annual damage reduction and recreational benefits resulted in the alternative having greater benefits than costs (see fig. 6). Other direct incidental benefits. The Corps may also consider other direct incidental benefits in its economic analysis, as appropriate, according to the Principles and Guidelines. In our review of eight projects, we identified three projects that included estimated incidental benefits aside from recreational benefits. The three projects included economic benefits associated with reduced maintenance costs for local communities, whose expenses for maintaining local beaches would decline after the Corps projects were constructed. Other than these reduced maintenance costs, the Corps did not include other types of direct incidental benefits, such as environmental or other social benefits, in the economic analyses for the eight projects we reviewed. According to Corps officials, some project alternatives using natural infrastructure may provide direct incidental benefits that are not included in the economic analysis, such as environmental and social benefits. For example, the draft feasibility study for the New York District’s Jamaica Bay project states that natural infrastructure can provide direct incidental benefits, such as improving ecosystems, filtering water, and improving aesthetics. The Corps acknowledged these incidental benefits and their importance to communities in its draft feasibility study, but did not incorporate these benefits into its economic analysis because they could not be monetized, according to Corps district officials. Corps headquarters officials said incidental benefits that cannot be monetized in the economic analysis are considered in the planning process through the evaluation of other Principles and Guidelines categories. Two reports published by the National Academy of Sciences stated that when assessing project alternatives, the Corps primarily uses qualitative measures to assess benefits that are difficult to monetize but that relegates such effects to secondary status compared to the monetized estimates of costs and benefits. Moreover, a 2004 National Academy of Sciences report found that the Principles and Guidelines outlines a process that focuses on the effects that can be monetized, which does not allow for full consideration of a project’s total economic effects. Nonetheless, for three of the eight projects we reviewed, we found that the Corps modified its approach in selecting the use of natural infrastructure as part of the recommended alternative. For instance, for the Encinitas-Solana Beach project, the Corps granted an exception to its planning process and recommended a locally preferred plan. In certain circumstances, Corps project teams can deviate from the Corps’ Planning Guidance that calls for the Corps to select the project alternative with the maximum net benefits. Corps headquarters officials said that requesting such an exception is the primary method the agency uses for recommending a project alternative that does not meet the Corps maximum net benefits requirement for a project focused solely on coastal storm or flood risk management. For the Encinitas-Solana Beach project, the California Coastal Commission found that the Corps’ proposed alternative with the maximum net benefits was inconsistent with the mission of California’s coastal management program to protect and enhance the state’s coastal environment. In particular, the Commission had concerns about the size of the project and the amount of sand to be added to the beach under the proposed alternative, as well as the potential adverse effects on a nearshore natural reef and marine resources. In response, the Corps’ Los Angeles District worked with the project’s nonfederal sponsors to address the commission’s concerns and revised the project by reducing its size and potentially lessening its environmental impacts. The commission approved the revised project alternative in November 2013. The Corps’ Planning Guidance also allows projects with multiple objectives to incorporate other analyses in selecting a recommended alternative. For the Philadelphia District’s Lower Cape May project, ecosystem restoration was the project’s primary objective, but it also had a coastal storm risk management objective. According to the project’s feasibility study, the project focused on protecting and restoring a freshwater marsh that was being flooded with salt water from storms because of continued beach erosion. The Corps used a cost- effectiveness analysis to meet the primary objective, which compared environmental measures (e.g., the number of acres of habitat restored) with the costs of different alternatives. In addition, this project included a beach component to protect the marsh from saltwater intrusion. In the process of designing beach alternatives, the Corps project team conducted a damage reduction benefit analysis to determine an optimal size for the beach that would provide the greatest net damage reduction benefit to nearby communities. This analysis helped inform the Corps decision to select a beach design option that met the project’s primary objective of protecting the ecosystem, while also providing the most incidental damage reduction benefits to local communities, according to Corps district officials. For the third project, the New York District’s Jamaica Bay project, the Corps incorporated natural features into the project, although it did not directly include the economic benefits of these features in its economic analysis. For the project, the Corps project team recommended an alternative that was designed to address frequent flooding within Jamaica Bay at three locations. The project team incorporated wetlands into the design at one location, along with hard infrastructure. The nonfederal sponsors of the project told us that they advocated for the inclusion of these natural features, where appropriate, because of their risk reduction and ecological benefits. In response to the interests of nonfederal sponsors, the Corps project team developed and recommended the alternative incorporating hard infrastructure, such as floodwalls, along with coastal wetlands. The Corps did not include the risk reduction benefits from the wetlands in the economic analysis, but the draft feasibility study noted that the project was economically justified based on the monetary benefits of the hard infrastructure alone and that the wetlands provided