Letters of Support - Harris County Flood Control District
Transcription
Letters of Support - Harris County Flood Control District
13-0713 Why the Need for MPDP by K. Shanely V. 2013 July 13 Why the Need for the Memorial Park Demonstration Project 1. Buffalo Bayou is no longer a natural stream. Every stream is inextricably linked to its w/atershed, every stream is shaped by its watershed and every stream evolves with its watershed. 95% of the Buffalo Bayou watershed below the dams has been urbanized to suburban densities; and the influx of millions of new people to the Houston metropolitan area over the next several decades will result in on-going, gradual increases in density within the Buffalo Bayou watershed. 2. The past urbanization and the future urbanization have utterly changed the response of the watershed to a rainfall event, with rapid, flashy peak flows within a few hours after a storm event, in comparison to the pre-development response measured in days and weeks. The Addicks and Barker Dam discharges just further exacerbate the stresses placed on the bayou by human activities. 3. Buffalo Bayou will seek to establish what fluvial geomorphologists call a 'dynamic equilibrium' with the new and changing conditions in the watershed, but for this bayou, it will be a moving target for many decades to come. The bayou will work to change its horizontal and vertical geometries in response to the changes forced on it, and these might result in changes of hundreds of feet horizontally and, depending on the location, several feet vertically, as has already occurred in multiple locations along the bayou. 4. This means that the bayou will want to eat into real estate already occupied by gardens structures, houses, condominiums, bridges and utilities. The owners of those properties will fight the bayou and, as they have been doing for decades already, they will line the banks of the bayou with steel sheet piles, bags of concrete, timber walls, gabions, and giant heaps of rubble. They will do what they think they need to do to protect their property. Anyone who has taken a canoe or kayak trip down the bayou will have seen the effects of these band-aid solutions, where one property owner's solution may very likely just shift the energy of the bayou to the opposite bank or to the downstream property owners. Given time and the changing bayou, in a few years most of the bayou will be lined with band-aid solutions installed ad-hoc by property owners intent on protecting their assets, but in the end destroying the natural character of the stream. 5. The bayou is a moving column of water, full of energy, and the only way to properly address changes to the river environment is to take into consideration both banks of the bayou, to acknowledge the changes to the flows coming into the bayou from the watershed, to understand the plan-form the bayou needs to adjust to given a changing flow regime, and to understand the vertical gradient of the thalweg, or profile, of the bayou bed for at least several bends of the bayou. For a bayou the size of Buffalo Bayou downstream of the dams, any solutions to erosion reduction and property protection need to be done in the context of understanding several miles of the bayou in each direction of any single project. 6. The Memorial Park Demonstration Project is an effort initiated by and supported by the Bayou Preservation Association to attempt to apply the best scientific stream restoration practices to a short stretch of the bayou that has been changing rapidly and of which some of the banks had already been armored with steel piles and rip-rap and bio-engineered terraces, resulting in rapid changes to the opposite banks. Page 1 of 4 prepared by Kevin Shanley 7. The Demonstration Project is intended to show how property can be protected with due regard and respect for the physics of river morphology. This is done by adjusting the plan shape of the stream to correspond to the overall shape that the bayou is working to get to by chewing into the banks, but making the adjustments in such a way that they don't endanger homes or other improvements along the way. By making the adjustments at one time as a construction project, the massive amounts of material that the bayou would otherwise chew out of the banks as erosion does not clog up downstream reaches of the bayou. The bed of the bayou is also adjusted to correspond to the new plan-form, with deeper pools at the outer bends and shallower riffles between the bends; this bed profile is important to match to the plan shape of the bayou; otherwise the energy in the stream will work to create a riffle/pool sequence on its own, but it might not initially match the plan shape and it might continue to try to change the plan shape, causing more erosion. 8. This kind of stream restoration work attempts to use only the natural soils already in the bed of the stream and only natural woody material along the outer bends and in the riffles, to help resist erosion right after construction, to help roughen the bend so that the higher energy fast water is moved slightly away from the soil surface of the bank, and, importantly, to enrich the riparian habitat for small fish, reptiles and benthic creatures. Native trees and riparian vegetation is planted back along the banks, tight up against the outer bends so the root systems help secure the bank and so the shade of the branches cools the pools, and further back from the banks on the sandbar side of the bend so that high flows can pass across the bar naturally. 9. The stream restoration work will be messy during construction, but if properly planted with native riparian plants, the work area quickly recovers its lush riparian qualities, and provides better habitat than is provided by a rapidly eroding and degraded stream system. This is something new for our region, and it is why we are calling it a Demonstration Project. We need to examine the project closely, and we need to make adjustments to it as it is underway if necessary, and we need to be sure that the project has adequate follow-up to measure the success of the project from all standpoints; a reduction in erosion and excessive sediment and turbidity in the bayou; re-growth of the riparian and upland native vegetation; reestablishment of wildlife habitat, and improved water quality. 10. Although there are projects in the region that have used some of the principles of fluvial geomorphology, and although they are very different projects, there are lessons from each that we should learn from. a. Sometime in the mid 1990's the footbridge on the north bank of Buffalo Bayou near Glenwood Cemetery was in danger of washing out. An engineering firm replaced the wooden bridge with a steel truss bridge, and re-established the bank of the bayou upstream and downstream of the bridge using a toe of rip-rap and terraces of MSE (mechanically stabilized earth) walls. This is a system of reinforcing the soils with geo-textiles and supporting the front face with a wire mesh (not the same as gabion walls). The bayou bank looked very 'engineered' right after construction, but in a few years, after silt had covered over the terraces and self-sown Green Ash and other trees grew in the silt, and the bank looked completely natural. The lesson here is that that even with an engineered system to protect a piece of infrastructure, and even with no deliberate re-vegetation, nobody could tell that it was not a natural bank. b. The Meyers Park project on Cypress Creek was the first project in the county to deliberately re-establish a fluvial geomorphologically correct flood-bench and riffle/pool sequence to reduce the heavy erosion that was occurring along the park. This project demonstrated the basic rule that coastal streams like ours need to be able to flow out onto a flood-bench at the "channel-forming Page 2 of 4 prepared by Kevin Shanley flow" which is about a two year storm. The flood benches were excavated, and ephemeral wetlands were created along the benches. Riparian trees were planted along the banks and on the flood benches. The initial work appeared very 'engineered', but the first phase is now beginning to grow in, with the trees growing up and vegetation getting well established along the banks. Although the HCFCD required the use of Bermuda grass to initially stabilize the channel, the riparian vegetation has all but obliterated the Bermuda