I took this picture on May 26, 2021. It shows TxDOT construction of the new State Highway 99 (Grand Parkway) next to FM1485 in New Caney. The picture looks northeast toward Colony Ridge in Liberty County. The East Fork of the San Jacinto River flows under both bridges toward Lake Houston on the right.
Looking east toward Colony Ridge across FM1485 and the East Fork. Water flows left to right.
Note the huge backup of water trying to get under the FM1485 bridge. Also note how much taller and wider the new bridge is compared to the old one.
How Much Rainfall Caused This?
Here is rainfall for the month of May as measured by the Harris County Flood Control District Gage at this location.
The Harris County Flood Warning System shows that the largest rainfall for the month was 2.28 inches TWO days before the photo. But the ground was clearly saturated from steady, moderate rains the week before.
The gage upstream at FM2090 shows slightly more rain. It reported 14 inches for the month instead of 11, but it received exactly 2.28 inches on the same day this gage did. While 2+ inches in a day is substantial, few in this part of the world would consider it excessive – especially since it was spread out over 5 hours.
Likewise, according to Atlas-14 standards, the rain that fell in the week before would qualify as a 1- to 2-year rain – notable, but not historic.
Note the 7-day rainfall totals in columns 1 and 2.
Submerged 41 Times in 32 years
And after consulting Harris County Flood Control District records, I learned that FM1485 has gone under water 41 times since 1990 – an average of 1.32 times per year.
The East Fork came out of its banks and flooded this area twice in the week before the picture was taken.
Rainfall data, road flooding frequency and the photo all suggest that a 1- to 2-year rain is enough to flood FM1485.
What Should a Roadway over a Major River Withstand?
Obviously TxDOT built a much higher road and a much wider, taller bridge for its new highway. The new one is approximately five times wider than the old one. Construction standards for major highways could account for that. But so could TxDOT’s experience with FM1485.
So What’s Going on Here?
Why did TxDOT make the new bridge so much wider and taller?
Did TxDOT just get the engineering wrong on the old bridge?
Did bridge standards change over time?
Do state highways have higher standards than farm-to-market roads?
Jeff Lindner, Harris County’s meteorologist, cautions that, “Water surface elevations depend on many variables…rainfall patterns, intensity, soil conditions, water level in the river when the rain started, ect. It is usually difficult to compare events as no two are exactly alike. You really need a hydrological analysis of the location to determine the amount of run-off from that site into the river per an amount of rainfall.”
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/2021/07/20210526-RJR_8369.jpg?fit=1200%2C800&ssl=18001200adminadmin2021-07-14 21:15:042021-07-15 11:54:40FM1485: What’s Wrong With This Picture?
Harris County Flood Control District’s (HCFCD) Frontier Program is an effort to avoid the problems of past development in newly developing areas. In the past, making developers solely responsible for flood mitigation on the land they owned likely resulted in small, expensive and suboptimal projects. Often, by the time shortcomings of their efforts became apparent, it was too late to do anything. Sometimes, to make room for effective flood-mitigation projects, whole subdivisions had to be bought out – after years of repetitive flooding. See two images below.
Halls Bayou next to the Fiesta on US59 north in 2002. Note the subdivisions on either side of the freeway and compare this shot to the one below.To create the detention ponds on either side of the freeway, HCFCD had to buy out entire subdivisions, an effort that took more than a decade.The buyouts took 4-5 times longer than construction of the ponds.
Frontier Program Offers a Different Paradigm
The Frontier Program is an organized effort to plan for regional drainage infrastructure in advance of future land development.
Program managers work with developers and landowners to identify large-scale, mutually beneficial projects for drainage that cost-effectively maximize stormwater mitigation and water quality. Plans also include opportunities for public recreation and open space.
Basically, instead of forcing all the responsibility for floodwater detention onto developers, the developers buy detention capacity from HCFCD. But the detention capacity is in larger, more efficient ponds in optimal locations – large enough to accommodate future growth.
Currently HCFCD district has frontier programs operating in two watersheds: Little Cypress Creek and Langham Creek, both in northwest Harris County.
