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Archive for the ‘river restoration’ Category

Back in the 1970’s and 1980’s, the U.S. Army Corps of Engineers had the foresight to know the value inherent in floodplains. Consequently, over the course of several years, this agency went about purchasing floodplain land in the Charles River watershed. The Army Corps coined the term “Natural Valley Storage Areas” (NVSA’s) which is indeed what intact and functional floodplains do. The homepage for this project can be viewed here.

Fast forward to 2017 to when the Army Corps presented their Draft Master Plan for the project to the public. The Corps conducted an economic analysis of the benefits of these storage areas. The estimated prevented losses from flood damages was almost $12 million in unadjusted dollars. The Corps also estimated the economic benefits of visitors and recreation between $3.2 an $4.6 million.  Based on this analysis, one could say the natural capital in these areas protected areas is at least $15 million.

At the public meeting,  the Army Corps presented the hydrograph for the 2010 floods in late March and early April. As soon as I saw the data, I was reminded of the Otter Creek analysis I had written about.  My only problem with the analysis that the Army Corps presented, was that the discharge was not normalized by drainage area.  After obtaining the data from the gauges in Dover, MA and  Medway, MA, the story appeared to be pretty similar to Otter Creek’s.

The data show that for the upstream gauge in Medway, the peak unit discharge was 26.8 cubic feet per second (cfs) per square mile (csm) on March 31, 2010. Note how much more rapid the rising limb of the Medway unit hydrograph is compared to the Dover gauge.  On April 1st and 2nd the Medway runoff is receding, whereas the Dover runoff is still increasing, albeit at a slow rate.  The peak discharge in Dover occurs on April 2nd, but only at a unit runoff of only 15 csm.  Just as with the Otter Creek analysis, we can do a ‘what if’ analysis and simply assume that Dover had very similar unit runoff as Medway. Under this hypothetical scenario, Dover could have experienced a discharge of just over 4,900 cfs (26.8 csm X 183 square miles).  Fortunately, the peak mean daily discharge at the Dover gauge was 2,760 cfs, which is 56% of the theoretical peak, had the same unit runoff occurred throughout the watershed.  The two USGS gauges and the Natural Valley Storage Areas can be seen in this ArcGIS Online presentation slide.

A cursory review of the NVSA’s indicate that while floodwaters can and indeed are stored, it would be perhaps a bit too generous to attribute all of the flood attenuation between Medway and Dover to these areas. The 8,095 acres of storage area converts to 12.6 square miles, or roughly 6.9% of the Dover gauge’s watershed area.  In addition, at only 65 square miles, one would expect a certain amount of flashiness (i.e. rapidly increasing and decreasing flows) at the Medford gauge.  Nevertheless, as a thought experiment,  had the Natural Valley  Storage Areas been developed and the percent impervious area dramatically increased in these areas, one could safely assume that  the Dover gauge would very likely have seen a unit discharge higher than 15 csm.  The NVSA’s do provide important floodwater storage and the Army Corps analysis does indeed indicate a diminution in flood damages.

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Author’s note: I just wrapped up a course on Coursera titled “Innovative Finance: Hacking finance to change the world.” Aunnie Patton Power and Tsakane Ngoepe from the University of Cape Town taught the course. They taught me a great deal. I very much enjoyed the content that they developed as well as solicited. Over the 5-week course, I completed weekly assignments. The text below is my submission for the final assignment in Week 5. In addition to this course, I’ve also found Blue Forest Conservation’s work very inspiring. While there are some differences in the forest resilience bond and the flood resilience bond, they are minor. (I’ve heard that imitation is the sincerest form of flattery.) In short, I’m very grateful for the work of others in helping me shape some ideas about finding alternative financing mechanisms to fund floodplain restoration work.

