2020-21763. Notice of Availability of and Request for Comment on an Interim Report for the Buffalo Bayou and Tributaries, Texas Resiliency Study

AGENCY:

Department of the Army, U.S. Army Corps of Engineers, DoD.

ACTION:

Notice of availability and request for comment.

SUMMARY:

The US Army Corps of Engineers (USACE) requests comments on the alternatives considered to date by the Buffalo Bayou and Tributaries, Texas Resiliency Study (BBTRS) to help inform the Study Team's recommendation to the Chief of Engineers on reducing the flood risk along Buffalo Bayou and its tributaries in Harris and Fort Bend counties, Texas. An Interim Report has been prepared to document alternatives considered to date. The Interim Report, which does not include recommendations or decisions, is being published to solicit input from the public. Seeking this public input prior to identifying a preferred alternative will help ensure the analysis of a complex problem—and ultimately decisions—are effective, responsive, sustainable and understood by the region's communities.

DATES:

Written comments on the Interim Report must be received by email or post-marked by November 2, 2020.

ADDRESSES:

The Interim Report and additional pertinent information about the- study can be found at: https://www.swg.usace.army.mil/​Missions/​Projects/​Buffalo-Bayou-and-Tributaries-Resiliency-Study/​.

Interested persons may submit written comments by email to [e-mail] or by mail to: USACE, Galveston District, Attn: BBTRS, P.O. Box 1229, Galveston, TX 77553-1229.

FOR FURTHER INFORMATION CONTACT:

Ms. Melinda Fisher, USACE, Regional Planning and Environmental Center, at 918-669-7423 or [e-mail].

SUPPLEMENTARY INFORMATION:

1. Introduction and Background. USACE, in partnership with the Harris County Flood Control District (HCFCD), as the non-Federal sponsor, began a feasibility study in 2018 to identify, evaluate, and recommend actions to reduce flood risks along Buffalo Bayou and its tributaries, both upstream and downstream of Addicks and Barker dams. The study will also complete a Dam Safety Modification Evaluation on Addicks and Barker dams. The BBTRS is authorized under Section 216 of the Flood Control Act of 1970 (Pub. L. 91-611) and existing project authority. Section 216 authorizes USACE to review a completed navigation, flood risk reduction, water supply, or related project due to significantly changed physical or economic conditions, and to report to Congress with recommendations regarding modification of the project's structures or operation, and for improving the quality of the environment in the overall public interest.

Existing flood risk management (FRM) projects in the watersheds include the Buffalo Bayou and Tributaries, Texas Project (Project), which was authorized by Congress in the 1930s for the purpose of providing flood control for the City of Houston and Port of Houston. In the 1940s, Addicks and Barker Dams were constructed and a portion of Buffalo Bayou was straightened as part of the completed Project. Since Project completion, a number of physical improvements and operational changes have been made to attempt to mitigate changing conditions within Addicks, Barker, Buffalo Bayou and surrounding watersheds. However, the watersheds continue to experience major flood events, most recently and most significantly Hurricane Harvey in 2017. These flood events, combined with documented increases in precipitation frequencies, continued urbanization of the watersheds, and the potential for flooding events in the future, indicate the Project may need to be modified to further mitigate flood risks.

The study will evaluate ways to reduce flooding in three watersheds—Addicks Reservoir, Barker Reservoir, and Buffalo Bayou—focusing on areas upstream and downstream of Addicks and Barker dams and along Buffalo Bayou. A portion of Cypress Creek Watershed is being considered because overflow from this watershed contributes to flooding in the Addicks Reservoir Watershed. Brays Bayou and White Oak Bayou could be affected by actions benefiting Buffalo Bayou, so impacts to these watersheds will be evaluated. The scope of the study does not include identifying ways to lower flood risk in the lower Cypress Creek, Brays Bayou or White Oak Bayou watersheds.

Since the public scoping meetings held in May 2019 and a newsletter sent in January 2020, the alternatives (potential ways to address the problems) have evolved based on the preliminary results of modeling the physical and economic performance of these actions. The study team used this information to advance the evaluation of several alternatives, remove some from further consideration and add some additional measures for more detailed consideration. To explain this updated information and present the focused array of alternatives, the Study Team is adding a step to the process: release of an Interim Report for public review and comment.

Note:

This is not a Notice of Availability associated with the release of a Draft Environmental Impact Statement (EIS) in accordance with the National Environmental Policy Act. This is an interim step intended to gather public feedback before a Draft EIS is released.

