Did you know that one-third of the area in Harris County now has impervious cover? That Montgomery County had a 57.12% net increase of impervious surface area between 2001 and 2019? Or that 10% of land cover in the Lower 48 states changed during that same period? I discovered these and a multitude of other fascinating facts in a recently updated United States Geological Survey (USGS) website dedicated to monitoring changes in land cover, for example, from forested to developed.
When you live in an area for a long time, it’s easy to forget what happened two decades ago. And when you move to a new area, you just accept what is and don’t worry about what was.
But USGS gives you a quick and easy way to see and quantify changes in land use down to the county level. It’s useful in telling you where flood threats could develop over time and how fast they are developing.
About the USGS National Land Cover Database
USGS recently released updated land cover maps for the lower 48 United States. They show how the country’s landscapes have changed over an 18 year period in two- to three-year increments. It’s called the United States National Land Cover Database (NLCD). And it’s the fastest way to see how your county is changing.
Updates include 2001, 2004, 2006, 2008, 2011, 2013, 2016, and 2019.
Developed using Landsat imagery, NLCD classifies land cover into 16 groups with 30-meter resolution. The data includes both land-cover and urban imperviousness changes.
USGS claims 91 percent accuracy for the NLCD data. For more detail about how NLCD was developed see: Changes to the National Land Cover Database. More than nine billion pixels make up the land-cover dataset.
The USGS National Land Cover Database’s suite of GIS mapping products even includes a layer that defines the intensity of impervious surfaces across the United States. This information is used in runoff modeling, urban heat estimation, and a variety of other applications.
Mapping Land Cover Change in U.S. Over Time
Users can visualize land cover changes in the United States by accessing the the Enhanced Visualization and Analysis (EVA) tool. The online mapping tool was developed by USGS in partnership with the National Oceanic and Atmospheric Administration.
The tool allows users to select any county in the Lower-48 United States and generate a custom report on land cover change, developed areas, cropland change, and other factors.
Only one caution: the USGS site does not work with Apple’s Safari Browser. Mac users can use Firefox without problems, however. I have not tested other Mac browsers.
Almost one fifth of the land cover changed type (18.23%).
Developed portions of the county increased from 54.42% to 65.85% of the total acreage, a 20.99% percent net increase of developed area.
Forested parts of the county went from 10.64% to 6.29%, a percent net decrease of 40.92%.
The percent covered in wetlands went down from 8.28% to 7.02%, another percent net decrease of 15.24%.
The percentage of impervious surface increased from about a quarter to a third (26.28% to 33.39%), a percent net increase of 27.05%.
Screen showing development changes in Harris County with corresponding percentages of impervious cover. Green dots represent changes in land use.Clicking on icons in left column brings up different types of information.
MoCo Changes at a Glance
During the same period, in Montgomery County:
Even more land cover changed type (18.99%).
Developed portions of the county increased from 21.1% of the land area to 28.27%, a 33.97% net increase.
Impervious cover increased from 5.78% off the land area to 9.08%, a 57.12% increase.
Forested land decreased from 42.98% of the county to 38.96%, a 9.16% net decrease.
Wetlands decreased from 12.17% of the county to 11.35%, a 6.74% net decrease.
Agricultural land decreased from 12.28% to 10.31% of the county, a 16.04% net decrease.
Red areas represent areas in Montgomery County that changed land-cover type between 2001 and 2019.
Another screen showing areas in Montgomery County developed between 2001 and 2019.
Key Lesson
This database and GIS mapping system dramatize how quickly the region is growing and land use is changing.
Flood mitigation is or should be a two-pronged effort. We must fix problems that already exist downstream while hopefully preventing future problems from developing upstream. It’s not a just question of one county spending money to help prevent problems in another. It’s about surrounding counties protecting themselves. The outward expansion is relentless. People at the edge today will be downstream from someone else tomorrow.
There’s little anyone can do to change the FACT of development. But we can change the NATURE of development. If all new developments retained their own rain, no one would ever be doomed to the flood-mitigation treadmill of keeping up with ever-increasing amounts of upstream runoff.
Montgomery County already has a serious flooding problem of its own. Thousands of people flooded there during Harvey and Imelda.
Posted by Bob Rehak on 8/5/2021based on USGS information
1437 Days since Hurricane Harvey
The thoughts expressed in this post represent opinions on matters of public concern and safety. They are protected by the First Amendment of the US Constitution and the Anti-SLAPP Statute of the Great State of Texas.