 

ISSUE AREA AND THE OUTCOMES IDENTIFIED

Inland flooding is a massive problem around the world. In the US, the Federal Emergency Management Agency (FEMA) has developed the National Flood Insurance Program (NFIP). Several large storms have put this agency severely in debt to an amount that exceeds $30 billion. This bankrupt program would benefit greatly from private capital working to reduce flood risk. In addition, many rivers have been cut off from their floodplains due to development, river incision due to poor upstream land management and levees. In these cases, several ecosystem services are degraded. Runoff tends to be flashier which leads to worsened flood conditions downstream and summer low flows tend to be lower. Other degraded ecosystem services can also include lower water quality, higher water temperatures, and degraded fish habitat.

A flood resilience bond seeks a win-win-win outcome. The first win is for the investor that gains a market rate return on their investment. The second winner are the multi-stakeholders who finance the bond with monthly cashflow payments. These entities are insurance agencies, water suppliers and hydropower operators who have been able to price out the benefit of the floodplain restoration project through various modeling exercises. Finally, the ecosystem benefits because a restored and intact river floodplain has been created.

CHALLENGES IDENTIFIED THAT THIS DESIGN ADDRESSES

Determining the value of the floodplain restoration will be extremely challenging. Stakeholders will be presented with a brand-new idea. The value of the restoration will need to exceed the cost of the monthly cash flow payments. The forest resilience bond that Blue Forest Conservation has developed is an innovative financing tool that really is a ground-breaking idea. The flood resilience bond is designed in many ways to mimic this bond.

This idea will only work if a significantly large enough area of floodplain can be restored. In other words, if the project only connects an extra acre or two of floodplain, then very little measurable benefits for the Phase 2 cash flow providing stakeholders will accrue. The GIS screening tool really is a cherry-picking exercise where sizable chunks of land can be set aside to flood when a flood does occur.

Landowners that are in the floodplain likely won’t be thrilled about hearing that their land will be flooded more often. They might need to be compensated.

Any investor that might invest in the bond will be doing due diligence. The bond must have rock solid numbers, risk assessment and contracted cash flow that make the deal even worth the time of the investor taking the time to look at the deal.

Ultimately, this design starts to address the disastrous debt that FEMA has accrued in its NFIP by lowering flood risk at no cost to FEMA and it provides private capital to fund river restoration.

RESOURCES I’VE IDENTIFIED THAT THIS DESIGN USESS

As an individual with an idea, I need foundation money to back this initial idea. A partner such as the Rockefeller Foundation would be ideal as they have backed Blue Forest Conservation and they have excellent contacts with banks and modelling firms. Given their understanding of the challenges and structure of the forest resilience bond, they would have valuable insight.

Phase 1 funding would also go to catastrophe modeling firms such as AIR Worldwide or RMS. They could look at flood scenarios before and after the floodplain restoration project and determine the savings in claims payment for insurance companies that have policy holders downstream of the project.

Phase 1 funding would also go to either a firm such as ESRI, or it could go to a university geography department. The purpose would be to develop a screening tool to identify potential floodplain restoration sites that are large enough for benefits to be accrued.

Phase 1 funding would also go to a bank capable of structuring the bond. The bank would provide the legal and financial expertise to vet the idea and identify potential funders.

Phase 1 could also involve a land trust or environmental NGO that might be interested in obtaining or managing the restored floodplain land.

Phase 2 would be to develop a flood resilience bond. Outside investors would put real money into the bond with expectation of a return on their investment. The stakeholders that are benefiting from the restoration project would be providing contracted cash flow into the special purpose vehicle. These stakeholders would include insurance companies selling flood insurance policies, hydropower operators benefiting from higher summer baseflows and water suppliers also benefiting from higher summer baseflows.

THE OPPORTUNITIES AROUND BUSINESS MODEL INNOVATION, MULTI-STAKEHOLDER PARTNERSHIPS AND FINANCING STRUCTURES THAT I’VE IDENTIFIED

The project would be outcome based. Measurable improvements in flood claim reduction and increased baseflow must be demonstrated.

The flood resilience bond involves multi-stakeholders in Phase 1 and Phase 2.

Floodplain restoration has typically been publicly funded. Private financing of restoration is a new and exciting idea. Private capital could change FEMA policy through the value creation in floodplain restoration.