grass along the banks and the channel is appearing more 'natural' with each passing year, but is now a stable channel without the excessive use of concrete or steel. c. The Buffalo Bayou Park, between Sabine and Shepherd Streets, is currently under construction and the nearly completed segments where the HCFCD contractor is working are only In their initial post-construction condition. Fluvial geomorphologists were part of the Flood Control's design team and care was taken to absolutely minimize the amount of new structures in the bayou channel as they work to remove silt and to partially re-establish some of the historic bends of the bayou. Here, as along Cypress Creek, the District required the use of Bermuda grass for the initial erosion control and bank stabilization. A large number of native riparian trees are being planted along the new banks such that there will be an almost continuous canopy of trees along the bayou again. The surface of the ground will receive additional tree and understory plantings as a part of the Buffalo Bayou Partnership part of the project, and it is the intent of the design for the immediate banks of the bayou to NOT be mowed on a regular basis (mowers will not fit between all the trees), but only to receive enough vegetation management to restrict the amount of ragweed and invasive vegetation along the banks. Just upstream of Sabine Street, along the south bank, a pilot planting area was established a year ago, with dozens of very small Cypress, Ash, Sycamore trees were planted, along with a long list of native riparian understory vegetation. With only a year under our belt, and a very dry hot year at that, it is still too early to know what we have learned from this planting, but we hope to find out which native plants are most likely to thrive in these conditions and to provide a frame work for a long-term healthy native riparian ecosystem. 11. The Memorial Park Demonstration Project wants to be different from these other projects; having learned from them that the basic principles work as predicted by the science here with our climate, soils and vegetation, we want the Demonstration Project to be a model of how to set the framework for the restoration of a natural, and "wild and wooly" stream corridor. If the project is successful once it is completed and allowed to mature, this kind of stream restoration might be an effective alternative to the often not so effective structural solutions used as band-aids for individual property owners. We will need to work with the HCFCD and their designers and contractors to build on their fluvial geomorphologic foundation and "roughen" up the finish product with the creation of habitat structures, micro topographic features, and more complex planting schemes. The BPA and the Memorial Park Conservancy might need to help design and maybe even to help fund some of these additional ecosystem features. 12. A denial of the science of fluvial geomorphology, a denial of the unbreakable link between the watershed and the bayou, a denial of the very real changes the bayou is going through right now, and a denial of the very real urges and rights of property owners and government agencies to protect their assets from losses due to an encroaching and eroding bayou ......... Page 3 of 4 prepared by Kevin Shanley ... will condemn the bayou to walls of concrete, bags of cement, banks of concrete rubble and steel sheet piles, each just making the problem worse for neighbors across the bayou, and for those upstream and downstream, in an ever intensifying battle against the soul and spirit of Buffalo Bayou. We HAVE to find the right tools so a natural Buffalo Bayou can co-exist with an increasingly urban watershed and population! The Demonstration Project is just a step in that direction. Page 4 of 4 prepared by Kevin Shanley 13-1013 BBP Letter of Support 14-0225 BPA Letter of Support 14-0331 MPC Letter of Support 14-0601 Steve Lindley Informational THE MEMORIAL PARK DEMONSTRATION PROJECT A Project to repair, restore and reforest Buffalo Bayou June 2014 Earlier this year, the Harris County Flood Control District (HCFCD) applied for a permit from the United States Army Corps of Engineers (Corps) to allow for the work on an erosion control and restoration project known as the Memorial Park Demonstration Project (MPDP). MPDP will restore an approximate length of 5,800 linear feet of Buffalo Bayou, which primarily borders Memorial Park and the River Oaks Country Club, plus up to an additional 800 feet along the Hogg Bird Sanctuary tributary. In this reach of the bayou, there are at least seven (7) significant areas of what is called ‘high bank failure’ (see Figure 1) – that is, where the bayou has completely eroded away the entire slope of the bayou and related plant and shrub cover, including mature trees. These high bank failures have resulted in significant loss of property and the ultimate deposition of sediments and debris downstream, a large part of which has to be dredged and removed from the bayou and ship channel by HCFCD and the Port of Houston Authority (PHA). There is little disagreement that Buffalo Bayou is under a great deal of stress. This stress is primarily caused by the continued urbanization of the Buffalo Bayou Watershed, and the operational practices of the Corps, who manage the Addicks and Barker reservoirs for flood damage reduction purposes, through the staged release of collected storm water from the Addicks and Barker Reservoirs. Where disagreement has arisen on MPDP, centers on the proposed methods to stabilize and restore the bayou and its banks. FIGURE 1 – Seven highlighted areas of erosion along the proposed project area The permitting process being conducted by the Corps, which began in early May, allows for a public comment period on the project, through a Public Notice posted by the Corps. Since the public comment period began on May 1, there has been an effort by a number of individuals and groups to discredit MPDP by using fear tactics and half-truths to make a case that the MPDP is based on bad science and would destroy the bayou as we know it. Facts around the Project: The term ‘riparian forest’ is used a lot in the various commentaries and articles. So it is important to understand what a ‘riparian forest’ is. The United States Department of Agriculture (USDA) describes it is as the forest buffers that are natural or re-established woodlands next to streams, lakes and wetlands. These buffers usually consist of trees, shrubs and grass plantings that are managed to enhance and protect aquatic resources from adverse impacts from the management of adjacent lands1. It should be noted that riparian forest does not mean a specific tree or shrub species, but the area adjoining the stream or river, which in this case is along Buffalo Bayou. Below are aerial photographs of the bayou in 1938 and more recently within the last year – see Figure 2 and 3. As can be seen, the bayou was almost indistinguishable in 1938. Since that time, the buffer zone or riparian forest that runs parallel to the bayou has continued to be destroyed (see photographs below), so that today there are few areas along this reach of the bayou where the trees actually hang over the bayou and provide a closed tree canopy over the bayou. Close-up aerial photographs of the bayou from this most recent aerial (Figure 4), shows us that many trees have fallen into the bayou because of the erosion caused by the movement and expansion of the bayou’s streambed through the stress being put on the bayou system as it tears itself apart in an effort to re-establish a state of balance with the stresses it is encountering. FIGURE 2 – 1938 Aerial image of the proposed project area FIGURE 3 – 2012 Aerial image of the proposed project area 1 USDA National Agroforestry Center, ‘Working Trees Info – What is a riparian forest buffer?’, First Edition May 2012 FIGURE 4 – Aerial Images showing the mature trees that have fallen into the Bayou after a large rain event High Bank Failure with significant mature tree, shrub and vegetation loss High bank failure with tree, shrub and vegetation loss Bank failure with tree and vegetation loss What is causing this stress? As mentioned above, there are two primary causes for the deterioration of the bayou and its streambed. First, there is the continuing urbanization of the Buffalo Bayou watershed area. Whereas in the