2. Interim Report. The Study Team prepared this Report to present preliminary findings and a focused array of alternatives considered to date that manage risk and reduce damages under existing and future conditions. The report describes the process to identify and screen potential measures to address the problems and meet the purpose and need of the study. The report also describes engineering, economic, social, and environmental analyses conducted to date; it does not identify a preferred alternative nor does it make any recommendations or decisions.

The Interim Report identifies three main problems in the study area—upstream risks to life safety and property when inflows exceed reservoir capacity, dam safety risks if a dam component were to fail during a flood, and downstream risks to life safety and property when flows exceed channel capacity. To address each of these concerns, a number of structural and non-structural measures were considered including but not limited to: Bypass channels, new reservoirs, detention ponds, tunnels, dredging of existing detention ponds and reservoirs, spillway modifications, levees/floodwalls, channel modifications, property acquisition, changes in operations, structure modifications, and prairie/wetland restoration. The Study Team screened an initial array of measures based on technical feasibility, performance, cost, and benefits. Eight alternatives are identified in the interim report as the focused array. These include:

• No Action. No Federal action is taken to reduce future flood risks. This alternative serves as the baseline condition to compare the action alternatives' benefits and costs and is required by policy.
• FRM Alternative 2: Cypress Creek Reservoir. This alternative investigates the feasibility of increasing storage capacity in the upper watersheds through construction of a third reservoir in the vicinity of the Harris-Waller County line in the far western part of the study area.
• FRM Alternative 6: Buffalo Bayou Channel Improvements. This alternative facilitates more efficient conveyance of water by widening and deepening Buffalo Bayou, while preserving or enhancing the natural characteristics of the aquatic and riparian ecosystem.
• FRM Alternative 7: Non-Structural Only. This alternative utilizes actions that reduce human exposure and vulnerability to flooding, but does not attempt to change the hazard. Property acquisition along Buffalo Bayou would lower the risk to lives and properties downstream during all precipitation events, while also allowing for non-damaging larger releases from the reservoirs during more severe events.
• FRM Alternative 8: Combination Plan. This alternative utilizes a combination of FRM Alternative 2 and 6, which includes construction of a third reservoir and channel improvements to Buffalo Bayou.
• Dam Safety (DS) Alternative 4: Tolerable Risk. This alternative increases the spillway capacity and prevents overtopping by reinforcing all four spillways of Addicks and Barker dams. The north spillways would be removed and replaced with stepped roller compacted concrete (RCC) and the south spillways would be replaced with articulated concrete block.
• DS Alternative 5: Tolerable Risk + As Low as Reasonably Practicable. This alternative is similar to DS Alternative 4, except that all four spillways would be removed and replaced with stepped RCC.
• System Operations. This alternative involves acquiring additional lands to efficiently and safely operate the reservoirs given the changed circumstances. A range of reservoir elevations are being considered and could extend from current Federally-owned government land to elevation 112 at Addicks Reservoir and elevation 105 at Barker Reservoir. This would involve acquisition of between 14,868 and 24,707 tracts of land and involve relocation of 10,606 to 21,302 residential properties and 259 to 492 commercial properties.

3. Public Participation. USACE and HCFCD are committed to proactively informing and engaging with the community and stakeholders to reach effective and implementable flood risk management solutions. These agencies intend for public review of the Interim Report to provide input on the alternatives and the complexity of developing solutions. Public and resource agency feedback on the Interim Report will inform the next level of evaluation to identify a Tentatively Selected Plan (TSP). The TSP may be a single alternative or comprised of several alternatives from the focused array under consideration.

Solicitation of Comments: The USACE is soliciting comments on the Interim Report from the public, Federal, State, and local agencies, elected officials, Tribal Nations, and other interested parties. The public comment period will begin [DATE OF PUBLICATION] and written comments may be submitted by email or through postal mail at the addresses provided above.

Meetings: Due to the “Proclamation on Declaring a National Emergency Concerning the Novel Coronavirus Disease (COVID-19) Outbreak” issued on March 13, 2020, no in-person meetings will be held. The USACE will host informational sharing sessions intended to provide an overview of the report and findings to date. The study website provides the dates and times of the information sessions, as well as up-to-date access details.

4. Identification of Tentatively Selected Plan and Availability of Draft EIS. Depending on input received on the Interim Report, USACE estimates issuing a Draft Feasibility Report and Draft Environmental Impact Statement for public review and comment in early 2021. At that time, USACE will provide a 45-day public review period, in accordance with the National Environmental Policy Act (NEPA). USACE will notify all interested agencies, organizations, and individuals of the availability of the draft document at that time.

Christopher G. Beck,

Brigadier General, U.S. Army, Commanding.