NEXT STEPS TO PILOT MY DESIGN

I’m an individual with an idea and a love of rivers. I could approach the Rockefeller Foundation or the Hewlett Foundation and pitch them the idea. I could have conversations with ESRI or geography departments to develop a screening tool. Foundation backing with money in hand will allow me to approach modeling firms to spend time on their analysis.

 




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If you are a member of LinkedIn and you are interested in stream and river restoration, I recommend joining the ASCE River Restoration TC group.  Over the years, there have been some great discussions swirling around restoration. Doug Shields recently posted this question:

“How do you design a stream channel for a project that includes channel reconstruction/reconfiguration?” The responses so far have been quite good and I look forward to reading more. Jim MacBroom was my former boss and his opening sentence is perfect: “The most important step is to have a clear understanding of the channel’s physical processes and how they relate to the project’s goals and objectives.” Clear, articulate and difficult to argue otherwise.

 

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I don’t use this blog too much for advocacy, but on March 1, 2016 the EPA and USGS released a draft report whereby public input is being solicited. Have a read and let your scientific expertise on ecology, hydrology and anthropomorphic alterations to flow be heard:

http://www.regulations.gov/#!docketDetail;D=EPA-HQ-OW-2015-0335

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Wendi Goldsmith is the CEO of the Bioengineering Group and has recently published a book, Bioengineering Case Studies with some her colleagues through Springer.  This book includes a number of case studies and highlights several stream bank slope stabilization techniques whereby best practice techniques were used.

The release of this book is timely as this past fall, the Army Corps of Engineers Hydrologic Engineering Center announced in its Fall 2013 newsletter that the bank stability analysis model, BSTEM, will be incorporated into HEC-RAS.  One aspect of BSTEM that sounds intriguing is that it can compare factor of safety values for existing conditions and banks that have been subjected to stabilization methods. Until now, HEC-RAS has only been able to assess scour/incision vertically. With the incorporation of BSTEM, it seems as though lateral erosion can be modeled as well.

Another worthwhile read recently released is the MA Department of Fish & Game Division of Ecological Restoration’s 2013 Annual Report which is focused on the value of restoration and is available as a pdf here.

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Dr. Andrew Simon pulls together an excellent set of ideas in this presentation:

http://www.eng.buffalo.edu/glp/events/summer2008/week1/full/16-ResponseAndRestorationImplications.pdf

For several years, I’ve struggled with the idea of a reference stream. He lays out some of the problems with the approach.  I like how he introduces the idea of a hydrologic floodplain and a topographic floodplain.  I also like how he highlights the notion that “bankfull” discharge applies to a stable channel.

One of the best questions he asks is: “How does the channel respond?” Answer: “It depends”  The figure below was pulled from Janet Hooke’s 2003 Geomorphology article titled “Coarse sediment connectivity in river channel systems: a conceptual framework methodology”  I think the image does a good job of supporting Dr. Simons’ question about how a channel would respond. Clearly the spatial variability that all rivers have dictate that a thorough inspection of a site and its context within a watershed is warranted.

erosion_deposition_spatial_variability

I also always like a presentation that goes back and explicitly states first principals in geomorphology:

Applied (Driving) Forces vs. Resisting Forces.

I was first exposed to this idea as an undergraduate at Middlebury College in the early 1990’s thanks to my advisor Jack Schmidt and it is still true as it ever was today.

I like the way Mr. Simon thinks and presents his ideas. Keeping these ideas in mind the next time a restoration project comes along would be excellent, especially at the early stages so that that all parties can better understand the river adjustment dynamics at a project site.

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Chalk one up for the American Geophysical Union (AGU). They have compiled 28 papers and assembled them in one book, and made each paper available in a downloadable pdf file.

Stream Restoration in Dynamic Fluvial Systems: Scientific Approaches, Analyses, and Tools
http://www.agu.org/books/gm/v194/

Despite this book’s release in 2011, I just ran across this. As such, I haven’t read much yet, but I now know what some of my night time reading will entail for the next few weeks.

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