Little Cypress Creek Frontier Program
Little Cypress Creek’s watershed is 52-square-miles, but it has fewer than 30,000 residents. However, Little Cypress Creek is experiencing rapid development with construction of the Grand Parkway and lacks sufficient natural drainage to accommodate expected growth.
The 2018 flood-bond funded the watershed’s Master Drainage Plan, as well as stormwater conveyance improvements on Little Cypress Creek from Cypress Rosehill to the confluence with Cypress Creek.
This innovative approach is in contrast to typical efforts in which individual land owners and developers install drainage infrastructure that serves their sites alone, resulting in smaller, isolated stormwater detention basins and minimum-width channels for stormwater management. By taking a regional approach, the Frontier Program protects existing developments and provides proper drainage for newly developing properties.
Developers participate in the Frontier Program by paying a $4,000-per-acre fee to develop in the watershed service area. Developers also participate by excavating a portion of regional drainage facilities and by dedicating property for right-of-way. The Little Cypress Creek Frontier Program will use impact fees primarily to acquire additional right-of-way along the channel and for stormwater detention basins.
Bottom line: the program calls for stricter stormwater detention requirements to mitigate runoff from new developments.
Upper Langham Creek Frontier Program
HCFCD operates another Frontier Program on Upper Langham Creek in its 16 square-mile watershed.
Major elements include, but are not limited to:
The 190-acre Greenhouse Stormwater Detention Basin in Harris County Precinct 3. The basin ultimately will provide approximately 860 acre-feet of detention storage.
Another 865-acre basin site at Precinct 3’s John Paul’s Landing Park. It will provide 2,360 acre-feet of detention storage.
A six-mile, 700-foot-wide, 14-foot-deep floodplain and stream corridor encompassing Langham Creek between the two basins. The variable-width, undulating corridor design features wide flood terraces (or benches), gentle side slopes and in-line detention storage volume for the mitigation of stormwater flows. Within the corridor, Langham Creek will be redesigned as a natural stable stream, with adjacent forested borders, native grasses, and stormwater quality mitigation features.
Here, developers pay a per-acre impact fee of $3,100.
Pay Now or Pay Later
Some residents have complained about spending HCFCD funds in areas where people do not yet live when they flood now.
But this is truly a case of “You can pay me now or pay me later.” And if you pay later, the cost is almost certain to be exponentially higher and take much longer…after a lot of heartbreak, misery and human suffering.
Analogy: think about a doctor who’s so busy dealing with critical care, she has no time to deal with preventive care.
Posted by Bob Rehak on 7/13/2021
1414 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2021/07/20210713-Screen-Shot-2021-07-13-at-6.04.17-PM.jpg?fit=1200%2C622&ssl=16221200adminadmin2021-07-13 18:17:032021-07-13 18:47:51HCFCD’s “Frontier Program”: A Collaborative Model for Future Flood Mitigation
Between US59 and Sorters-McClellan Road, a few blocks south of Kingwood Drive, New Caney ISD High School #3 is finally taking shape. And it now has an official name: West Fork High High School.
On January 1, 2021, contractors were just starting to pour concrete for the foundations and parking lots. According to the New Caney ISD’s June update:
Site work storm drainage is 95 percent complete
Sanitary sewer system – 85 percent.
Electrical system – 98 percent.
Water system – 90 percent.
Building concrete slab – 90 percent.
Form and pour tilt-up panels – 99 percent.
Erect panels – 95 percent.
Structural steel – 55 percent.
Metal decking – 20 percent.
Concrete masonry unit (cinder block) masonry – 10 percent.
Aerial Photos Taken 7.12.21
Here’s how all that looked on the afternoon of July 12, 2021.
Looking NE from over Sorters-McClellan Road toward Kingwood Medical Center and Insperity (top center).Looking east toward Field House and where playing fields will go just beyond it. US59 and Lowe’s in background.Looking south at entire site. Sorters-McClellan Road on right. US59 on left and top.A peak into New Caney ISD’s West Fork High School three-story structuresLooking north at entire site. Huge detention pond in foreground. Looking North. Corrugated metal installed as base for roofing on four buildings.
Site Plan, Architectural Renderings for New Caney ISD West Fork High School
Here’s how it should all look when finished.
