The San Jacinto River Authority (SJRA) will hold an initial public meeting tomorrow night to discuss its Flood Forecasting and Reservoir Operations Tool project.
Date: Thursday, October 24, 2019
Time: 6:00 p.m.
Place: SJRA General and Administrative Building Board Room, 1577 Dam Site Road, Conroe, Texas, 77304
Objectives of Forecasting Tool
The SJRA hopes to develop a tool that can:
Predict peak release rates of storm water from Lake Conroe
Anticipate peak water levels in Lake Conroe during rainfall events based on weather forecasts, observed rainfall, lake levels, and other data
Improve communication with Offices of Emergency Management and the public during storms.
Need for Faster, Better Information
“Getting information out as early as possible is essential during potential floods,” said Chuck Gilman, Director of Water Resources and Flood Management for the SJRA.
“The Flood Forecasting and Reservoir Operations Tool will take data from across the region and analyze it utilizing a model of the Lake Conroe Watershed to make predictions regarding flood threats. That will help us provide timely, accurate information for people to make decisions to protect themselves, their families, and property,” he added.
The gates at Lake Conroe can release water at up too 150,000 CFS. During Harvey they released almost 80,000 CFS.
During Hurricane Harvey, many people lost vehicles and valuables that could easily have been saved by driving them to higher ground if they had had more warning time. This project should help with that.
Available by Fall 2020
The Project will complete in fall 2020. A written technical memorandum will summarize recommendations for the tool.
The Texas Water Development Board (TWDB) and SJRA will jointly fund the project. TWDB offers grants to political subdivisions in Texas for evaluation of structural and nonstructural solutions to flooding problems and flood protection planning.
To Offer Input
Anyone interested may attend the meeting to express their views with respect to the project.
Questions or requests for additional information may be directed to:
Matt Barrett, P.E.
Division Engineer
SJRA
1577 Dam Site Road
Conroe, Texas 77304
Telephone (936) 588-3111
If you plan to speak, contact Matt Barrett either in writing or by telephone in advance of the meeting. If you cannot attend but have views you would like to share, contact Barrett today.
For additional information on SJRA, visit www.sjra.net.
Posted by Bob Rehak on 10/23/2019
785 Days after Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2019/04/LC-Dam-e1719277556742.jpg?fit=1200%2C549&ssl=15491200adminadmin2019-10-23 12:44:372019-10-23 16:18:51SJRA To Hold Meeting Thursday at 6 p.m. To Discuss New Flood Forecasting Tool
A week after J. Carey Gray, a lawyer representing Perry Homes’ subsidiaries and contractors, promised the Mayor of Houston that his clients would move as quickly as possible to complete Woodridge detention ponds, there still has been no excavation activity at the job site. And in fact, according to Jeff Miller, an Elm Grove resident who visited the site today, much of the material and equipment that had been on site are now gone.
Lack of Detention Implicated in Two Floods
Twice in four months, Elm Grove and North Kingwood Forest flooded severely when water from Perry Homes’ troubled Woodridge Village development overflowed into the streets of those communities immediately south and east of Woodridge.
Before the May flood, Perry had clearcut virtually the entire 268 acres, but installed only 7% of the detention.
Before the September flood, they had substantially completed only one more pond, bringing the total to 23% of the planned detention.
Percentage capacity of the five planned detention ponds on the Woodridge Village construction site as measured in acre feet. To date, only S1 and S2 are substantially complete.
So it’s not too surprising that the completed detention ponds overflowed in heavy rains.
It was like trying to store 100 gallons of water in a 23 gallon container.
Excavation Work on Detention Ponds Stopped for Two Months
As the pictures below show, there’s one piece of excavation equipment on the northern portion of the site and it hasn’t moved for about a month.
Looking west at northwestern section of Woodridge Village from helicopter more than a month ago, on 9/21/2019, two days after Imelda. Note the yellow excavator with its bucket resting on the ground in the middle of the frame toward the tree line on the right.Note the same excavator in the same place in the same position at the left of the frame. Photo taken 10/16/2019 from opposite direction, looking east.The foreground is where detention pond N1 should be. But the pond has not yet been started.According to the LJA Engineering report, it should have been excavated as part of the first phase of development.