additional benefits that could not be monetized. The Corps Faces Challenges in Developing Cost and Benefit Information for Some Types of Natural Infrastructure and Has Initiated Steps to Address Them Based on our literature review, agency documentation, and interviews with Corps officials and other stakeholders, we found that the Corps faces challenges developing cost and benefit information for some natural infrastructure to help inform the process for selecting project alternatives and conducting economic analyses in feasibility studies. Specifically, these challenges related to (1) assessing the performance of some types of natural infrastructure and (2) monetizing the social and environmental benefits associated with using natural infrastructure. The Corps recognizes the need to obtain additional data to better develop cost and benefit information for some types of natural coastal infrastructure, and it has begun taking steps to do so. Challenge in Assessing the Performance of Some Types of Natural Infrastructure Information is not readily available on the performance of some types of natural features in reducing coastal storm and flood damages, which makes it challenging for the Corps to develop cost and benefit information for these features and compare them to other alternatives, such as those that use hard infrastructure. For example, Corps headquarters officials said that—in contrast to beaches and dunes—there are significant knowledge gaps about the extent to which wetlands, reefs, and subaquatic vegetation can reduce the risks associated with coastal storms by, for example, moderating wave heights and flooding. In addition, there are knowledge gaps about how these natural features will change over time and how any changes might affect the long-term performance of the features. A Corps report from January 2015 also identified knowledge gaps in understanding how some natural infrastructure, such as wetlands, may perform during coastal storms or floods. According to the report, wetlands may reduce storm surge, but in some instances water can be redirected, potentially causing a storm surge increase elsewhere. Corps officials noted that all structures—whether natural or hard—change over time, requiring maintenance and repair, but said that natural infrastructure may change more dramatically than hard infrastructure and over a shorter period of time. For example, a healthy wetland could restore itself and reduce maintenance costs after a major storm or require the Corps to take action to restore the wetland after the storm event, which could increase the costs of maintaining the wetland. Corps officials also stated that there are knowledge gaps regarding whether wetlands can absorb major storm surges and how these features would perform in the event of recurring coastal storms in a short period of time. Specifically, natural features may be damaged during intense storms (e.g., wetlands can erode and vegetation may be stripped apart), which may degrade the long-term performance of the features. Because the Corps does not have information on performance for some natural features, it has been unable to update engineering guidance to include the use of some natural features, according to Corps officials. A Corps headquarters official explained that the agency must first develop a broader understanding of how some natural features, such as wetlands, perform under various coastal storm scenarios over time before it can begin to develop design guidance for using these features for coastal storm protection and flood risk management projects. A Corps headquarters official said that the agency recognizes the need to obtain additional information on natural infrastructure and has initiated steps to address the challenge related to developing information on the performance of some types of natural infrastructure. In particular, in October 2016, the Engineer Research and Development Center began collaborating with several entities, including other federal agencies, international partners, academic institutions, and nongovernmental organizations, to develop guidelines for using some types of natural infrastructure. According to the scoping document, this effort is to entail developing guidelines to support various phases of building natural infrastructure projects, including conceptualization, design, engineering, construction, and maintenance. According to the Corps official, an anticipated key output from the international effort includes developing information on defining performance for different types of natural infrastructure features and options for measuring performance depending on project objectives. The final product is expected to include chapters with information on analyzing natural infrastructure benefits and related monitoring, maintenance, and adaptive management issues, among others. The Corps official stated that the guidelines will not be official Corps guidance or policy, but Corps project teams and other practitioners can use the guidelines as a resource for identifying best practices in planning projects and assessing potential alternatives. For example, the guidelines will include case studies illustrating design and engineering concepts for certain types of natural features. The guidelines are scheduled for publication in March 2020. The Corps has also developed a separate internal initiative to help fill knowledge gaps regarding how some natural features’ performance can provide benefits relevant to flood risk management, among other benefits. Specifically, the Corps’ Engineering With Nature® Initiative is focused on sharing natural infrastructure best practices that are emerging, and communicating the information to staff in the Corps’ district offices and other key stakeholders. According to a Corps official, the goal of this initiative, among other things, is to help familiarize the Corps’ district staff with existing natural infrastructure information and relevant case studies. The Corps’ Galveston and Philadelphia Districts have projects that may incorporate natural infrastructure. For example, the Galveston District is considering opportunities through the Coastal Texas study to use natural features, such as barrier islands, wetlands, and reefs, in combination with hard infrastructure (e.g., levees), to reduce the risks from storms and floods. Similarly, the Corps’ Philadelphia District is considering a plan to design, construct, and evaluate