past, the rain water entering into the bayou might take several days to work its way into the bayou through undeveloped property that allows for saturation of rain waters into the undeveloped landscape, today the water enters the bayou system within minutes because of the addition of impervious cover within the watershed, such as roads, parking lots, buildings and the associated man-made drainage systems. The impact of Houston’s development on the watershed can be seen on the graph below, which is the reading of the maximum flow rate recorded annually at the Shepherd St. flood gauge Figure 5. While rain events vary from year to year, this graphically shows the continued increase in maximum flow rates due to water entering the bayou faster after rain events. The second cause comes from the managed release of water behind the Barker and Addicks reservoirs. Once water accumulates behind the two reservoirs, it is released at a rate of 2000 cfs (cubic feet per second). When water is being released at this rate, it has the effect of raising the bayou level in Buffalo Bayou by approximately 6-8 feet. If this release is sustained for any period of time, the raised water levels permeate the bayou banks. Once the lower levels of the banks are saturated with the higher water levels, instability is created in the banks because of the shear stresses that are placed on the lower portions of the bayou’s slopes. These stresses erode the base of the slopes and cause the slopes to collapse, undermining the ability for vegetation and trees to survive on unstable slopes. This is graphically seen in the failures that are occurring in the high bank areas outlined in Figure 1 and shown in the photographs. Once the vegetation is lost and the banks are exposed, the erosion from future rain events accelerates and expands the loss of land and property in these high banks areas since there is no vegetation or root systems in place to help stabilize the slopes. The rate at which this is happening is alarmingly high. The River Oaks Country Club, for example, has lost from 10-20 feet of property over the past 8-10 years on the western part of its property near the upper end on the project reach. Doing nothing to help prevent the loss of land is not an option. FIGURE 5 – Historical Annual Peak Flow Rate as recorded at the Shepherd Drive USDS gage One of the concerns raised by MPDP opponents is that there will be significant ‘clear cutting’ of the riparian forest. Before addressing the potential loss of some trees, HCFCD had an independent third party perform a vegetation survey along the reach of the project. Within this survey, two areas were covered. First was the area within the proposed final easement of the MPDP and the second area was a 20 foot buffer area just outside of the easement but running parallel to the easement. Within this area, trees that were 8” and greater in diameter were captured by GPS units providing x, y, and z spatial locations. Other information captured for these trees included the condition index, crown diameter, species type, and any noteworthy features about the tree. See Figure 6 of a pictorial of the surveyed trees. There were 972 trees inventoried within and 20 feet beyond the easement. Of these trees, there are 73 dead trees and 899 living trees. The top 4 species found in this area are: Boxelder (220), American Sycamore (115), American Elm (102) and Cherry Laurel (78). These four species represent 515 or 57% of the live trees which are 8” or greater in diameter. As to the quality and condition of the trees, only 225 trees are rated as being in “Good” or “Excellent” condition, which is 25% of the live trees. See Figure 7 for additional tree inventory information. However, when considering any potential loss of trees in this project, it needs to be remembered that MPDP can only be worked within the easement and that just because there is an easement doesn’t mean that work will be performed from easement line to easement line. In fact, there are large areas within the easement that will not be disturbed – see Figure 8. FIGURE 6 – Surveyed trees 8” in diameter or larger within the Easement Area plus a 20’ buffer. Note: This is not a listing or pictorial of the trees that will be removed in the project 600 Trees by Condition Index 489 Number of Trees 500 400 300 223 185 200 100 73 2 0 Dead Poor Fair Good Excellent Tree Condition Index FIGURE 7 – Number of trees surveyed within the final proposed project area easement shown by condition index FIGURE 8 – Limits of the area proposed for active restoration in comparison to the location of trees surveyed When considering the potential loss of any trees, one must consider the area within the easement where ‘cut and fill’ work will be done. In the tree inventory, there are 568 trees or about 63% that are located outside the proposed ‘cut and fill’ lines; thus, only 331 tress (or about 37%) are potentially impacted, some of which are already dead. It should also be noted that within the survey area there are no cypress or magnolia trees (which are native to the bayou) since they were historically harvested for their lumber value during the early days of the Houston area’s development. MPDP proposes to re-vegetate the project area with a much more diverse pallet of native vegetation, and to plant at least 4 times as many trees as would be potentially affected. Summary The Memorial Park Demonstration Project is designed to showcase a holistic, proven stream restoration and bank stabilization technique to enhance the ability of Buffalo Bayou to transport storm water efficiently, stabilize the banks of the bayou, and reduce the transportation of sediment downstream. Short term fixes in only certain spots is not the holistic approach of MPDP. While some may disagree with MPDP because it is not limited to spot repairs of eroded areas, it has been designed using sound scientific data and proven engineering techniques that have been successfully used in many other parts of the country and the world. MPDP is also distinctly different than the project conducted by the Houston County Club that was designed with the objectives of stabilizing one side of the bayou’s bank and providing for an increase in aesthetic appeal. MPDP looks to address both sides of the bayou’s banks as they work in unison with each other. The completed project will result in improved water quality and natural habitat along this stretch of the bayou. Will the growth of vegetation and restoration of a diverse habitat be immediate? No. But this is a collaborative undertaking with a long-term vision for what Buffalo Bayou could once again become: a sustainable, natural bayou system with a diverse setting full of native vegetation and habitat. While there will be some tree and shrub removal along parts of the project reach, this removal will be mitigated by the reforestation and planting of more native trees and shrubs than were removed, which will re-establish the proper plant community appropriate for Buffalo Bayou. In short, while MPDP can only focus on the problems encountered within the proposed project reach, and not the entire Buffalo Bayou watershed, it is an appropriate and best response to the bayou’s stress. Taking no action at all is not an acceptable approach to reducing further loss of property and habitat, and improving water quality. Quick Facts: Project Manager: Harris County Flood Control District Project Engineers: KBR and StanTec General Contractor (CMAR): SpawGlass Civil Environmental Sub-contractor: Shamrock Environmental Project Partners: Harris County Flood Control District, City of Houston and River Oaks Country Club Supporting Entities: Bayou Preservation Association, Buffalo Bayou Partnership, Memorial Park Conservancy Project Length: Approximately 5,800 feet on Buffalo Bayou and up to an additional 800 feet within the Hogg Bird Sanctuary Type of Design: Natural Channel Design originally pioneered by Dave Rosgen Cost: Estimated to be $6.0 million Websites for Additional Information Harris County Flood Control District - http://www.hcfcd.org/P_memorial/ Bayou Preservation Association - http://www.bayoupreservation.org/ Attachments: A - Fact Sheet from Harris Country Flood Control District on the Project B - Memo from Kevin Stanley of the Bayou Preservation Association regarding the Project C - Letters from the Bayou Preservation Association regarding the Project D - Letter from the Buffalo Bayou Partnership regarding the Project E – Letter from the Memorial Park Conservancy regarding the Project 14-0605 Terri Thomas MPDP Support Letter Thursday, June 5, 2014 Dear Bayou Friends, I want you to know my husband and I are homeowners within the reach of the Memorial Park Demonstration Project (“MPDP”), and we support the project completely. Living on the bayou, we have seen and continue to see serious erosion taking place. The silt-laden water is ugly and unhealthy. We believe the benefits of a full reach of natural erosion control far outweigh the construction mess proposed. Some factual information about the project is attached.