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2021/08/Harris-Developed.jpg?fit=1200%2C582&ssl=15821200adminadmin2021-08-05 17:34:302021-08-06 11:42:27USGS Says One Third of Harris County Now Impervious Cover
On June 29, 2021, Harris County Commissioners approved two contracts for preliminary engineering on the Kingwood Diversion Ditch and Taylor Gully Projects. This week, I’ve been getting reports of boots on the ground. So I grabbed my camera and went looking for activity this morning. I found a soil survey truck at Kingwood Drive next to the Diversion Ditch. I also found regular surveyors on Taylor Gully about a block south of Woodridge Village.
Both activities are among the first steps in preliminary engineering. And both are among the first steps in finding flood-mitigation solutions for a huge percentage of Kingwood’s population.
This drone shot shows the surveying crew a little more than one block south of Woodridge Village on Taylor Gully.
Looking downstream in opposite direction toward Rustic Elm Bridge out of sight around bend.
The surveyors were capturing elevations of the banks, slopes, ditch bottom, and backslope swalesof Taylor Gully.
Taylor Gully Objectives and Scope
HCFCD has asked Idcus, Inc. to develop up to five conceptual alternative scenarios for modifying Taylor Gully. Alternative scenarios may include:
Expanding Detention On Woodridge Village Site so that no channel improvements are necessary.
Determining amount of detention and channel improvements necessary to ensure no adverse impact all the way to Lake Houston.
Finding the optimum balance between maximum flood protection and minimum construction costs.
Deliverables include:
Channel and basin layouts
Estimates of benefits for various levels of storms (100-year, etc.)
Right-of-way requirements
Cost estimates for right-of-way acquisition, engineering and construction management.
Performance metrics, i.e., estimated acreage of land inundation, number of structures in floodplain, number of structures flooded and miles of inundated roadway.
A scoring matrix to rank alternatives.
Scope of Taylor Gully Project includes the two halves of Woodridge Village outlined in gold above the ditch.
Kingwood Diversion Ditch Objectives and Scope
HCFCD hired Neel-Schaffer, Inc. for preliminary Kingwood Diversion Ditch engineering. They must:
Evaluate existing site conditions, previous studies, other projects that could affect this one, topography, rights-of-way, utilities, and soil surveys.
Evaluate existing bridges
Conduct and H&H analysis to assess existing and proposed conditions (from 2-year to 500-year storms).
Analyze Channel Improvements including the:
Impact of TIRZ #10’s latest design to replace the Northpark Bridge
Diversion structure at the confluence of Bens Branch and the Diversion Channel
Drop structures in lieu of a concrete lined channel to minimize high velocities due to the steep grade between Walnut Lane and Deer Ridge Estates Blvd.
Develop phased construction plans based on available funding, potential impacts and benefits.
Conduct two public engagement meetings and coordinate with community groups.
Deliverables include:
Surveys
Geotechnical investigations, i.e., bridge borings
Environmental assessment
“Jurisdictional” determination. Does this channel fall under the jurisdiction of the Army Corps as it nears the West Fork? If so, channel design may need to be altered.
Determination of detention pond requirements
Exploration for subsurface utilities
Obtaining permits from the Corps
Landscape architect services
Scope of Diversion Ditch Project runs from St. Martha Catholic Church in Montgomery County to the San Jacinto West Fork at River Grove Park. This is the ditch that runs past the fire station on Kingwood Drive.
Why These Two Projects First?
Both of these projects evolved from the Kingwood Drainage Analysis finalized late last year. That study identified nine channels that needed improvement. These two were recommended for immediate help because:
They help the largest number of people.
HCFCD already owns land to expand and deepen the Diversion Ditch.
Diversion Ditch enhancement will immediately take pressure off Ben’s Branch, and help flooding there.
Note that Ben’s Branch has already gone through a four-phase major maintenance project designed to restore its original conveyance.
Here is Harris County Flood Control District’s Summary of Results from the 600-page Kingwood Area Drainage Analysis.
A Good Sign
Both of these projects go far beyond maintenance, which portions of both of these ditches have already received. While we’re still far from construction, the work that kicked off this week will improve flood safety for a large part of Kingwood.
Posted by Bob Rehak on 8/4/2021
1436 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2021/08/20210804-RJR_8789.jpg?fit=1200%2C800&ssl=18001200adminadmin2021-08-04 14:00:282021-08-04 14:27:38Kingwood Diversion Ditch and Taylor Gully Preliminary Engineering Projects Begin
Want to learn how to create healthy, resilient, natural spaces in your community that can mitigate the effects of flooding? Harris County Precinct 4 will sponsor a free event this weekend at Jesse Jones Park called “Floods and Phytoremediation.”
The event will be held indoors in the park’s Nature Center. People can also participate virtually via Zoom. To register for the virtual alternative, click here. Drop-ins are welcome for the in-person option; no registration is necessary.
What is Phytoremediation?
This event definitely takes the prize for Best Title in the Curiosity Category. I didn’t even know what phytoremediation was. But once I looked it up, I got very interested.