Eight days later, you can see the same equipment still in the same place. However, it appears that two other pieces are now parked with it.
Photo taken by Jeff Miller on 10/22/2019 shows excavator in same photo it was photographed in on 9/21/2019, a month earlier.
Only Modest Repair Work on Ponds Since August
Resident Jeff Miller reported that an excavator removed some eroded sediment out of one completed pond (S1) after Imelda. Below is the photo he took on 10/6/2019. However, this was repair work, not newexcavation work.
According to the LJA Engineering Drainage Impact Analysis, Table 3, Phase 1 of this development was to have FOUR detention ponds installed: N-1 and N-2 (regraded pilot channel) on the north, S-1 and S-2 on the South.
However, no new detention capacity exists on the northern section which has the steepest slope and the largest surface area. It was to provide 77% of the total detention.
N-1 and N-2 should provide 62% of the detention capacity. However, N-1 doesn’t exist. N-2 is not fully excavated. And N-3, which will provide another 15% is only a distant dream.
Hundreds of Families Remain at Risk
The lack of progress on detention places hundreds of families at risk as we slog our way through another 5 weeks of hurricane season. The season ends on November 30. But flood-weary residents also remain wary of non-tropical storms, such as Tax Day, Memorial Day, and May 7th this year. In the moist, Gulf-coast region, heavy storms can strike any time of year.
Now, there’s an iron-clad contract if I ever saw one! However, as of October 22, 2019, no residents that I consulted around the site had seen any workers recently. Mr. J. Carey Gray, Attorney at Law, dated his letter October 17th.
According to resident Nancy Vera who lives immediately south of the construction site, there has been no recent construction activity anywhere on the site that she or her family can see.
Gretchen Smith who can see the site from her front yard in Porter has seen no workers.
Jeff Miller visits the site almost daily to check progress or non-progress of work. He had not seen any workers lately either. Moreover, he said that much of the materials and heavy equipment that had been stored on site appear to be gone.
Maybe Mr. Gray needs to consult with Larry, the Cable Guy.
Posted by Bob Rehak on 10/23/2019, with help from Jeff Miller, Nancy Vera, and Gretchen Dunlap-Smith
785 Days since Hurricane Harvey and 34 since Imelda
All thoughts in this post represent my opinions on matters of public policy 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/2019/10/Excavator-Highlighted.jpg?fit=1500%2C1000&ssl=110001500adminadmin2019-10-23 00:11:302019-10-23 00:12:40One Week After Town Hall, Still No New Work on Woodridge Village Detention Ponds
Recently, I flew up the West Fork of the San Jacinto in a helicopter and got some pictures of the new 91-acre Northpark Woods subdivision. It’s just north of Northpark, between Sorters Road and the West Fork. Where thousands of trees once stood, I saw a massive gash in the landscape. But when reviewing my photos, something else jumped out at me – the density of this subdivision and the percent of impervious cover it will have. Both the loss of trees and the higher percentage of impervious cover increase flood risk.
As we saw Perry Homes do with Woodridge Village, this developer clear-cut the land. Trees often don’t survive the heavy equipment used in construction. And working around them consumes time. So builders find it simpler and cheaper to let homeowners replant them. However, regrowth can take decades, especially in heavily compacted soil which stunts tree growth.
But the tiny lots in this subdivision mean buyers may never even attempt to replant trees. There’s not much room for them.
More Impervious Cover Per Lot
Developments with tiny lots have more impervious cover (roofs, driveways, streets, sidewalks) as a percentage of the lot. The higher the percentage of impervious cover, the faster runoff accumulates, and the higher flood waters peak.
Photographically, it looks like this. A civil engineer told me that homes like these can have 80% impervious cover.
