On November 21, 2022, the U.S. Government filed a 70-page motion for a summary judgment in the Addicks-Barker Downstream Cases. In 2020, Judge Loren A. Smith dismissed the downstream cases, ruling that the plaintiffs had no right to sue the government for “taking” their property in what he called a 2,000-year storm. However, in June 2022, a federal appeals court reversed Judge Loren’s decision, re-opening the case. The appeals court ruled on a number of procedural issues and remanded the case back to Loren’s court for further consideration.
Both appellants and the government had urged the appeals court to order a summary judgment. But the appeals court declined. It noted that “due to the fact-intensive nature of takings cases, summary judgment should not be granted precipitously.”
In summary, the government contends that the Addicks and Barker dams:
Historically prevented far more damage ($16.5 billion through 2016) than the release of water during Harvey caused
Reduced plaintiff’s level of flooding by up to 7-8 feet
Did not “cause” – in a legal sense – the plaintiffs’ flooding
Further, the government contends that plaintiffs’ claims are based on a single, extraordinary, catastrophic event and any action undertaken by the Corps during the event does not constitute a “taking” under the Fifth Amendment.
Dams Modified in Response to Downstream Development
The original design from the 1930s included a downstream channel with a capacity of approximately 18,000 cubic feet per second (CFS), and 4 ungated and 1 gated outlets on each dam. They permitted a combined, uncontrolled discharge of floodwater into Buffalo Bayou of approximately 15,700 cfs.
In 1948, the Corps constructed gates on two additional conduits on each dam so that three of the five conduits were gated. This design reduced the combined uncontrolled discharge into Buffalo Bayou to approximately 7,900 cfs, which was considered at that time to be the capacity of that channel.
“However, increasing urban development along Buffalo Bayou in the 1940s and 1950s created a potential flood threat from uncontrolled releases at that level,” says the motion.
The Corps then added gates to additional conduits in the early 1960s to provide more protection to developing downstream areas. With all conduits gated, “[t]he total of all releases, plus local runoff downstream of the dams, would start at 4,000 cfs and be gradually increased to 6,000 cfs except under emergency conditions.”
Later, the motion states, “Continued residential development along Buffalo Bayou downstream of the reservoirs resulted in channel encroachment and by late 1970, water flows in excess of 3,000 cfs in the unimproved channel below the dams would begin to threaten the first floor elevations of some residences, and release rates of 2,500 to 2,800 cfs would produce nuisance type flooding of flower beds, trees and lawns in some areas along Buffalo Bayou and its tributaries.”
Causation Argument
Plaintiffs claimed that the opening of the dams’ gates during Harvey caused their flooding. But the government argues that the plaintiffs must demonstrate what would have happened if the government had not acted at all. In other words, the government argues that “causation” must be “based on the entirety of government actions.” See Page 26. That includes construction of the dams! And without them, the government says on Page 42, “properties along Buffalo Bayou would have experienced much greater flooding.”
“Plaintiffs have not alleged—let alone identified any evidence to prove—that their properties experienced more flooding than they would have experienced if the Corps had never constructed the Project, their claims fail,” the government argues.
Doctrine of Relative Benefits
The government also invokes a legal principle called the “relative benefits doctrine.” Under the relative benefits doctrine, “[e]ven if a causal relationship exists between the Government’s action and plaintiff’s damage . . . no liability attaches if the Government’s conduct bestowed more benefit than detriment on plaintiff’s property.”
The motion then alleges that the benefits to downstream properties far outweigh the Harvey-related damages. A 2016 study the government quotes alleges the dams reduced/avoided damages to downstream properties by $16.5 billion. That total is updated annually and based on a with/without the dams comparison.
Comparison of Peak Inflows/Outflows
The government motion cites the following statistics of the two reservoirs during Harvey:
Addicks peak inflow: 70,000 cfs
Addicks peak release: 6,500 cfs or 9.3% of the peak inflow.
Barker peak inflow: 77,000 cfs,
Barker peak outflow: 4,821 cfs or 6.3% of the peak inflow.