Phytoremediation uses living plants to clean up soil, air, and water contaminated with certain types of hazardous contaminants. The term is a marriage of the Greek phyto (plant) and Latin remedium (restoring balance). It takes advantage of plants’ abilities to concentrate elements and compounds from the environment and to detoxify various organic compounds.
Goal of Program
Organizers of the program hope to make the community more resilient to extreme precipitation events by making people more knowledgeable about the possibilities and getting them more involved.
Staff and volunteers at Jesse Jones Park hope to plant thousands of trees and other vegetation along the creek this fall and winter to:
Help slow and absorb flood waters
Phytoremediate toxins
Prevent erosion
Beautify the area.
“Once established, these areas could be utilized in the research about phytoremediation,” said Jason Naivar, the Superintendent of Jesse Jones Park.
Grants from NOAA and the Boston Museum of Science helped make the program possible.
Learn More about Health Hazards of Extreme Flooding and How Plants Can Reduce Toxicity
Jesse Jones Park and Lonestar College-Kingwood have partnered to bring together experts to speak about the health hazards of extreme flooding. They will also focus on how native plants can help reduce the toxicity of these events.
Speakers include:
Jason Naivar-Superintendent of Jesse Jones Park introduce the program and explain the history of flooding in Jones Park.
Theresa Harris of American Association for the Advancement of Science will speak on initiating public engagement projects.
Dr. Kristy Daniel of Texas State University will speak on volunteer training in science.
Dr. Brian Shmaefsky from Lone Star College Kingwood will discuss general aspects of phytoremediation.
Professor Xingmao (Sam) Ma of Texas A&M University will focus on phytotechnology related to civil engineering practices.
All Jones Park events allow for proper social distancing. Bring your own water bottle, however. Due to Covid concerns, the park’s water coolers are still shut down.
Posted by Bob Rehak on 8/3/2021
1435 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2021/08/20210803-Screen-Shot-2021-08-03-at-3.23.39-PM-copy.jpg?fit=924%2C1200&ssl=11200924adminadmin2021-08-03 15:40:092021-08-03 15:42:15Don’t Miss “Floods and Phytoremediation” This Saturday At Jesse Jones Park
USGS Says One Third of Harris County Now Impervious Cover
Did you know that one-third of the area in Harris County now has impervious cover? That Montgomery County had a 57.12% net increase of impervious surface area between 2001 and 2019? Or that 10% of land cover in the Lower 48 states changed during that same period? I discovered these and a multitude of other fascinating facts in a recently updated United States Geological Survey (USGS) website dedicated to monitoring changes in land cover, for example, from forested to developed.
When you live in an area for a long time, it’s easy to forget what happened two decades ago. And when you move to a new area, you just accept what is and don’t worry about what was.
But USGS gives you a quick and easy way to see and quantify changes in land use down to the county level. It’s useful in telling you where flood threats could develop over time and how fast they are developing.
About the USGS National Land Cover Database
USGS recently released updated land cover maps for the lower 48 United States. They show how the country’s landscapes have changed over an 18 year period in two- to three-year increments. It’s called the United States National Land Cover Database (NLCD). And it’s the fastest way to see how your county is changing.
Updates include 2001, 2004, 2006, 2008, 2011, 2013, 2016, and 2019.
Developed using Landsat imagery, NLCD classifies land cover into 16 groups with 30-meter resolution. The data includes both land-cover and urban imperviousness changes.
USGS claims 91 percent accuracy for the NLCD data. For more detail about how NLCD was developed see: Changes to the National Land Cover Database. More than nine billion pixels make up the land-cover dataset.
The USGS National Land Cover Database’s suite of GIS mapping products even includes a layer that defines the intensity of impervious surfaces across the United States. This information is used in runoff modeling, urban heat estimation, and a variety of other applications.
Mapping Land Cover Change in U.S. Over Time
Users can visualize land cover changes in the United States by accessing the the Enhanced Visualization and Analysis (EVA) tool. The online mapping tool was developed by USGS in partnership with the National Oceanic and Atmospheric Administration.
The tool allows users to select any county in the Lower-48 United States and generate a custom report on land cover change, developed areas, cropland change, and other factors.
Only one caution: the USGS site does not work with Apple’s Safari Browser. Mac users can use Firefox without problems, however. I have not tested other Mac browsers.
I ran two quick searches on Harris and Montgomery Counties by going to the EVA tool mentioned above. The findings astonished me.
Harris County Changes At a Glance
Between 2001 and 2019, in Harris County:
MoCo Changes at a Glance
During the same period, in Montgomery County:
Key Lesson
This database and GIS mapping system dramatize how quickly the region is growing and land use is changing.