Architectural Rendering courtesy of New Caney ISD.
Architectural Rendering courtesy of New Caney ISD.
Architectural Rendering courtesy of New Caney ISD.
General plan for New Caney High School #3
New Caney ISD expects to finish construction on the 60-acre site in the summer of 2022. The site is in Montgomery County, but also the City of Houston’s Extra-Territorial Jurisdiction.
Detention Pond Requirements
The dry-bottom detention pond takes up approximately 5 of the 60 acres – or one twelfth of the site. Assuming it’s 12 feet deep, it would hold a foot of rain falling on the entire site. The new minimum recommendation for a site this size in Harris County and the City is .65 acre feet of detention per acre. That would be about 40 acre-feet of detention, which a pond 8 feet deep would hold.
Because the construction site is closed, and the plans I have don’t specify depth, it’s hard to say exactly how much capacity the detention pond has. But I’m guessing it’s deep enough to meet the new minimum requirements under Atlas 14. I say that judging by the height of the pond walls compared to the pipes leading into it.
I would expect no less from a public school system.
Posted by Bob Rehak on 7/12/2021
1413 Days after Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2021/07/20210712-DJI_0066.jpg?fit=1200%2C799&ssl=17991200adminadmin2021-07-12 17:54:312021-07-12 17:55:11New Caney ISD’s New West Fork High School Taking Shape
FM1485: What’s Wrong With This Picture?
I took this picture on May 26, 2021. It shows TxDOT construction of the new State Highway 99 (Grand Parkway) next to FM1485 in New Caney. The picture looks northeast toward Colony Ridge in Liberty County. The East Fork of the San Jacinto River flows under both bridges toward Lake Houston on the right.
How Much Rainfall Caused This?
Here is rainfall for the month of May as measured by the Harris County Flood Control District Gage at this location.
The gage upstream at FM2090 shows slightly more rain. It reported 14 inches for the month instead of 11, but it received exactly 2.28 inches on the same day this gage did. While 2+ inches in a day is substantial, few in this part of the world would consider it excessive – especially since it was spread out over 5 hours.
Likewise, according to Atlas-14 standards, the rain that fell in the week before would qualify as a 1- to 2-year rain – notable, but not historic.
Submerged 41 Times in 32 years
And after consulting Harris County Flood Control District records, I learned that FM1485 has gone under water 41 times since 1990 – an average of 1.32 times per year.
Rainfall data, road flooding frequency and the photo all suggest that a 1- to 2-year rain is enough to flood FM1485.
What Should a Roadway over a Major River Withstand?
Yet the TxDOT standard suggests that such minor arterials and bridges over a major river crossing be built to withstand 25- to 50-year floods. Oops!
Obviously TxDOT built a much higher road and a much wider, taller bridge for its new highway. The new one is approximately five times wider than the old one. Construction standards for major highways could account for that. But so could TxDOT’s experience with FM1485.
So What’s Going on Here?
Why did TxDOT make the new bridge so much wider and taller?
Jeff Lindner, Harris County’s meteorologist, cautions that, “Water surface elevations depend on many variables…rainfall patterns, intensity, soil conditions, water level in the river when the rain started, ect. It is usually difficult to compare events as no two are exactly alike. You really need a hydrological analysis of the location to determine the amount of run-off from that site into the river per an amount of rainfall.”
Good luck with that! More than six months after the Liberty County Attorney launched an investigation into Colony Ridge drainage reports, we still are waiting for answers.
Posted by Bob Rehak on 7/15/2021
1415 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.
HCFCD’s “Frontier Program”: A Collaborative Model for Future Flood Mitigation
Harris County Flood Control District’s (HCFCD) Frontier Program is an effort to avoid the problems of past development in newly developing areas. In the past, making developers solely responsible for flood mitigation on the land they owned likely resulted in small, expensive and suboptimal projects. Often, by the time shortcomings of their efforts became apparent, it was too late to do anything. Sometimes, to make room for effective flood-mitigation projects, whole subdivisions had to be bought out – after years of repetitive flooding. See two images below.
Frontier Program Offers a Different Paradigm
The Frontier Program is an organized effort to plan for regional drainage infrastructure in advance of future land development.