Peak flow rates downstream along Buffalo Bayou ranged from 13,800 cfs to 36,400 cfs. The government alleges that at those levels, plaintiffs properties would flooded regardless of discharge from the dams. The government also alleges that without the dams, flooding in Piney Point would have been 7 to 8 feet higher.
The Corps calculated after Harvey that the dams prevented 30,000 structures from flooding.
In this section of the motion, government lawyers point out that plaintiffs’ properties would have flooded in previous floods such as Tax Day and Memorial Day had it not been for the dams.
What Constitutes a Taking?
In conclusion, the government argues that the flooding during Harvey did not constitute a “taking” under the Fifth Amendment.
It was not intended.
It resulted from an extreme hurricane with unprecedented rainfall.
The government’s role in any flooding of downstream properties was secondary to the severe rainfall.
The dams were designed and built decades before the plaintiffs’ properties.
Releases during Harvey were designed to protect the integrity of the dam.
Flooding of plaintiffs’ property is not frequent enough to rise to the level of a taking.
The failure of government to take certain actions alleged by plaintiffs would constitute a tort a most, not a taking.
A tort is a failure to take action that results in damage to someone.
I will let you know how the plaintiffs’ lawyers respond later this month.
Posted by Bob Rehak on 1/1/2023
1951 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2022/05/20210520-RJR_6640.jpg?fit=1200%2C725&ssl=17251200adminadmin2023-01-01 14:12:402023-01-01 14:22:49Government Again Moves for Summary Judgment In Addicks-Barker Downstream Cases
Data provided by the National Weather Service (NWS) shows that precipitation appears to be increasing with temperature in Houston and Harris County. A reader recently asked whether there was a correlation. The hypothesis: in this climate, if temperature increases, then so will evaporation and rainfall. Eighty to 130 years worth of data at different locations show both variables trending up. But most scientists would consider the coefficient of correlation weak to non-existent.
Behind the Theory
The theory is plausible from several perspectives.
Warm air holds more moisture than cool air. Warm air also rises. As it cools at higher altitudes, precipitation forms. Think “afternoon thunderstorms on hot summer days.”
Precipitation also forms when warm and cool fronts collide.
It often forms when warm moisture-laden air streams in from the Gulf.
Hurricanes form in the hottest parts of the year.
Distribution of hurricanes by month during the last 100 years.
But the question concerned correlation, not causation.
Other outside factors could reduce precipitation, such as droughts triggered by changes in Pacific Ocean currents. Those who remember the drought from 2011 to 2014 may also remember how hot it was.
But looking at 80 to 130 years of data highlights long-term climate trends. That “evens out” the influence of individual events.
Qualifiers
NWS plotted all available historical data for precipitation and temperature on line graphs and then superimposed trend lines. The graphs show official data from two sources: Houston-Hobby Airport and the “City of Houston.”
I put City of Houston in quotes because the the official City-of-Houston data is currently collected at Bush Intercontinental Airport. But the location has bounced around. So the “City” isn’t one location, but many:
Cotton Station (July 1881 – September 1909)
Stewart Building at Preston and Fannin (September 1909 – February 1926)
Shell Building at Texas and Fannin (March 1926 – August 1938)
Federal Building at Franklin and Fannin (August 1938 – May 1969)
Intercontinental Airport (June 1969 – Present)
We have less data for Houston-Hobby because Hobby Airport didn’t exist until 1927. That’s when someone turned a 600-acre pasture into a landing field. The City of Houston purchased the field in 1937 and expanded it.
With those qualifiers, see the charts below. Both temperature and rainfall vary from year to year. But rainfall shows extreme variance. Regardless, in all four graphs the trend lines slowly increase.
Houston-Hobby Airport
Mean temps at Hobby increased from 69 to 73 degrees – a 4 degree increase between 1931 and 2022.During roughly the same time period, precipitation increased approximately 9 inches from about 48 to 57 inches.Also notice the extreme range – from less than 30 to more than 80 inches.
City of Houston Data
The City of Houston data covers a wider time period. Within that, the location varied as noted above. The big jump was from downtown to Bush Intercontinental Airport in 1969. Generally speaking, as you go farther north from the coast, precipitation decreases. But the difference is less than an inch. Atlas 14 shows that a 100-year, 24-hour storm is 17.6 inches at Hobby, 17 inches downtown, and 16.9 inches at Intercontinental.