* This information is unlike the comments I have been reading or hearing from a few. As an example of the type of bio-engineering work that has been proposed, please look at the following five photos which I hope will help to paint a picture of how the MPDP will protect Memorial Park (“MP”), the Bird Sanctuary, River Oaks Country Club (“ROCC”), and the homes along the bayou, as well as improve the water quality and storm water flow of the bayou. Simply planting trees will not work. Photo A - Oct. 2006 Photo B - Oct. 2006 Photos A & B: This is the erosion that was taking place at our home in 2006, also affecting our neighbors’ land. You will notice all the trees which came down with the erosion. Photo C: This is a picture of our bio-engineering work in process. Please notice the destruction to the shoreline which had to take place first to stabilize our shoreline. We used rock at the toe and a bioengineered stair step with native materials, planting many native trees and plants between the steps. Photo C - Mar. 2008 Photo D - May 2014 Photos D & E: These are pictures of the same shoreline from Photos A, B, and C. Six years later, the trees are in place and growing strongly. In Photo E you may even be able to see the silt/sand from the May 28, 2014 flood collecting around the grasses and trees. At the time we were doing our bio-engineering control work, I requested Flood Control (“FC”) to take part in the project and go around their easement on Mimosa Point. Mike Talbott, Director, Harris County Flood Control District, told me they could not do it for me without helping every other homeowner on the bayou with their bandaid approach. I told him that I understood, was disappointed, and I would be back. I am back as a strong supporter of the MPDP, a project which will address both sides of the bayou for about a mile. Dr. Dave Rosgen has developed a natural waterway design for erosion control. I have studied his design, and support it tremendously. I am working with FC to make sure the project is done the best it can be. This region now has the opportunity to do a small complete reach of Buffalo Bayou with this natural erosion design. Buffalo Bayou is a distressed natural waterway. Please take the time to read the factual information about this project!* The Tree Inventory which you may read on the Flood Control website is very informative. It is not an old growth riparian forest which is being destroyed. Yes, go down to the bayou with a plant person and check out what the vegetation by the bayou really is presently. Photo E - May 2014 I hope you will share this letter with your friends and colleagues. I hope some people will consider writing a letter of support to the Corps of Engineers for this fabulous public/private partnership project. All of the public agencies are getting to a financial point that they must partner with private money in order to get projects done. People who love Memorial Park should be thanking ROCC for their willingness to help the park as well as their own golf course. Believe me, if this project is stopped, ROCC will do their own erosion control. Who will help Memorial Park and the Bird Sanctuary then? One of our neighbors has been attempting to get something done to the drainage outfall within the Bird Sanctuary for 14 years. No governmental agency would take the responsibility to pay for the needed repair. This MPDP will finally address the erosion of the Bird Sanctuary from this badly installed drainage outfall without cutting many trees down, but instead building up to the tall slopes with the steps of soil, with native trees and plants planted between the steps. Terri Thomas - 6 Rains Way h: 713-861-1408 cell: 713-807-1902 email: territhomas@comcast.net 14-0616 BPA – USACE Letter Board Members Terry Hershey, Founder Executive Committee Robert Rayburn, President, Community Volunteer J. Tynan Kelly, Past President, Attorney Bruce Heiberg, VP, Signal Creek Architects Jack Sakolosky, VP Community Volunteer Linda Shead, VP, Shead Conservation Solutions Janet K. Wagner, Secretary, J.K. Wagner & Co. Michael Hendryx, Treasurer, Strong Pipkin Bissell & Ledyard Chris Browne, Director, EHRA Elaine Finger, Director, Community Volunteer Jim Robertson, Director, Community Volunteer Frank C. Smith, Jr., Historian, Community Volunteer Elle Anderson, Grounds Anderson, LLC Hugh J. Barrett, Strategic Alliance Group Dr. Tom Biggs, Community Volunteer Michael F. Bloom, R.G. Miller Engineers, Inc. Jill Boullion, Greens Bayou Corridor Coalition Dick Cate, MCCM Architects Claire Caudill, Community Volunteer Allen B. Craig, Gardere, Wynne, Sewell Lee Forbes, Forbes Consultancy, PLLC Joanna Friesen, Community Volunteer Mike Garver, BRH-Garver Construction, L.P. Deborah Hartman, Deborah Hartman PR Colleen Holthouse, Community Volunteer Mike Howell, Howell Law Firm Lynne B. Johnson, Community Volunteer Tom Kartrude, Armand Bayou Nature Center Robert S. Lee, GSI Environmental Inc. Betty Leite, KBR Jennifer Lorenz, Bayou Land Conservancy Judy Meyer, John Daugherty Realtors Mike Mize, Community Volunteer Rebecca Olive, AECOM Bob Schwartz, Community Volunteer Lawrence Spence, Westside High School, HISD Cory Stull, Freese and Nichols, Inc. Merrie Talley, Talley Landscape Architects, Inc. Terri Thomas, Community Volunteer Matthew K. Zeve, IEA, Inc. Advisory Board Glenda Barrett, Community Volunteer John R. Bartos, Houston Canoe Club Judy Boyce, Jacob and Terese Hershey Foundation Jacqueline Buskop, Community Volunteer Glenda Callaway, Ekistics Corporation Mary Carter, Blackburn & Carter Karen Cornelius, Community Volunteer Tom Douglas, Community Volunteer Clayton Erikson, Community Volunteer Erik Eriksson, Port Of Houston Authority JoAnne Graham, Community Volunteer Don Greene, Whitewater Experience Susan Hill, Hawes Hill & Assoc. Tom Ivy, Community Volunteer John Jacob, Texas A&M Carla Knobloch, Community Volunteer Harriet Latimer, Development Consultant Jim Lester, Houston Advanced Research Center Carl Masterson, Community Volunteer Alisa Max, HC Watershed Protection Group Mickey Merritt, Texas Forest Service S. Reed Morian, DX Service Co. Paul Nelson, Lone Star Groundwater Conservation District Roksan Okan-Vick, Houston Parks Board Kathleen Ownby, SPARK School Park Program Mary Anne Piacentini, Katy Prairie Conservancy Rachel Powers, CEC Jim Pulliam, North Harris Co. Regional Water Auth. Commissioner Steve Radack, Harris County Todd Running, Houston-Galveston Area Council Kevin Shanley, The SWA Group Dick Smith, Cypress Creek Flood Control Coalition Melvin Spinks, CivilTech Engineering, Inc. Art Storey, HC Public Infrastructure Dept. Gary Struzick, Klotz Associates, Inc. Mike Talbott, HC Flood Control District Brittany Tones, Terracon Rico Torres, Bayou Shuttle Service LLC MaryAlice Torres-MacDonald, Texas Tech University Len Waterworth, Community Volunteer Carolyn White, HC Flood Control District Carla Wyatt, HC Flood Control District Watershed Representatives Tom Kartrude, Armand Bayou Bob Schwartz, Brays Bayou Mike Garver/ Anne Olson, Buffalo Bayou Linda Jones, Cedar Bayou Mike Mize, Clear Creek Jim Robertson, Cypress Creek Charriss York, Dickinson Bayou Jill Boullion, Greens Bayou Merrie Talley, Hunting Bayou Eileen Hatcher, Japhet Creek Becky Houston, Little White Oak Bayou Joanna Friesen/ Amy Sullivan, Sims Bayou Jennifer Lorenz, Spring Creek Tom Gall/ Bob Lee, White Oak Bayou June 16, 2014 Mr. Dwayne Johnson Regulatory Branch, CESWG-PE-RB U.S. Army Corps of Engineers P.O. Box 1229 Galveston, Texas 77553-1229 swg_public_notice@usace.army.mil Dear Mr. Johnson, The Bayou Preservation Association (BPA) submits this letter in support of the application of the Harris County Flood Control District (HCFCD) for approval of the Memorial