Note how closely the homes are spaced. In the second row of 7 homes, you can see that garages take up almost the entire width of each home except for a front door.Driveways will eliminate most of the front yardsas you can see on the developer’s web site.Looking NW. Sorters Road is on the right on a diagonal.Compare the density and tree cover in the foreground to that of Oakhurst, beyond the tree line in the far background. Looking NE toward Oakhurst.Also note the huge erosion holes downstream of the weirs in the ditch. Those will soon be in homebuyers back yards.Note the proximity to the San Jacinto West Fork (as well as abandoned and active sand mines), in the background. Looking west toward West Fork and the Hallett Mine.Here, you can also see how that ditch erosion is already threatening the road along its side.
A Denver-based developer plans to sell these as starter homes. More experienced buyers ask tougher questions. When I bought a house in Dallas at a very young age, I didn’t even know what a flood plain was. Nor did I understand how inexact a science flood plain mapping can be. Or how quickly an upstream development can increase flooding downstream.
Within three years, I went from being two feet above the hundred year flood plain to ten feet below it.
Approximate outlines of development in white over MoCo floodplain map. Virtually half of the Northpark Woods subdivision is in floodplain (500year=brown, 100-year=aqua). New upstream developments have decreased the time of accumulation and increased flood peaks. See first graph above. Caution: the data behind these flood maps is from the 1980s and being updated.
The detention ponds on this site occupy the 100-year floodplain (aqua). About half the homes will be in the 500-year floodplain (brown). But keep in mind, the data on which this flood map is based has not been updated since the 1980s. So the real floodplains most likely cover far more area than shown here. Don’t be fooled by the 2014 date. The background image was updated then, not the height of the floods.
As long as less knowledgable people keep buying such homes in locations like these, developers will keep throwing them up.
Ironically, about three miles downstream, Harris County Flood Control is buying out another high density development near the West Fork. And Tammy Gunnels, only a quarter miles downstream – and in the 500-year flood plain – has now flooded 12 times in the last ten years.
The legal principle of “Caveat emptor” (Buyer beware) means that the buyer alone is responsible for checking the quality and suitability of goods before a purchase is made. Caveat emptor still applies when buying a house.
Most young people would not think to question when flood maps were last updated, especially if they see a date of 2014.
The data behind the flood map above is currently being updated as part of the San Jacinto River Basin Study by Harris County Flood Control, Montgomery County, SJRA and City of Houston. As of this writing, hydrologic and hydraulic models have been developed. Consultants are now calibrating those to known high water marks, such as those in this 2018 USGS study.
The USGS study shows that Hurricane Harvey at the Highway 99 gage (closest upstream gage) had an annual exceedance probability (AEP) of 2.4.
It could take years for that San Jacinto River Basin study to go through required public review and approval processes. Expect developers and other landowners to fight new maps every step of the way. More realistic flood maps will mean higher development costs for property that suddenly finds itself in a floodplain. And some properties could end up in floodways and be totally undevelopable. In the meantime, caveat emptor.
Posted by Bob Rehak on 10.22.2019
784 Days since Hurricane Harvey
The thoughts expressed in this post represent my opinions on matters of public policy 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/2019/10/EF-WF-Aerial_585.jpg?fit=1500%2C1000&ssl=110001500adminadmin2019-10-21 22:24:412019-10-22 08:58:37Where Thousands of Trees Once Stood: The New Woodless Northpark Woods
SJRA To Hold Meeting Thursday at 6 p.m. To Discuss New Flood Forecasting Tool
The San Jacinto River Authority (SJRA) will hold an initial public meeting tomorrow night to discuss its Flood Forecasting and Reservoir Operations Tool project.
Objectives of Forecasting Tool
The SJRA hopes to develop a tool that can:
Need for Faster, Better Information
“Getting information out as early as possible is essential during potential floods,” said Chuck Gilman, Director of Water Resources and Flood Management for the SJRA.
“The Flood Forecasting and Reservoir Operations Tool will take data from across the region and analyze it utilizing a model of the Lake Conroe Watershed to make predictions regarding flood threats. That will help us provide timely, accurate information for people to make decisions to protect themselves, their families, and property,” he added.