City data indicates mean temp has increased roughly 4 degrees in last 120 years.During roughly the same years, precipitation increased about 5-6 inches. Here, the range was even more extreme. From less than 20 inches to 80 – a 4X difference.
So the change in where the City collects official data actually worked against the hypothesis. And it shows.
Summary of Trend Differences
Summarizing the key differences:
As the temp trend line increased 4 degrees at Hobby, precipitation increased 9 inches.
As temp increased 4 degrees at various City locations, precipitation increased 6 inches.
Low Coefficient of Correlation
Jimmy Fowler of the National Weather Service’s Houston/Galveston office calculated the coefficients of correlation between the two series of data at each location.
For Hobby, the coefficient of correlation is only .03. The City’s is slightly higher at .11.
Jimmy Fowler, Meteorologist, National Weather Service
For those who didn’t study statistics in college, the coefficient of correlation tells you how much one variable changes in response to another.
A perfect positive correlation is 1.0. Example: population growth and food consumption.
A perfect negative correlation is -1. Example: hours worked and free time.
In both cases, one unit of change in the first variable accounts for an equal unit of change in the second. But most correlations fall between the two extremes with different degrees of strength.
The chart below indicates how scientists would characterize correlation coefficients of .03 and .11. Both are considered “very weak” or having “no association.”
So, if the trends are all up, why is the co-efficient of correlation so low? Part of the answer has to do with those R2 (R squared) values you see at the bottom of the charts. They show the data doesn’t conform to the trend lines very well. Temperature fits moderately well. But precipitation shows extreme variance.
A perfect fit (1.0) would show all the data points on the line. As a rule of thumb, 0.8 (80%) or higher is considered a good fit. But the R2 values in these trend lines range from 0.03 to 0.5.
Conclusion
You can read into this data whatever you want depending on your point of view. Climate change advocates might see proof in the consistent slope of the trend lines that warming temperatures and more precipitation are related. A deeper dig into the data reveals the correlation is weak at best and possibly non-existent. Other factors may be at play and influencing the data.
To demonstrate causation, you need to show a directional relationship with no alternative explanations. But with weather, you have a multitude of alternative explanations.
Remember that weather is global and that we looked only at Houston in this instance.
However, a friend who traded weather-related derivatives before retirement tracked hundreds of temperature sites. He found they all trended warmer over time. But he believed the variance resulted primarily from changes in surrounding ground cover, i.e., replacement of natural ground cover with concrete – also known as the urban heat island effect.
He also tracked variance to changes in measurement locations (as with Houston).
Finally, remember that some of the hottest and coldest places on earth get very little precipitation. The Sahara and the North and South Poles are all considered deserts based of the amount of precipitation they get.
Net: I find the similarities in the graphs interesting enough to keep digging. As my friend suggested, it would be interesting to find the coefficient of correlation between population growth and temperature change. I won’t leap to any generalizations at this point.
Posted by Bob Rehak on 12/30/2022with thanks to Jeff Lindner, Harris County Meteorologist and Jimmy Fowler of the National Weather Service.
1949 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2022/12/Hobby-Rainfall.png?fit=3144%2C2282&ssl=122823144adminadmin2022-12-30 17:24:042022-12-31 12:50:38Is Precipitation Increasing with Temperature?
Creating a land bank for future flood-mitigation could reduce mitigation costs, speed up projects, and protect the lives and homes of millions.
When we should acquire land for future flood mitigation.When we usually try to acquire it.
Why Flood Mitigation Takes So Long and Costs so Much
Five and a half years after Harvey, officials are still struggling to finance many flood-mitigation projects. Part of the issue has to do with high land-acquisition costs for large, stormwater detention basins and for widening channels.
The San Jacinto River Basin Master Drainage study recommended 16 such projects in the upper basin. The plan includes 10 large regional detention facilities comprising approximately 229,000 ac-ft and six channel projects covering about 38.5 stream miles. Total cost: $2.9 to $3.3 billion (including construction). Land acquisition comprises a large percentage of that total. To put that in perspective, 229,000 acre feet is more than half the capacity of Lake Conroe. And 38.5 miles is exactly the distance from downtown Conroe to downtown Houston. And the cost totals more than Harris County’s 2018 flood bond.