Park Demonstration Project, USACE Permit Number: SWG-2012-01007. SUMMARY OF BPA COMMENT AND POSITION The BPA was founded in 1966, initially in opposition to a Corps of Engineers project to rectify Buffalo Bayou (Bayou) and line it with concrete. This opposition succeeded because of the tenacious efforts of BPA founders Terry Hershey and George Mitchell, and the intervention in Congress of then Congressman George H. W. Bush. Since that time, BPA has taken on the more general mission: “to protect and restore the richness and diversity of [Houston area] waterways through activism, advocacy, collaboration and education.” The BPA supports the permit application because it promises to serve the twin BPA goals of protection and restoration of Houston’s bayous. BPA considers the Memorial Park Demonstration Project (“Demonstration Project” or “Project”) to be particularly worthy of support because it is the first project of the Harris County Flood Control District (HCFCD) to incorporate fully the insights and principles of Natural Channel Design (NCD). For this reason, the Demonstration Project fulfils a long term interest and goal of the BPA and one of its founding directors, Terry Hershey, to test and demonstrate the benefits of NCD stream restoration techniques in the Houston environment. BPA’s support is not unconditional, however. Rather BPA welcomes careful public scrutiny of the Project and Project plan, and takes seriously all comments on the Project plan and design. BPA reserves the right to withdraw its support for the Project if evidence shows that the Project design and implementation departs substantially from NCD principles or if the Project cannot fulfil its protective and restoration goals and purposes. The Demonstration Project has engendered some criticism and controversy. This is understandable because the earthmoving aspects of construction are directly observable and appear destructive, however are necessary to correct the configuration of the channel so that it can be stable and support quality habitat. Also, waiting for the replanting and regrowth of vegetation to mature to high quality habitat takes significant time in human time scales. Erosion is highly destructive of trees and habitat, but operates on longer, gradual time scales, so the destruction goes unnoticed. The hydrology causing the erosion is very powerful and is not of natural origin but is rather the unintended product of urbanization and efforts to control flooding. Katharine C. Lord, Executive Director P.O. Box 131563 - Houston, TX 77219-1563 - Phone: 713.529.6443 - Fax: 713.529.6481 - email: bpa@hic.net www.bayoupreservation.org Bayou Preservation Association SWG-2012-01007 June 16, 2014 The destructive character of Buffalo Bayou’s unnatural hydrology can be seen in a series of aerial photographs going back to 1944 that are available on Google Earth. Attached are some of these photos plus a 1930 photo. The Public Notice states that the channel has moved three hundred fifty (350) feet since 1995 and destroyed more than an acre of land. However, the aerial photographs show that this migration of the channel has destroyed an entire oxbow of the Bayou, eliminating a much larger riparian forest. The images show also that the canopy of trees that covered Buffalo Bayou in 1930, 1944 and 1953 has disappeared as erosion has widened the channel. For BPA, evaluation of the Demonstration Project cannot and should not be framed as a simple comparison of the temporary effects of construction on trees, vegetation and habitat in the limited Project area. The proper frame of reference, rather, is to view the short-term negative effects of Project construction, which will be followed by replanting and regrowth, against the long-term benefits of eliminating the ongoing destruction to forest and habitat that will continue to occur if the proposed stream restoration project is not implemented. The processes and damage documented by the time series of aerial imagery is confirmed by what one sees on a canoe or kayak trip down the Bayou. All up and down the Bayou property owners have sought to armor their own stretch of bayou frontage with steel sheet piles, bags of concrete, timber walls, gabions, and giant heaps of rubble. This is understandable because people do what they think they need to do to protect their property. The problem with these fragmentary, band-aid solutions is that some hold up, at least for a time, but most fail, resulting in accelerated erosion and habitat degradation. Moreover, even when successful, one property owner’s solution simply shifts the energy of the Bayou to the opposite bank or to the downstream properties. The Public Notice notes that the bayou groups, including BPA and landowners that have encouraged HCFCD to do the Project, believe that amelioration of the damage to the Bayou and restoration to a more nearly natural and stable configuration requires a holistic approach to the Bayou channel and not piecemeal armoring. The Demonstration Project is intended to show how the channel of the Bayou can be stabilized to reduce erosion and protect property by showing due regard for, and making use of, the physics of river morphology. To accomplish this goal, the work to be performed will: 1) narrow and deepen the Bayou to a more stable, natural form; 2) re-align the channel to a stable, meandering plan form; 3) re-establish an adequately-wide floodplain down at the level of the Bayou banks; 4) incorporate natural bank stabilization components on the restored Bayou; and 5) re-vegetate the entire riparian corridor with native grasses, shrubs, and trees. River science is sufficiently advanced to allow hydrologists and engineers to identify the overall shape and configuration that the Bayou is working to achieve as it chews chaotically into the banks. In accordance with NCD principles, the Demonstration Project design will, indeed, re-sculpt the banks and central channel to achieve a plan-shape of the stream to allow the flow dynamics to promote and sustain a stable equilibrium consistent with the equilibrium the Bayou would itself achieve in geological time if left otherwise undisturbed. By making the adjustments at one time as a construction project, the transition will reduce endangerment of homes or other improvements along the way, and reduce the massive sediment loads the Bayou is presently carrying away from the banks as erosion. There is no question that the stream restoration work will be messy during construction. It is an exaggeration, however, to characterize the process of construction as a simple bulldozing of the riparian areas. This kind of stream restoration work attempts to use only the natural soils already in the bed of the stream. Structural support does not come from industrial materials, but from natural woody material along the outer bends and in the riffles, to help resist erosion right after construction, to help roughen the bend so that the higher energy, fast water is moved slightly away from the soil surface of the bank, and, importantly, to enrich the riparian habitat for small fish, reptiles and benthic creatures. Native trees and riparian vegetation are planted back along the banks, tight up against the outer bends so the root systems help secure the bank and so the shade Page 2 of 8 Bayou Preservation Association SWG-2012-01007 June 16, 2014 of the branches cools the pools, and planted further back from the banks on the sandbar side of the bend so that high flows can pass across the bar naturally. The Project contemplates re-planting of the Project area with native riparian plants and replacement of collected and stockpiled existing topsoil to support further the restoration process. If done properly, the Project area will quickly recover its lush riparian qualities, and will provide better habitat than is presently provided by a rapidly eroding and degraded stream system. BPA INTEREST AND ROLE IN THE DEMONSTRATION PROJECT BPA has been a supporter and catalyst in the origination and development of the Project. Over her many years of environmental activism, BPA founding director Terry Hershey became familiar with the work of Dr. Dave Rosgen, a hydrologist who developed Natural Channel Design. The Hershey Foundation has provided support for many years to BPA personnel and others to attend seminars conducted by Dr. Rosgen on NCD and related subjects. Ms. Hershey wished to apply