natural features as part of the New Jersey Back Bays Storm Flood Risk Management study. In addition, in 2018, the Corps’ coastal working group initiated a project within the Corps to help identify natural infrastructure knowledge gaps and prioritize key areas for research based on requests for information received from Corps’ districts. The Corps plans to incorporate information gathered from this project into a strategic plan that is intended to help inform research funding decisions for fiscal year 2020, according to a Corps official. Challenge in Monetizing Environmental and Social Benefits Our review of economic literature identified challenges in estimating the total economic benefits associated with using natural infrastructure features. Several studies noted that data for conducting economic analyses are not readily available. For example, one study noted that there is insufficient information on how restoring wetlands might affect the survival of certain endangered species. Such information is needed, according to the study, to provide insight on the extent to which such features might generate economic benefits. Another study noted that because projects that combine natural features with more traditional structures (i.e., hybrid projects) are relatively new, less is known about their effectiveness or their costs and benefits. Finally, according to another study, estimating recreational benefits associated with natural habitats, such as coastal marshes, can be difficult because there is insufficient information about the extent to which the public visits those sites. In the eight projects we reviewed, Corps project teams did not estimate incidental benefits other than recreational benefits or through avoiding maintenance costs for coastal storm and flood risk management projects. As previously discussed, environmental and social benefits are considered incidental benefits, and Corps guidance indicates that they do not have to be included in the economic analysis. On the other hand, when assessing potential alternatives of coastal storm and flood risk management projects in its feasibility studies, the Corps can quantify or describe the benefits qualitatively and consider these effects during the planning process, outside of the economic analysis. For example, the Corps has measures to quantify changes in habitat, such as number of acres of wetlands restored. The Corps can also qualitatively describe habitat benefits for specific species. However, these nonmonetized benefits may not affect the selection of the recommended alternative, which is generally based on the monetized net benefit estimates of each proposed alternative. The Corps has begun developing a process for identifying, describing, and considering a broader array of potential benefits when assessing natural infrastructure alternatives for specific projects. Specifically, a June 2017 memorandum from the Corps’ Director of Civil Works indicated that projects with coastal storm and flood risk management objectives as well as other objectives should consider social and environmental benefits in the formulation, design, and implementation of projects within existing legislation and Corps policy. A Corps headquarters official said that the agency is not attempting to monetize all potential benefits but is considering options for accounting for potential benefits other than through the traditional monetary assessments of costs and economic benefits. A Corps headquarters planning group is currently working on developing an initiative that would identify a process for using a flexible approach for considering the social and environmental effects of natural infrastructure for coastal storm and flood risk management projects. For example, project teams may have the option of determining whether to incorporate nonmonetized social and environmental benefits, such as enhancing public safety in coastal communities, into the decision-making process for selecting the recommended alternative. The Corps official stated that the agency has begun working on developing guidance for this initiative and expects to issue the guidance in calendar year 2019. Agency Comments We provided a draft of this report for review and comment to the Department of Defense. The department provided technical comments, which we incorporated as appropriate. As agreed with your offices, unless you publicly announce the contents of this report earlier, we plan no further distribution until 30 days from the report date. At that time, we will send copies to the appropriate congressional committees, the Secretary of Defense, the Chief of Engineers and Commanding General of the U.S. Army Corps of Engineers, and other interested parties. In addition, the report will be available at no charge on the GAO website at http://www.gao.gov. If you or your staff members have any questions regarding this report, please contact me at (202) 512-3841 or fennella@gao.gov. Contact points for our Offices of Congressional Relations and Public Affairs may be found on the last page of this report. GAO staff who made key contributions to the report are listed in appendix II. Appendix I: Selected Projects with Coastal Storm and Flood Risk Management Objectives Using Natural Infrastructure This appendix presents information on the eight projects that we selected for review with coastal storm and flood risk management objectives that the U.S. Army Corps of Engineers (Corps) constructed and that included natural infrastructure. We randomly selected eight projects across Corps districts on the Atlantic, Gulf, and Pacific coasts. In seven of the eight projects, the Corps recommended alternatives with either beaches or dunes as the type of natural features to be used for coastal storm and flood risk reduction (see table 3). According to several Corps district officials we interviewed, alternatives featuring beaches are often most appropriate because other natural features, such as wetlands, would not survive the impacts of the high-energy storm waves in open ocean coastal areas where these projects are located. Appendix II: GAO Contact and Staff Acknowledgments GAO Contact Staff Acknowledgments In addition to the contact named above, Alyssa M. Hundrup (Assistant Director), Leo Acosta (Analyst-in-Charge), Mark Braza, Eric Charles, Timothy Guinane, and Jeanette Soares made key contributions to this report. Important contributions were also made by John Delicath and Sara Sullivan.