Flood mitigation is or should be a two-pronged effort. We must fix problems that already exist downstream while hopefully preventing future problems from developing upstream. It’s not a just question of one county spending money to help prevent problems in another. It’s about surrounding counties protecting themselves. The outward expansion is relentless. People at the edge today will be downstream from someone else tomorrow.
There’s little anyone can do to change the FACT of development. But we can change the NATURE of development. If all new developments retained their own rain, no one would ever be doomed to the flood-mitigation treadmill of keeping up with ever-increasing amounts of upstream runoff.
Montgomery County already has a serious flooding problem of its own. Thousands of people flooded there during Harvey and Imelda.
Posted by Bob Rehak on 8/5/2021 based on USGS information
1437 Days since Hurricane Harvey
The thoughts expressed in this post represent opinions on matters of public concern and safety. They are protected by the First Amendment of the US Constitution and the Anti-SLAPP Statute of the Great State of Texas.
Kingwood Diversion Ditch and Taylor Gully Preliminary Engineering Projects Begin
On June 29, 2021, Harris County Commissioners approved two contracts for preliminary engineering on the Kingwood Diversion Ditch and Taylor Gully Projects. This week, I’ve been getting reports of boots on the ground. So I grabbed my camera and went looking for activity this morning. I found a soil survey truck at Kingwood Drive next to the Diversion Ditch. I also found regular surveyors on Taylor Gully about a block south of Woodridge Village.
Both activities are among the first steps in preliminary engineering. And both are among the first steps in finding flood-mitigation solutions for a huge percentage of Kingwood’s population.
Taylor Gully Objectives and Scope
HCFCD has asked Idcus, Inc. to develop up to five conceptual alternative scenarios for modifying Taylor Gully. Alternative scenarios may include:
Deliverables include:
Kingwood Diversion Ditch Objectives and Scope
HCFCD hired Neel-Schaffer, Inc. for preliminary Kingwood Diversion Ditch engineering. They must:
Walnut Lane and Deer Ridge Estates Blvd.
Deliverables include:
Why These Two Projects First?
Both of these projects evolved from the Kingwood Drainage Analysis finalized late last year. That study identified nine channels that needed improvement. These two were recommended for immediate help because:
Note that Ben’s Branch has already gone through a four-phase major maintenance project designed to restore its original conveyance.
Here is Harris County Flood Control District’s Summary of Results from the 600-page Kingwood Area Drainage Analysis.
A Good Sign
Both of these projects go far beyond maintenance, which portions of both of these ditches have already received. While we’re still far from construction, the work that kicked off this week will improve flood safety for a large part of Kingwood.
Posted by Bob Rehak on 8/4/2021
1436 Days since Hurricane Harvey
Don’t Miss “Floods and Phytoremediation” This Saturday At Jesse Jones Park
Want to learn how to create healthy, resilient, natural spaces in your community that can mitigate the effects of flooding? Harris County Precinct 4 will sponsor a free event this weekend at Jesse Jones Park called “Floods and Phytoremediation.”
It starts at 1PM, 20634 Kenswick Drive, Humble, TX 77338 near Spring Creek. For directions, click here.
The event will be held indoors in the park’s Nature Center. People can also participate virtually via Zoom. To register for the virtual alternative, click here. Drop-ins are welcome for the in-person option; no registration is necessary.
What is Phytoremediation?
This event definitely takes the prize for Best Title in the Curiosity Category. I didn’t even know what phytoremediation was. But once I looked it up, I got very interested.
Phytoremediation uses living plants to clean up soil, air, and water contaminated with certain types of hazardous contaminants. The term is a marriage of the Greek phyto (plant) and Latin remedium (restoring balance). It takes advantage of plants’ abilities to concentrate elements and compounds from the environment and to detoxify various organic compounds.
Goal of Program
Organizers of the program hope to make the community more resilient to extreme precipitation events by making people more knowledgeable about the possibilities and getting them more involved.
Staff and volunteers at Jesse Jones Park hope to plant thousands of trees and other vegetation along the creek this fall and winter to:
“Once established, these areas could be utilized in the research about phytoremediation,” said Jason Naivar, the Superintendent of Jesse Jones Park.
Grants from NOAA and the Boston Museum of Science helped make the program possible.
Learn More about Health Hazards of Extreme Flooding and How Plants Can Reduce Toxicity
Jesse Jones Park and Lonestar College-Kingwood have partnered to bring together experts to speak about the health hazards of extreme flooding. They will also focus on how native plants can help reduce the toxicity of these events.
Speakers include:
All Jones Park events allow for proper social distancing. Bring your own water bottle, however. Due to Covid concerns, the park’s water coolers are still shut down.
Posted by Bob Rehak on 8/3/2021
1435 Days since Hurricane Harvey