Dr. Rosgen’s methods in Houston and made a restricted grant of funds to BPA that limited use of funds to “bayou protection or rectification in a manner demonstrated or recommended … by David Rosgen.” BPA used the grant to organize in November 2010 a workshop conducted by Dr. Rosgen. The Public Notice refers to this workshop as a beginning of Project planning, and further documents thirty-three (33) additional meetings and two (2) public hearings on the Project, many of which were organized or attended by BPA representatives. THE MORPHOLOGY OF BUFFALO BAYOU Natural Channel Design is a product of the scientific discipline of fluvial geomorphology. NCD is an evidencebased discipline that seeks to apply the insights of fluvial geomorphology to the improvement and restoration of streams that have been adversely affected by human influences and intervention. It is based on a stream classification system developed by Dr. Rosgen, and an understanding of these stream types and forms and their respective and relative stability or instability in nature. NCD stream restoration projects involve sculpting stream banks and channels and re-establishing an adequate floodplain at the level of stream so that the hydrological forces of the stream will promote the stability of the stream’s channel and banks to reduce erosion. Done properly, NCD stream restoration improves water quality and clarity, and improves habitat for aquatic species. NCD also emphasizes the planting of appropriate vegetation in riparian areas to promote bank stability and natural beauty. PROJECT NECESSITY The essential problem with Buffalo Bayou is the urbanization of the watershed that drains to it and the operation of the Addicks and Barker Reservoirs, both of which have dramatically altered the hydrologic conditions, referred to as “hydromodification,” that the Bayou has to exist in. Urbanization has utterly changed the response of the Buffalo Bayou watershed to rainfall events. In the language of river science, the speed with which rainfall in the watershed reaches the stream channel is called “time of concentration.” Today, the time of concentration for rainfall in the watershed below the Addicks and Barker Reservoirs is very rapid, and the Bayou exhibits rapid, flashy peak flows within a few hours after a storm event. By contrast, Buffalo Bayou’s channel configuration evolved in pre-development conditions in which the Bayou’s response to rainfall events was measured in days and weeks. With urbanization, the time of concentration of rainwater in Houston’s bayous is in most situations much faster than it was in natural conditions. In the upper Buffalo Bayou watershed, the time of concentration is much slower or non existent when held back by dams; however when later released from the dams, these flows impact the bayou downstream in a detrimental manner as described in the following paragraph. The rapid time of concentration follows directly from the replacement of grass and trees with roofs and pavement, and also traditional civil engineering which focused on the Page 3 of 8 Bayou Preservation Association SWG-2012-01007 June 16, 2014 installation of systems in urban areas intended to speed drainage. These changes have not merely caused a more rapid rise and fall inside the bayou channels; this also means that the more rapid concentration of storm water in Houston area bayous have higher peak flows– meaning higher floods. The flooding effects of urbanization are buffered somewhat in the Buffalo Bayou watershed because the Addicks and Barker Dams limit peak flow, but the pattern of rapidly rising flash-type storm drainage followed by rapid drops is well established. Moreover, the flow regime associated with USACE management of stormwater releases from the Addicks and Barker Reservoirs also contributes to further erosion by repeatedly inundating the bases or “toes” of the banks, limiting the ability of vegetation to become established at the interface of bank and channel. Well rooted vegetation at the toe promotes bank stability, but the cycle of rapid inundation and drying interferes, eventually leading to collapsing banks in many locations in Memorial Park. While observing the erosive nature of the stormwater releases from the Dams, we acknowledge that these controlled stormwater releases provide important flood protection. Implementation of this Project will allow this portion of the Bayou to adjust to the unfortunate and unintended side effects of these flood control devices. The key to a stable channel is connection of the channel to an adequate floodplain. In stable streams, at the critical depth where the banks would begin to fail, referred to as the “bankfull” depth, the stream flows have access to a floodplain where they spread out, reducing the velocities and eliminating any increase in depth in the channel flows. When the volumes and timing of flows change substantially, as has happened in Buffalo Bayou, a process called “downcutting” begins. As the depth in a stream increases, so do the shear stresses acting on the channel walls. If the channel becomes too deep, the maximum shear stresses (a function of depth, velocity and slope) on the channel bank toe will exceed the resistive capacity of the bank materials, causing toe erosion and leading to bank failure. In response to these alterations, Buffalo Bayou has eroded downward and outward and shifted its alignment in an attempt to create a new, stable stream and floodplain system. The stream is trying to find a new equilibrium with a stable channel and a sufficient floodplain to relieve erosive forces in the channel at high flows. A well-documented model of channel response to hydromodification was developed by Simon (1989) and is shown in Figure 1 (taken from the Federal Interagency Stream Restoration Working Group [FISRWG] 1998). Simon’s model was derived by studying stable streams that were channelized and oversized for drainage and flood control purposes and streams that were subjected to major hydromodification, such as Buffalo Bayou. In response to this hydromodification, six process-oriented stages of morphologic adjustment were observed. Driven by the natural tendency to re-establish dynamic equilibrium by the geomorphic processes, the streams downcut, widen, and then build a new stable channel with a bankfull floodplain bench at a new lower elevation. Data collected during the NCD assessment of the Project reach of Buffalo Bayou Page 4 of 8 Figure 1: Simon’s Model of Channel Response to Hydromodification Bayou Preservation Association SWG-2012-01007 June 16, 2014 indicates that the channel is in the Class IV (degradation/downcutting and widening) and Class V (aggradation/silting and widening) response stages at various locations along the Project reach. The goal is to get Buffalo Bayou to a new equilibrium with a sufficient floodplain, as represented by the Class VI (quasi equilibrium). One approach to the problem might be to let the Bayou progress to its new equilibrium (Class VI) on its own. The problem with that approach is that much of the channel and the riparian trees and vegetation will be destroyed in the process, along with the loss of valuable real estate, and excessive sediment loads to the bayou during the process. Further, the re-stabilization following Simon’s model in urban settings would take decades or centuries (consider that channel-forming/bankfull flows only occur 6 to 8 times per year in Houston). Some Project opponents propose that it is enough simply to add vegetation in the riparian corridor and apply bio-engineering techniques to the failing stream banks. This approach is merely a “green” approach to channel armoring, which has been shown to be ineffective at numerous properties along the bayou, as described above. The problem with armoring approaches is they do not reduce the erosive hydraulic energies in the stream that are causing the failures; they simply try to armor the banks against erosion, which is doomed to failure. Looking at Simon’s model (Figure 1), one can see that the initial problem occurs when the stream downcuts and loses its connection with an adequate floodplain at its natural, stable point, which is referred to as the “bankfull” channel elevation. The key component to channel stability of a channel in Class IV and V response stages is not addressed by any stand-alone form of channel armoring, bio-engineering, or vegetative