Buffalo Bayou Community Plan (BBCP)

The original USACE cost estimates for the buyouts were later reviewed and found to be significantly underestimated. Property values in the affected areas have appreciated considerably, making widespread buyouts even more costly. We submitted a 32-page response to the USACE 2020 interim report which is available for review on the Houston Stronger webpage which provides more details on this item.  But, in addition to the cost of the buyouts, the construction of the Buffalo Bayou widening from the reservoirs all the way to the Ship Channel would have been very costly on top of the land buyouts.

Beyond the financial considerations, buyouts alone do not address the core challenge of floodwater storage. Even if structures were removed, there would still be a need for substantial upstream retention to reduce peak flows. Simply expanding conveyance without added storage would create unacceptable downstream impacts and undermine long-term flood resilience. Additionally, increasing conveyance through Buffalo Bayou to accommodate 15,000 cubic feet per second (cfs) of floodwater conveyance would probably cause severe channel erosion and environmental degradation. During Hurricane Harvey, similar high-flow events led to the loss of significant parkland and ecological damage along the bayou.

Early in our study we did consider that some neighborhoods along the tunnel’s path could have an inlet lead into the tunnel.  However, the Buffalo Bayou Tunnel Study is now being done by the USACE, and we are not sure if this concept of connecting certain neighborhoods into the tunnel is still being studied.  The USACE is expected to issue their report by the end of 2025.  Additionally, HCFCD is looking at a potential system of tunnels for Harris County, known as the SAFER Study. There is the potential for eight different watersheds in which a tunnel may be a good option for improving flood mitigation in that area.

During our early study of the tunnel concept, we did consider some of these issues. Currently, a large volume of water enters the Ship Channel from Buffalo Bayou often carrying debris, sediment, and contaminants that contribute to erosion and water quality degradation.  A tunnel has the potential of managing the flow more effectively, delivering water in a controlled manner, and reducing sediment load and erosive impacts.  Turbulence can be reduced by use of a stilling basin at the tunnel outlet.  These items will need more detailed study including potential treatment needs and long-term maintenance.

We assumed a water level of 13 feet in Galveston Bay.

HCFCD has been working with the USACE to develop a new methodology that will evaluate a  Comprehensive Benefit Cost Ratio which will consider multiple additional benefits for a project other than cost.  These benefits will consider social, economic, and environmental benefits and impacts while evaluating flood mitigation effectiveness. In addition, the economic benefits will be considered not only at the national level but also at a local or regional level. The Harris County Flood Control District is working to develop this comprehensive model in association with the USACE. We are hopeful that the Tunnel component will meet the benchmark set by the new methodology.

Yes, some analysis has been done regarding “self-mitigating” impacts for Component 2. There are specific regulatory approaches to self-mitigate wetland losses in the same project area.  The proposed excavation and restoration of the wetland areas in the reservoirs can use these self-mitigating approaches. The wetlands resulting from the restoration of the reservoirs will have hydrologic and vegetative properties which lead them to be of a higher wetland value than the existing conditions. A more detailed evaluation will be required to determine the extent of mitigation necessary, if any, and to estimate associated costs.  This will help ensure that each component is both environmentally sound and technically feasible.  (This answer is also applicable to Components 3 & 4).

We asked a geotechnical engineer to provide a preliminary assessment of the structure of the proposed hills, and he concluded that the concept is feasible.  A similar feature has been built in Houston as part of the Sims Bayou project.  Soil compaction during construction is key, but additional geotechnical studies need to be done before moving forward.

The excavation of the reservoirs tie into the existing outfall elevation of the flood gates.  If you excavate and run into groundwater, it will flow out of the gates so storage in the reservoirs should be at full capacity when needed.  The groundwater will help keep the permanent pools supplied with fresh water between rainfalls, and the permanent pools help increase the capacity of the reservoir because they can be completely “flat”, whereas a dry bottom reservoir has to have a slope to drain, and this makes a large difference in volume, given the scale of the reservoirs. The other benefit of capturing the existing groundwater in a controlled way is that the water could offer a range of environmental benefits. Managed releases could help sustain downstream base flows during dry periods, improving downstream water quality and supporting aquatic life. The groundwater could also be used to enhance wetland and riparian habitats, restore seasonal prairie wetlands, and provide critical resources for migratory birds and other wildlife. By aligning reservoir management with ecological needs, these improvements could strengthen the resilience of both natural systems and surrounding communities.

The proposed intercept channels are located on federal land and could provide valuable habitat.  Where these channels connect to existing waterways, erosion control measures would be essential.  There are proven strategies, many inspired by natural systems like those found on the Katy Prairie, which can effectively manage erosion while enhancing ecological function.  The intercept channels are intended to collect sheet flow from adjacent neighborhoods and runoff from the constructed hills, and they, and existing streams dropping into the reservoirs will want to have habitat-rich, wildlife-friendly and possibly kayak-friendly erosion control “rapids” or “step pools” to bring the water down to the main reservoir pool elevations. As these are conceptual plans, more specifics would be developed during a feasibility study.

There is the possibility of the need for a conservancy type entity; an example is the Houston Parks Board which could take on the operation of certain trails, recreational assets, etc. for the City of Houston. Currently, the USACE develops leases or agreements with other entities to develop and manage recreational and environmental elements in the land surrounding the reservoirs and conservancies have proven to be an effective tool to bring private and philanthropic resources to bear on the improvement of and management of large public spaces in Houston.

Thank you for this information, we will add this to our maps and integrate them into our planning efforts.

Yes, absolutely. Components 2, 3, and 4 all lend themselves to being phased in and completed in smaller pieces.  We are currently focused on identifying opportunities within Components 3 & 4 such as land conservation and nature-based detention/retention that could be implemented more quickly and still provide meaningful flood mitigation and ecological benefits.  While the larger infrastructure elements will take time, we recognize the value of phased, incremental actions that can deliver early wins for the community.

Yes, up to 27,000 acres is potentially achievable in a contiguous area, more may be available depending on funding. Land acquisition would be by voluntary agreement.

Yes, for the most part, Component 4 is non-structural.  However, since we need significant parcels of land for our nature-based conservation and restoration strategies, we hope to meet with the development community to explore opportunities for cooperation with them, especially for the recommendations offered in Component 3.

Yes, we agree that the possibility of acquiring 10,000 additional acres is closing quickly due to accelerating development pressures. The Harris County Flood Control District is actively pursuing some land acquisitions for detention and natural area preservation, but to secure land at the necessary scale and pace, significant funding is required. We are increasingly competing with residential and commercial developers, as well as wind and solar energy projects, all of which can offer higher prices and faster transactions. Rapid action and adequate financial resources are essential to meet our conservation goals before these lands are lost to other uses. CPC is working with various funders and with other entities to acquire land through conservation easements, a mechanism that can reduce the cost of protecting these lands by 40 to 50% lower than the fair market value of acquiring the property in fee.