Acquisition costs can vary greatly depending on whether the land is rural or urban; in a flood plain or not; wetlands or not; at a low or high elevation; distance to market; highway access; and other factors.
Ironically, the SJRA studied some of the same recommended detention basins along Spring Creek and its tributaries more than almost 40 years ago. A 1985 study on the Upper River Basin included a chapter on planning. It recommended…
“Right of way and reservoir land acquisition should occur while the land is open and available.”
Had people only listened, taxpayers might have saved a billion dollars or more. Land costs then were a small fraction of today’s. Only 1.8% of the watershed was developed. So why didn’t the interested parties start buying the land back then?
How Benefit/Cost Ratio Can Disincentivize Planning
Even though the costs were far lower, the benefits of buying farm or timber land were even lower still. Developments had to creep much closer before the Benefit/Cost Ratios increased enough to justify the expenditures. But of course, at that point people were already flooding or in danger of flooding. Now, repetitive payouts from the National Flood Insurance Plan help document the “benefits” of buying the land.
So why not create a land bank for future flood mitigation projects?
Buy the land when it’s cheap.
Put it “in the bank.”
Build detention basins on it when needed.
Land-Bank Precedents
There are precedents for this idea.
USDA started its Soil Bank in 1956. Basically, it pays farmers to take land out of production to support crop prices and farm income while preserving soil.
Land banks around the world acquire, hold, manage, and sometimes redevelop property for productive use and to meet community goals, such as increasing affordable housing or stabilizing property values.
Wetlands mitigation banks help preserve valuable wetlands to mitigate damage associated with new developments
HCFCD’s Frontier Program buys up land in rural areas, then develops flood mitigation projects on it. The District sells “detention capacity” to developers to help reduce its costs. This also ensures sufficient capacity for planned developments and optimum efficiency for flood-control projects.
In a similar vein, why not create land banks for flood-mitigation?
Forty years ago, when these projects were first studied, the benefit/cost ratio didn’t justify the purchase. Fast forward.
Benefits of Land Bank
Now, we’re looking at purchasing the same land, but because of inflation and development, the land cost is vastly higher. Had the land been purchased and “banked” way back then, the results would have been:
To be eligible for the proposed flood-mitigation land bank, the land would have to be:
Near a stream or river
Suited for building flood-mitigation projects (i.e., have the right topography)
In or around growing areas, such as Houston, where it would be needed for flood mitigation in a reasonable number of years.
If it contains forests or wetlands, it gets bonus points because its already reducing flooding.
In summary, the idea is to reduce future costs by purchasing land (at market rates) when it’s cheap. It has the added benefits of:
Preserving floodplains, wetlands and forests
Preventing flood damage
Shortening the time needed to develop mitigation projects
How Much Flood Damage Could Have Been Prevented?
The United States needs to re-engineer its flood-mitigation business processes. Flood mitigation takes costs too much and takes too long because we wait too long.
The San Jancinto River Master Drainage Plan released in 2020 points out significant flooding in 1940, 1960, 1973, 1994, 2016, 2017, and 2019 along with numerous other smaller flood events. We’ve been studying the problem for more than 40 years without actually mitigating it. A flood-mitigation land bank could help reduce costs speed up mitigation, and protect people before they flood.
It would be interesting to calculate how much damage could have been prevented in the last four of those floods had all the projects in the 1985 plan been implemented.
Posted by Bob Rehak on 12/28/2022
1947 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2022/12/20220722-RJR_0571.jpg?fit=1200%2C800&ssl=18001200adminadmin2022-12-28 19:56:232022-12-28 20:06:46Create Land Bank for Future Flood-Mitigation Projects
Government Again Moves for Summary Judgment In Addicks-Barker Downstream Cases
On November 21, 2022, the U.S. Government filed a 70-page motion for a summary judgment in the Addicks-Barker Downstream Cases. In 2020, Judge Loren A. Smith dismissed the downstream cases, ruling that the plaintiffs had no right to sue the government for “taking” their property in what he called a 2,000-year storm. However, in June 2022, a federal appeals court reversed Judge Loren’s decision, re-opening the case. The appeals court ruled on a number of procedural issues and remanded the case back to Loren’s court for further consideration.