During Hurricane Harvey, many people lost vehicles and valuables that could easily have been saved by driving them to higher ground if they had had more warning time. This project should help with that.
Available by Fall 2020
The Project will complete in fall 2020. A written technical memorandum will summarize recommendations for the tool.
The Texas Water Development Board (TWDB) and SJRA will jointly fund the project. TWDB offers grants to political subdivisions in Texas for evaluation of structural and nonstructural solutions to flooding problems and flood protection planning.
To Offer Input
Questions or requests for additional information may be directed to:
If you plan to speak, contact Matt Barrett either in writing or by telephone in advance of the meeting. If you cannot attend but have views you would like to share, contact Barrett today.
For additional information on SJRA, visit www.sjra.net.
Posted by Bob Rehak on 10/23/2019
785 Days after Hurricane Harvey
One Week After Town Hall, Still No New Work on Woodridge Village Detention Ponds
A week after J. Carey Gray, a lawyer representing Perry Homes’ subsidiaries and contractors, promised the Mayor of Houston that his clients would move as quickly as possible to complete Woodridge detention ponds, there still has been no excavation activity at the job site. And in fact, according to Jeff Miller, an Elm Grove resident who visited the site today, much of the material and equipment that had been on site are now gone.
Lack of Detention Implicated in Two Floods
Twice in four months, Elm Grove and North Kingwood Forest flooded severely when water from Perry Homes’ troubled Woodridge Village development overflowed into the streets of those communities immediately south and east of Woodridge.
So it’s not too surprising that the completed detention ponds overflowed in heavy rains.
Excavation Work on Detention Ponds Stopped for Two Months
Where’s Larry the Cable Guy when you need him? He could “git-r-done.”
As the pictures below show, there’s one piece of excavation equipment on the northern portion of the site and it hasn’t moved for about a month.
Eight days later, you can see the same equipment still in the same place. However, it appears that two other pieces are now parked with it.
Only Modest Repair Work on Ponds Since August
Resident Jeff Miller reported that an excavator removed some eroded sediment out of one completed pond (S1) after Imelda. Below is the photo he took on 10/6/2019. However, this was repair work, not new excavation work.
Four Detention Ponds Promised as Part of Phase 1
According to the LJA Engineering Drainage Impact Analysis, Table 3, Phase 1 of this development was to have FOUR detention ponds installed: N-1 and N-2 (regraded pilot channel) on the north, S-1 and S-2 on the South.
N-1 and N-2 should provide 62% of the detention capacity. However, N-1 doesn’t exist. N-2 is not fully excavated. And N-3, which will provide another 15% is only a distant dream.
Hundreds of Families Remain at Risk
The lack of progress on detention places hundreds of families at risk as we slog our way through another 5 weeks of hurricane season. The season ends on November 30. But flood-weary residents also remain wary of non-tropical storms, such as Tax Day, Memorial Day, and May 7th this year. In the moist, Gulf-coast region, heavy storms can strike any time of year.
J. Carey Gray’s Promise
Last week, J. Carey Gray, Attorney at Law, made a promise to the City of Houston’s top lawyer, Mayor Sylvester Turner. Gray said, “To the extent possible, we will attempt to begin each project as quickly as plans can be completed and approved.”
Now, there’s an iron-clad contract if I ever saw one! However, as of October 22, 2019, no residents that I consulted around the site had seen any workers recently. Mr. J. Carey Gray, Attorney at Law, dated his letter October 17th.
According to resident Nancy Vera who lives immediately south of the construction site, there has been no recent construction activity anywhere on the site that she or her family can see.
Gretchen Smith who can see the site from her front yard in Porter has seen no workers.
Jeff Miller visits the site almost daily to check progress or non-progress of work. He had not seen any workers lately either. Moreover, he said that much of the materials and heavy equipment that had been stored on site appear to be gone.
Maybe Mr. Gray needs to consult with Larry, the Cable Guy.