Program managers work with developers and landowners to identify large-scale, mutually beneficial projects for drainage that cost-effectively maximize stormwater mitigation and water quality. Plans also include opportunities for public recreation and open space.
Basically, instead of forcing all the responsibility for floodwater detention onto developers, the developers buy detention capacity from HCFCD. But the detention capacity is in larger, more efficient ponds in optimal locations – large enough to accommodate future growth.
Currently HCFCD district has frontier programs operating in two watersheds: Little Cypress Creek and Langham Creek, both in northwest Harris County.
Little Cypress Creek Frontier Program
Little Cypress Creek’s watershed is 52-square-miles, but it has fewer than 30,000 residents. However, Little Cypress Creek is experiencing rapid development with construction of the Grand Parkway and lacks sufficient natural drainage to accommodate expected growth.
The Little Cypress Creek Frontier Program includes nine stormwater detention basins and stormwater conveyance improvements along the creek and its tributaries. The detention basins will hold more than 20,000 acre feet of stormwater. Together with conveyance improvements, flooding should be reduced 5-7 feet. This video, featuring Alan Black, HCFCD’s new acting director who lives in the area, explains how the collaborative effort with developers works.
The 2018 flood-bond funded the watershed’s Master Drainage Plan, as well as stormwater conveyance improvements on Little Cypress Creek from Cypress Rosehill to the confluence with Cypress Creek.
This innovative approach is in contrast to typical efforts in which individual land owners and developers install drainage infrastructure that serves their sites alone, resulting in smaller, isolated stormwater detention basins and minimum-width channels for stormwater management. By taking a regional approach, the Frontier Program protects existing developments and provides proper drainage for newly developing properties.
Developers participate in the Frontier Program by paying a $4,000-per-acre fee to develop in the watershed service area. Developers also participate by excavating a portion of regional drainage facilities and by dedicating property for right-of-way. The Little Cypress Creek Frontier Program will use impact fees primarily to acquire additional right-of-way along the channel and for stormwater detention basins.
Upper Langham Creek Frontier Program
HCFCD operates another Frontier Program on Upper Langham Creek in its 16 square-mile watershed.
Major elements include, but are not limited to:
Pay Now or Pay Later
Some residents have complained about spending HCFCD funds in areas where people do not yet live when they flood now.
But this is truly a case of “You can pay me now or pay me later.” And if you pay later, the cost is almost certain to be exponentially higher and take much longer…after a lot of heartbreak, misery and human suffering.
Analogy: think about a doctor who’s so busy dealing with critical care, she has no time to deal with preventive care.
Posted by Bob Rehak on 7/13/2021
1414 Days since Hurricane Harvey
New Caney ISD’s New West Fork High School Taking Shape
Between US59 and Sorters-McClellan Road, a few blocks south of Kingwood Drive, New Caney ISD High School #3 is finally taking shape. And it now has an official name: West Fork High High School.
On January 1, 2021, contractors were just starting to pour concrete for the foundations and parking lots. According to the New Caney ISD’s June update:
Aerial Photos Taken 7.12.21
Here’s how all that looked on the afternoon of July 12, 2021.
Site Plan, Architectural Renderings for New Caney ISD West Fork High School
Here’s how it should all look when finished.
New Caney ISD expects to finish construction on the 60-acre site in the summer of 2022. The site is in Montgomery County, but also the City of Houston’s Extra-Territorial Jurisdiction.
Detention Pond Requirements
The dry-bottom detention pond takes up approximately 5 of the 60 acres – or one twelfth of the site. Assuming it’s 12 feet deep, it would hold a foot of rain falling on the entire site. The new minimum recommendation for a site this size in Harris County and the City is .65 acre feet of detention per acre. That would be about 40 acre-feet of detention, which a pond 8 feet deep would hold.
Because the construction site is closed, and the plans I have don’t specify depth, it’s hard to say exactly how much capacity the detention pond has. But I’m guessing it’s deep enough to meet the new minimum requirements under Atlas 14. I say that judging by the height of the pond walls compared to the pipes leading into it.
I would expect no less from a public school system.
Posted by Bob Rehak on 7/12/2021
1413 Days after Hurricane Harvey