Both appellants and the government had urged the appeals court to order a summary judgment. But the appeals court declined. It noted that “due to the fact-intensive nature of takings cases, summary judgment should not be granted precipitously.”
Now three years later, the parties are again asking for summary judgement. The government has already filed its motion and the plaintiffs have until January 10, 2023, to respond with their own cross-motion.
Government Claims
In summary, the government contends that the Addicks and Barker dams:
Further, the government contends that plaintiffs’ claims are based on a single, extraordinary, catastrophic event and any action undertaken by the Corps during the event does not constitute a “taking” under the Fifth Amendment.
Dams Modified in Response to Downstream Development
The government brief contains an illuminating historical discussion (starting on Page 23) of how the Army Corps modified the release capacity of the dams over the years in response to downstream development. Both dams release water through concrete box culverts, some of which have been gated to help the Corps reduce discharges.
The original design from the 1930s included a downstream channel with a capacity of approximately 18,000 cubic feet per second (CFS), and 4 ungated and 1 gated outlets on each dam. They permitted a combined, uncontrolled discharge of floodwater into Buffalo Bayou of approximately 15,700 cfs.
In 1948, the Corps constructed gates on two additional conduits on each dam so that three of the five conduits were gated. This design reduced the combined uncontrolled discharge into Buffalo Bayou to approximately 7,900 cfs, which was considered at that time to be the capacity of that channel.
“However, increasing urban development along Buffalo Bayou in the 1940s and 1950s created a potential flood threat from uncontrolled releases at that level,” says the motion.
The Corps then added gates to additional conduits in the early 1960s to provide more protection to developing downstream areas. With all conduits gated, “[t]he total of all releases, plus local runoff downstream of the dams, would start at 4,000 cfs and be gradually increased to 6,000 cfs except under emergency conditions.”
Later, the motion states, “Continued residential development along Buffalo Bayou downstream of the reservoirs resulted in channel encroachment and by late 1970, water flows in excess of 3,000 cfs in the unimproved channel below the dams would begin to threaten the first floor elevations of some residences, and release rates of 2,500 to 2,800 cfs would produce nuisance type flooding of flower beds, trees and lawns in some areas along Buffalo Bayou and its tributaries.”
Causation Argument
Plaintiffs claimed that the opening of the dams’ gates during Harvey caused their flooding. But the government argues that the plaintiffs must demonstrate what would have happened if the government had not acted at all. In other words, the government argues that “causation” must be “based on the entirety of government actions.” See Page 26. That includes construction of the dams! And without them, the government says on Page 42, “properties along Buffalo Bayou would have experienced much greater flooding.”
“Plaintiffs have not alleged—let alone identified any evidence to prove—that their properties experienced more flooding than they would have experienced if the Corps had never constructed the Project, their claims fail,” the government argues.
Doctrine of Relative Benefits
The government also invokes a legal principle called the “relative benefits doctrine.” Under the relative benefits doctrine, “[e]ven if a causal relationship exists between the Government’s action and plaintiff’s damage . . . no liability attaches if the Government’s conduct bestowed more benefit than detriment on plaintiff’s property.”
The motion then alleges that the benefits to downstream properties far outweigh the Harvey-related damages. A 2016 study the government quotes alleges the dams reduced/avoided damages to downstream properties by $16.5 billion. That total is updated annually and based on a with/without the dams comparison.
Comparison of Peak Inflows/Outflows
The government motion cites the following statistics of the two reservoirs during Harvey:
Peak flow rates downstream along Buffalo Bayou ranged from 13,800 cfs to 36,400 cfs. The government alleges that at those levels, plaintiffs properties would flooded regardless of discharge from the dams. The government also alleges that without the dams, flooding in Piney Point would have been 7 to 8 feet higher.
In this section of the motion, government lawyers point out that plaintiffs’ properties would have flooded in previous floods such as Tax Day and Memorial Day had it not been for the dams.
What Constitutes a Taking?