plantings. Simon’s model shows that once a stream has downcut and lost access to its floodplain, it will continue downcutting, degrading, and aggrading until the point at which it can form a new, adequate floodplain at a lower elevation in the landscape, which will then allow for the stream to stabilize. The goal of the Project is to skip the random and lengthy destructive steps of the channel response process and to restore the channel to a new, stable stream channel and floodplain that is in equilibrium with current watershed conditions through a single, fully-restorative step. THE CHANNEL OF BUFFALO BAYOU IN THE VICINITY OF MEMORIAL PARK HAS BECOME WIDER AND STRAIGHTER OVER TIME Any member of the public who wants to see the dramatic changes in the Buffalo Bayou channel between Memorial Park and the River Oaks Country Club (ROCC) should examine the time series of aerial photos of the channel available on Google Earth. Attached are some of these photos. These sets of images are available from 1944 to February of this year. A photo from 1930 is also attached. Comparison of these images over time shows very dramatic erosion and changes of channel configuration as the Bayou is progressing through the steps of channel response to hydromodification described by Simon (Figure 1), as discussed above. The following discussion addresses two particular locations. First is a forested location between River Oaks Country Club, the Bayou channel and Memorial Park that has essentially disappeared, destroying acres of forest. Second is a location at the Hogg Bird Sanctuary at the downstream end of the Project zone where the changing dynamics of the Bayou appear to be leading to potential loss of a portion of the Hogg Bird Sanctuary. The Disappearing “S”. The Google Earth aerial images of the Project area have images from 1944, 1953, 1978, 1989, 1991, 1995 and numerous sets at shorter intervals from 2002 to the present. The early images (1930, 1944, 1953 and 1978) show a substantial forested tract of land between the River Oaks Golf Course Page 5 of 8 Bayou Preservation Association SWG-2012-01007 June 16, 2014 and the Buffalo Bayou channel in the vicinity of the Parks Department maintenance facilities in the eastern part of Memorial Park and the park boundary at Crestwood Street. The Bayou channel in the 1944 and 1953 image sets show a gently curving “S” shape defining a pair of oxbows. At the southerly curve of the “S” the bayou flows in an east-southeasterly direction adjacent to ROCC, then makes a wide loop to flow in a nearly opposite northwesterly direction, then completes the top of the “S” with a wide loop to flow east again. From the top of the “S,” the channel curves gently to a southeasterly flow along Crestwood Street. In these early images, the land on the ROCC side in the oxbow has the appearance of a heavily wooded “peninsula" buffering the ROCC and Memorial Park. This “peninsula” in the top of the “S” remains largely intact from 1930 to 2002, but gradual erosion is apparent. Accompanying this erosion is a consistent widening of the channel as the years pass. A riparian canopy of forest foliage covers most of the bayou channel in the 1930, 1944 and 1953 images, but has mainly disappeared since then. The shape of this “peninsula” remains recognizable into the 2000s, but the 1995 images are the last in which the tip remains forested. In the 2002 images, the tip of the former “peninsula” between the ROCC, the Bayou and Memorial Park has been shaven down considerably, and the trees at what remains of the tip of the “peninsula” have largely disappeared. What appears in its place in the 2002 image is a much wider channel, ponding zone and shallows where the curve of the upper part of the “S” was in 1944. The pattern of erosion, loss of riparian canopy and widening of the Bayou channel is evident in the 1944-1995 period, but gradual. Since 1995, the erosion of the former “peninsula” seems to have sped up, and the upper part of the “S” has completely disappeared. In images made between 2002 and 2008, the “peninsula” continues its retreat, but by 2008 sediment has accreted and filled the 1944 and 1953 channel. Images taken in 2014 show that the land that was once a large, wooded “peninsula” on the ROCC side is now an alluvial grassland on the Memorial Park side of Buffalo Bayou. The whole loop that defined the upper part of the “S” is now essentially a straight line flowing almost due north and then bends sharply back to follow the curve along Crestwood Street. This detailed discussion is useful because the part of the Project Plan that has generated the most controversy provides for cutting a curved channel through this angle and reconfiguring the south bank into an “S” shape again. If the 1944 Bayou looked like a capital “S” from the air, then after Project completion, this part of the bayou will look like a hybrid, slightly tilted “S” that is a capital letter at the bottom, and a small “s” at that top. It is very understandable that this kind of geoengineering is jarring to a casual, nature-loving observer. If one canoes the Bayou today, the narrow strip of land that remains has shrubbery and trees and looks nice. The alluvial grassland is also nice and green. However, on the Memorial Park side just past the newly formed bend, there is a nearly vertical, highly eroded bank that is on the receiving end of the strong currents that continue to erode the channel and banks. This bank on the Memorial Park side will continue to erode very rapidly under current conditions as the Bayou progresses through down cutting, degradation, and aggradation as it tries to achieve a new equilibrium, as discussed above. Moreover, the hydrological forces that have destroyed the upper half of the “S” are unchanged. By a chaotic process of uncertain duration, Buffalo Bayou will erode away all that remains of the former oxbow. The channel realignment that some object to will remove a portion of the remaining buffer, but in a way that stabilizes the channel to reduce the erosive forces. The Bayou Channel Appears Poised to Claim a Substantial Portion of the Hogg Bird Sanctuary. Examination of the Google Earth images shows that the Buffalo Bayou channel is very close to destroying a portion of the Hogg Bird Sanctuary. In contrast to the relatively long-term (human time scale, instantaneous in geological time frames) destruction of the big “S” described above, the Bayou channel appears ready to jump north and claim the channel of a small tributary in the Hogg Bird Sanctuary. This risk is quite apparent in the Page 6 of 8 Bayou Preservation Association SWG-2012-01007 June 16, 2014 most recent aerial images taken in February, 2014, where the barrier between the main channel and the tributary is almost gone. IMPACT OF PROJECT ON TREES AND UNDERSTORY As noted above, some commentary from Project opponents suggests that the intention of the Project planners is to “bulldoze” the banks of the Bayou in the Project area. This suggests that all trees in the Project area will be destroyed. This is untrue. The danger of tree removal is in the “cut and fill” zones. These are the areas where banks will be re-shaped to a stable stream form with an adequate floodplain bench. The planners of the Project have advised BPA that 972 trees were identified in the Project area: 73 dead and 899 living, 391 on public property and 581 on private property. The “cut and fill” zones are approximately 30% of the total reach of the Project, placing approximately 180 living trees at risk of removal. BPA has been advised by the Project planners that no general clear-cutting of these trees is planned. The intent is rather to assess each tree on a case by case basis during construction with a view to the quality of each individual tree and how each fits into the plan of replanting. This assessment involves issues such as whether an individual tree is a native or invasive, exotic species, how it contributes to forest canopy, the health of the tree and its location. It is well to note also that the largest number of trees at risk are on the portion of River Oaks Country Club property that has already been severely eroded as discussed above and continues to be subject to the most severe erosive forces in the whole Project area. COMMENTS ON PUBLICITY CONCERNING THE PROJECT As planning and design work on the Project has progressed, the Project has been the subject