Posted by Bob Rehak on 10/23/2019, with help from Jeff Miller, Nancy Vera, and Gretchen Dunlap-Smith
785 Days since Hurricane Harvey and 34 since Imelda
All thoughts in this post represent my opinions on matters of public policy and safety. They are protected by the First Amendment of the US Constitution and the Anti-SLAPP Statute of the Great State of Texas.
Where Thousands of Trees Once Stood: The New Woodless Northpark Woods
Recently, I flew up the West Fork of the San Jacinto in a helicopter and got some pictures of the new 91-acre Northpark Woods subdivision. It’s just north of Northpark, between Sorters Road and the West Fork. Where thousands of trees once stood, I saw a massive gash in the landscape. But when reviewing my photos, something else jumped out at me – the density of this subdivision and the percent of impervious cover it will have. Both the loss of trees and the higher percentage of impervious cover increase flood risk.
Inner-City Density Comes to Suburban MoCo
I previously wrote about Northpark Woods in a post called “Living on the Edge or the Death of Caution.”
As we saw Perry Homes do with Woodridge Village, this developer clear-cut the land. Trees often don’t survive the heavy equipment used in construction. And working around them consumes time. So builders find it simpler and cheaper to let homeowners replant them. However, regrowth can take decades, especially in heavily compacted soil which stunts tree growth.
More Impervious Cover Per Lot
Developments with tiny lots have more impervious cover (roofs, driveways, streets, sidewalks) as a percentage of the lot. The higher the percentage of impervious cover, the faster runoff accumulates, and the higher flood waters peak.
Graphically, it looks like this.
Aerial Images Taken on 10.2.19
Photographically, it looks like this. A civil engineer told me that homes like these can have 80% impervious cover.
In Shenandoah, TX, upstream from here, the City has allowed up to 10 lots per acre with 90% impervious cover!
Shifting Flood Plains
A Denver-based developer plans to sell these as starter homes. More experienced buyers ask tougher questions. When I bought a house in Dallas at a very young age, I didn’t even know what a flood plain was. Nor did I understand how inexact a science flood plain mapping can be. Or how quickly an upstream development can increase flooding downstream.
The detention ponds on this site occupy the 100-year floodplain (aqua). About half the homes will be in the 500-year floodplain (brown). But keep in mind, the data on which this flood map is based has not been updated since the 1980s. So the real floodplains most likely cover far more area than shown here. Don’t be fooled by the 2014 date. The background image was updated then, not the height of the floods.
Ironically, about three miles downstream, Harris County Flood Control is buying out another high density development near the West Fork. And Tammy Gunnels, only a quarter miles downstream – and in the 500-year flood plain – has now flooded 12 times in the last ten years.
Buyer Beware
Among the many other dangers of building in this location: river migration. The San Jacinto West Fork is migrating toward these homes at the rate of about 20 feet per year. When the river captures the abandoned sand pits next to these homes, it could migrate much faster.
The legal principle of “Caveat emptor” (Buyer beware) means that the buyer alone is responsible for checking the quality and suitability of goods before a purchase is made. Caveat emptor still applies when buying a house.
The data behind the flood map above is currently being updated as part of the San Jacinto River Basin Study by Harris County Flood Control, Montgomery County, SJRA and City of Houston. As of this writing, hydrologic and hydraulic models have been developed. Consultants are now calibrating those to known high water marks, such as those in this 2018 USGS study.
The USGS study shows that Hurricane Harvey at the Highway 99 gage (closest upstream gage) had an annual exceedance probability (AEP) of 2.4.
It could take years for that San Jacinto River Basin study to go through required public review and approval processes. Expect developers and other landowners to fight new maps every step of the way. More realistic flood maps will mean higher development costs for property that suddenly finds itself in a floodplain. And some properties could end up in floodways and be totally undevelopable. In the meantime, caveat emptor.
Posted by Bob Rehak on 10.22.2019
784 Days since Hurricane Harvey
The thoughts expressed in this post represent my opinions on matters of public policy and safety. They are protected by the First Amendment of the US Constitution and the Anti-SLAPP Statute of the Great State of Texas.