In conclusion, the government argues that the flooding during Harvey did not constitute a “taking” under the Fifth Amendment.
A tort is a failure to take action that results in damage to someone.
To see the exact text of the full 70-page motion, click here.
I will let you know how the plaintiffs’ lawyers respond later this month.
Posted by Bob Rehak on 1/1/2023
1951 Days since Hurricane Harvey
Is Precipitation Increasing with Temperature?
Data provided by the National Weather Service (NWS) shows that precipitation appears to be increasing with temperature in Houston and Harris County. A reader recently asked whether there was a correlation. The hypothesis: in this climate, if temperature increases, then so will evaporation and rainfall. Eighty to 130 years worth of data at different locations show both variables trending up. But most scientists would consider the coefficient of correlation weak to non-existent.
Behind the Theory
The theory is plausible from several perspectives.
But the question concerned correlation, not causation.
Other outside factors could reduce precipitation, such as droughts triggered by changes in Pacific Ocean currents. Those who remember the drought from 2011 to 2014 may also remember how hot it was.
But looking at 80 to 130 years of data highlights long-term climate trends. That “evens out” the influence of individual events.
Qualifiers
NWS plotted all available historical data for precipitation and temperature on line graphs and then superimposed trend lines. The graphs show official data from two sources: Houston-Hobby Airport and the “City of Houston.”
I put City of Houston in quotes because the the official City-of-Houston data is currently collected at Bush Intercontinental Airport. But the location has bounced around. So the “City” isn’t one location, but many:
We have less data for Houston-Hobby because Hobby Airport didn’t exist until 1927. That’s when someone turned a 600-acre pasture into a landing field. The City of Houston purchased the field in 1937 and expanded it.
With those qualifiers, see the charts below. Both temperature and rainfall vary from year to year. But rainfall shows extreme variance. Regardless, in all four graphs the trend lines slowly increase.
Houston-Hobby Airport
City of Houston Data
The City of Houston data covers a wider time period. Within that, the location varied as noted above. The big jump was from downtown to Bush Intercontinental Airport in 1969. Generally speaking, as you go farther north from the coast, precipitation decreases. But the difference is less than an inch. Atlas 14 shows that a 100-year, 24-hour storm is 17.6 inches at Hobby, 17 inches downtown, and 16.9 inches at Intercontinental.
So the change in where the City collects official data actually worked against the hypothesis. And it shows.
Summary of Trend Differences
Summarizing the key differences:
Low Coefficient of Correlation
Jimmy Fowler of the National Weather Service’s Houston/Galveston office calculated the coefficients of correlation between the two series of data at each location.
For those who didn’t study statistics in college, the coefficient of correlation tells you how much one variable changes in response to another.
In both cases, one unit of change in the first variable accounts for an equal unit of change in the second. But most correlations fall between the two extremes with different degrees of strength.
The chart below indicates how scientists would characterize correlation coefficients of .03 and .11. Both are considered “very weak” or having “no association.”
Fit of Trend Lines to Data
So, if the trends are all up, why is the co-efficient of correlation so low? Part of the answer has to do with those R2 (R squared) values you see at the bottom of the charts. They show the data doesn’t conform to the trend lines very well. Temperature fits moderately well. But precipitation shows extreme variance.
A perfect fit (1.0) would show all the data points on the line. As a rule of thumb, 0.8 (80%) or higher is considered a good fit. But the R2 values in these trend lines range from 0.03 to 0.5.
Conclusion
You can read into this data whatever you want depending on your point of view. Climate change advocates might see proof in the consistent slope of the trend lines that warming temperatures and more precipitation are related. A deeper dig into the data reveals the correlation is weak at best and possibly non-existent. Other factors may be at play and influencing the data.
To demonstrate causation, you need to show a directional relationship with no alternative explanations. But with weather, you have a multitude of alternative explanations.
Remember that weather is global and that we looked only at Houston in this instance.
However, a friend who traded weather-related derivatives before retirement tracked hundreds of temperature sites. He found they all trended warmer over time. But he believed the variance resulted primarily from changes in surrounding ground cover, i.e., replacement of natural ground cover with concrete – also known as the urban heat island effect.