of increasing public comment. Public concern is natural and to be expected. BPA was founded as an ad hoc group opposing plans to concrete line Buffalo Bayou. Traditional civil engineering approaches to flooding and drainage issues were focused on speeding drainage, which meant straightening bayous and transforming the natural channels into concrete ditches. In the decades since the formation of the Harris County Flood Control District in 1935 and the major infrastructure construction projects of the USACE in the 1940s and 1950s, flooding solutions based on the use of concrete, levees and rectification have lost favor with both the public and the civil engineering community. The research and work of river scientists such as Dr. Dave Rosgen have brought a deeper understanding of the risks and unintended consequences associated with interventions in river systems, and the changes to river hydrology and dynamics resulting from long term human influences associated with urbanization, deforestation, grassland destruction and the like. Gains in scientific knowledge and increasing public appreciation of the beauty and importance of natural streams, associated riparian greenspaces and wildlife habitat have placed a heavy burden on any project involving substantial earthmoving and construction. A key issue in evaluation of the Project involves one’s initial understanding of whether the reaches of Buffalo Bayou in the Project are in a “natural” condition. What is or isn’t “natural” means different things to different people. Additional differences of opinion may arise based on whether specific attributes of the natural environment are viewed up close or from a broader perspective. If one’s preferred rule of the protection of nature in the project area says that not a single tree may be removed, nor should a single shovel be permitted to dig in riparian areas, then nothing smacking of engineering is permissible. If consistently applied, the naturalist following such a rule may be compelled to classify the changes in Buffalo Bayou’s channel that have occurred as a result of urbanization as “natural” as well, since the hydrological forces causing the changes are Page 7 of 8 Bayou Preservation Association SWG-2012-01007 June 16, 2014 largely impersonal and not the product of human intention, though caused by human urbanization of the watershed. As discussed above, the effects of urbanization have produced an unnatural flow of water. The Bayou will adjust to these changes and become stable over a long period of time as discussed above. Some project opponents point out recent re-growth of trees and riparian vegetation along eroded stretches of the Bayou. This vegetation is dominated by fast-growing, opportunistic and emergent species (including some invasive, exotic species). These should not be confused with the slow-growing species associated with a stable floodplain and riparian corridor. In fact, many of these opportunistic and emergent species prevent the growth of the more suitable and desirable species. The BPA approaches the issues surrounding the Project from the standpoint of stewardship of the portions of environment entrusted to Houston area communities. Buffalo Bayou is unique from this perspective because the watershed that it drains is almost entirely within Harris County and primarily within Houston’s city limits. This is not a situation involving a longer river where upstream and downstream communities have different interests. River science teaches that natural river systems seek and generally achieve what fluvial geomorphologists call “dynamic equilibrium,” but the process of achieving that equilibrium occurs on geological time scales far longer than individual human lives. Buffalo Bayou may seem quiet and “natural” to those of us who hike, canoe and picnic there, but on a geological time scale the changes documented in sixty (60) years of aerial photography are rapid indeed. On a geological time scale, the Buffalo Bayou channel in the Project area is snaking about like a high pressure water hose left untended on the ground. CONCLUSION BPA supports the Project because it believes that the scientific, design and engineering principles underlying Natural Channel Design are sufficiently robust, well-defined and understood to justify going forward with the Project. It is still a young discipline, and the Project is indeed, a Demonstration Project, but not a test or experiment. There is risk, not associated with the river science itself, but with such events as a catastrophic rain event just after project completion. BPA shares the values of the environmental community and recognizes the fear and mistrust that a large project of this type arouses but believes that the balance of risk and reward justifies the Project. The public-private partnership of HCFCD, the City of Houston and the River Oaks Country Club presents a unique opportunity to improve public stewardship of Buffalo Bayou, and should be embraced for this reason. If there are questions on this set of comments, please contact Mr. Steve Hupp, M.S., BPA Water Quality Director at 713-529-6443, or by email at: shupp@bayoupreservation.org. Robert Rayburn J. Tynan Kelly Jack Sakolosky Steve Hupp President Past President Vice President Water Quality Director Attachment – 10 slides Page 8 of 8 Channel Migration 1930 Channel Migration 1944 Channel Migration 1953 Channel Migration 1964 Channel Migration 1981 Channel Migration 1999 Channel Migration 2010 Channel Migration 1930-1964 Channel Migration 1981-2010 Channel Migration 1916 - 2010 14-0620 Cypress Creek Flood Control Coalition Letter of Support 14-0623 Bob Lee USACE _MPDP_Comment_RSLO62314R 14-0625 BBP Letter of Support 14-0630 SN 22_MPDP_Stat To: Mr. Dwayne Johnson Regulatory Branch, CESWG-PE-RB U.S. Army Corps of Engineers P.O. Box 1229 Galveston, Texas 77553-1229 June 30, 2014 Re: Memorial Park Demonstration Project, USACE Permit Number:SWG-2012-01007 The footprint of the Washington Avenue Coalition / Memorial Park Superneighborhood (SN22) is defined by Buffalo Bayou to the south, White Oak Bayou to the north, and it includes Memorial Park. The health and preservation of both the park and the bayous are of great concern to SN22’s residents. Of the SN22 Council membership, comprised of representatives from our constituent neighborhoods, many have attended MPDP public meetings, reviewed materials presented, and heard presentations and comments from those both favoring and opposing this demonstration project. We recognize that there is a critical need to stabilize the bayou banks to prevent continued loss of property, and support a coordinated effort to lessen the impacts of erosion rather than continuing the individual and haphazard approach that has been occurring unsuccessfully through the years. We also recognize that as development continues to densify throughout the watershed without providing sufficient runoff mitigation, our natural waterways will be increasingly stressed by heavier storm water flow volumes. The MPDP takes a context sensitive and environmentally appropriate approach toward resolving these issues, and attempts to apply the best scientific stream restoration practices to this short bayou segment that has been experiencing rapid change. We do request that full evaluation of any revised drainage capacity be initiated to assure that adjacent neighborhoods in the watershed are not subject to increased risk of flooding. Additionally, we would encourage adequate follow-up to evaluate the success of the project to assure that reduction in erosion, re-growth of the riparian and upland native vegetation, reestablishment of wildlife habitat, and improvement to downstream water quality occur as anticipated. Bayou Preservation Association, in conjunction with Harris County Flood Control District, is knowledgable about the functional needs of this waterway, has been thorough in making the public aware of the project details, and should be trusted to act in the best interest of the bayou’s protection. It is imperative that a solution be found that will allow a natural Buffalo Bayou to co-exist within, and effectively serve, this increasingly urbanized watershed. The SN22 Council supports the Memorial Park Demonstration Project as a viable first step toward achieving that goal. Thank you for your consideration of our comments, Tom Dornbusch Superneighborhood 22 Council President