He also tracked variance to changes in measurement locations (as with Houston).
Finally, remember that some of the hottest and coldest places on earth get very little precipitation. The Sahara and the North and South Poles are all considered deserts based of the amount of precipitation they get.
Net: I find the similarities in the graphs interesting enough to keep digging. As my friend suggested, it would be interesting to find the coefficient of correlation between population growth and temperature change. I won’t leap to any generalizations at this point.
Posted by Bob Rehak on 12/30/2022 with thanks to Jeff Lindner, Harris County Meteorologist and Jimmy Fowler of the National Weather Service.
1949 Days since Hurricane Harvey
Create Land Bank for Future Flood-Mitigation Projects
Creating a land bank for future flood-mitigation could reduce mitigation costs, speed up projects, and protect the lives and homes of millions.
Why Flood Mitigation Takes So Long and Costs so Much
Five and a half years after Harvey, officials are still struggling to finance many flood-mitigation projects. Part of the issue has to do with high land-acquisition costs for large, stormwater detention basins and for widening channels.
The San Jacinto River Basin Master Drainage study recommended 16 such projects in the upper basin. The plan includes 10 large regional detention facilities comprising approximately 229,000 ac-ft and six channel projects covering about 38.5 stream miles. Total cost: $2.9 to $3.3 billion (including construction). Land acquisition comprises a large percentage of that total. To put that in perspective, 229,000 acre feet is more than half the capacity of Lake Conroe. And 38.5 miles is exactly the distance from downtown Conroe to downtown Houston. And the cost totals more than Harris County’s 2018 flood bond.
Acquisition costs can vary greatly depending on whether the land is rural or urban; in a flood plain or not; wetlands or not; at a low or high elevation; distance to market; highway access; and other factors.
Ironically, the SJRA studied some of the same recommended detention basins along Spring Creek and its tributaries more than almost 40 years ago. A 1985 study on the Upper River Basin included a chapter on planning. It recommended…
Had people only listened, taxpayers might have saved a billion dollars or more. Land costs then were a small fraction of today’s. Only 1.8% of the watershed was developed. So why didn’t the interested parties start buying the land back then?
How Benefit/Cost Ratio Can Disincentivize Planning
Even though the costs were far lower, the benefits of buying farm or timber land were even lower still. Developments had to creep much closer before the Benefit/Cost Ratios increased enough to justify the expenditures. But of course, at that point people were already flooding or in danger of flooding. Now, repetitive payouts from the National Flood Insurance Plan help document the “benefits” of buying the land.
So why not create a land bank for future flood mitigation projects?
Land-Bank Precedents
There are precedents for this idea.
In a similar vein, why not create land banks for flood-mitigation?
The genesis of the idea came from an observation about the two areas under consideration now for two floodwater detention basins on Spring Creek.
Forty years ago, when these projects were first studied, the benefit/cost ratio didn’t justify the purchase. Fast forward.
Benefits of Land Bank
Now, we’re looking at purchasing the same land, but because of inflation and development, the land cost is vastly higher. Had the land been purchased and “banked” way back then, the results would have been:
By waiting until land is developed and people flood, we get to pay twice – for their land and for their damages through the NFIP. And project length can drag out for decades.
To be eligible for the proposed flood-mitigation land bank, the land would have to be:
If it contains forests or wetlands, it gets bonus points because its already reducing flooding.
In summary, the idea is to reduce future costs by purchasing land (at market rates) when it’s cheap. It has the added benefits of:
How Much Flood Damage Could Have Been Prevented?
The United States needs to re-engineer its flood-mitigation business processes. Flood mitigation takes costs too much and takes too long because we wait too long.
The San Jancinto River Master Drainage Plan released in 2020 points out significant flooding in 1940, 1960, 1973, 1994, 2016, 2017, and 2019 along with numerous other smaller flood events. We’ve been studying the problem for more than 40 years without actually mitigating it. A flood-mitigation land bank could help reduce costs speed up mitigation, and protect people before they flood.
It would be interesting to calculate how much damage could have been prevented in the last four of those floods had all the projects in the 1985 plan been implemented.
Posted by Bob Rehak on 12/28/2022
1947 Days since Hurricane Harvey