For the record, this morning, the SJRA resumed lowering Lake Conroe just three days before the scheduled end of its Spring seasonal release. As of 1PM, the SJRA is releasing 1581 cubic feet per second. Recent rains raised the lake level more than a half foot from the target of 200 feet to 200.53 feet.
Source SJRA.net as of approximately 11 a.m. on May 29, 2020.
SJRA Coordinated with CoH
The lake had risen to approximately 200.4 feet for the last two weeks of May. And, when heavy rains entered the forecast, readers began to ask whether SJRA would lower it to 200 again. However, SJRA did not resume lowering at that time.
Reportedly, the City of Houston was worried about overloading Lake Houston at a time when:
Dam repairs were in progress
Heavy rainfall was in the forecast
So the SJRA held water back.
What 500 CFS looks like. Photographed 7/31/2018, during a tour of the Lake Conroe Dam.The current release is three times this rate.
According to sources, the Coastal Water Authority has opened its gates on Lake Houston and is coordinating release rates with the SJRA so as not to flood downstream residents.
Exact Text of Spring Lake Lowering Policy
For the record, here is the official SJRA lake lowering policy renewed with some modifications after months of divisive debate. Lake Houston residents wanted the extra buffer against flooding. Lake Conroe residents claimed there was no proof it worked. They also claimed that it was lowering their property values and destroying their tax base.
In the Spring, the policy calls for:
“Beginning April 1, release only an amount of water from Lake Conroe to create a one foot capacity to catch rainfall and storm runoff (from 201’ mean sea level to 200’ msl). Recapture of lake level beginning June 1.”
Average Lake Level By Month for 46 Years
Also note that the lake level rarely reaches 201. The average varies each month depending on rainfall and evaporation. So when Lake Conroe reached 200.53, it exceeded the norm.
Lake Conroe seasonal levels by month. Source: SJRA
We need to watch this closely. In 2.5 days, this release should stop until the SJRA resumes seasonal releases on August 1. Please report any flooding through the contact page on this web site.
Beginning August 1, release only an amount of water from Lake Conroe to create a one foot capacity to catch rainfall and storm runoff (from 201’ msl to 200’ msl). After September 1, increase capacity an additional six inches (from 200’ msl to 199.5’ msl). If a named storm is predicted to impact our region, the COH may initiate an additional release of six inches (to 199’ msl) by notifying SJRA in writing of their call for release. Recapture beginning October 1.
Posted by Bob Rehak on 5/29/2020
1004 Days after Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2020/05/IMG_0929.jpeg?fit=1280%2C960&ssl=19601280adminadmin2020-05-29 14:21:132020-05-29 14:21:32SJRA Resumes Seasonal Release 3 Days Before Scheduled End
Disaster Recovery Corporation, a contractor for the City of Houston will soon begin debris removal on the San Jacinto East Fork.
Scope of Work
The scope of this particular phase of debris removal extends from just north of the southern tip of Lake Houston Park to about halfway up the east side of the 5000 acre park. See the start and stop points on the satellite image below.
The City of Houston should begin debris removal on the east side of Lake Houston Park next week.
The distance covered equals 2 miles as crow flies or 3 miles as the fish swims.
Debris Includes…
Here are FEMA guidelines for debris removal. Debris can include trees, sunken boats, old tires, vehicles, and other things washed downstream in floods. It is basically any debris in the water, or below the surface at a depth that is equal to the maximum draft level of the largest vessel that would use the waterway plus 2 feet. Debris also includes trees that are leaning or that pose a threat to public safety.
Beginning First Week in June
Work should start the first week in June. Authorities eventually expect the work to extend up to the Harris County line at FM1485 near the extension of the Grand Parkway.
The trees pose hazards to navigation and can form logjams that back water up in floods, threatening homes and businesses. They also can get hung up on bridge supports and the Lake Houston Dam, threatening infrastructure.
During Harvey, trees swept downstream and caught up in the supports for the Union Pacific and the southbound Highway 59 bridges over the West Fork in Humble. Both bridges had to be replaced. Trees also blocked flow at the FM1960 bridge and the rail bridge in Lake Houston.
Trees enter the waterway when floodwaters undermine river banks or simply rip trees out by their roots.
Downed trees on West Fork after Hurricane Harvey flood. Photo taken September 14, 2017Dead tree removal on Lake Houston in June 2018.This pontoon carried dead trees as well as fencing that had been swept into the river. September 2018.
Posted by Bob Rehak on 5/29/2020
1004 Days after Hurricane Harvey and 253 since Imelda
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2018/09/SJR_525_053.jpg?fit=1800%2C1200&ssl=112001800adminadmin2020-05-29 11:24:462020-05-29 11:31:22City of Houston Contractors to Begin East Fork Debris Removal
Residents of Harris County and surrounding areas now have and easy way to assess flood potential near them in near real time. It’s called the Harris County Flood Warning System website. It offers near-real-time information from 100+ gages on major streams and rivers throughout the entire region.
Below, you can see part of the welcome screen, zoomed into the North Houston area. It shows the amount of rainfall at each gage.
Most of north Harris County received less than an inch of rainfall yesterday. However, areas to the west, north, and south received up to three inches. Areas upstream from Kingwood received five to six times more rainfall that the Lake Houston Area.
Rainfall patterns like that can lull people into a false sense of security because flooding originates upstream and works its way down.
Given the severity of yesterday’s storms, several people asked last night and this morning, “What is the potential for flooding?” The Harris County Flood Warning System provides answers. Here’s how to use it for maximum effect.
Customized Alerts from Flood Warning System
First, note that The Flood Warning System allows you to create an account and customize alerts. While not necessary, it helps reduce extraneous information in emergencies, so you only receive messages that affect you.
For instance, the San Jacinto West Fork, Spring Creek and Cypress Creek affect those living in the Humble/Kingwood area. All three converge just west of the US59 bridge. So you could sign up for alerts only from gages in those areas.
Data-Driven Mapping System
Note that the Flood Warning System lets you select several map view options to help you understand conditions near you as well as upstream. For instance, if you click “Watersheds” and “Channel Status,” you can see:
Which watershed you live in
The near-real-time status of gages in that area
Where flood danger or possible flooding exists
Harris County Flood Warning System as of 5/28/2020, 11am.With Channel Status and Watershed options selected.
Drilling Down to Areas of Interest
From there, you can click on gages of interest. The green squares indicate “no flooding danger.” The yellow triangles mean “potential danger.” Red means “flooding.”
So, clicking on the yellow triangle by Shenandoah in the Spring Creek Watershed lets me investigate what’s happening at that gage. See below.
Source: Harris County Flood Warning System at 11:13 a.m. on 5/28/2020.
From this information, I can see that the channel is higher than normal, but still well within its banks. The top of bank (TOB) is at 156.26 feet. But the current water level is only at 154.33 feet. More important, I can see from the graph that the water level has peaked and is trending down.
With all other reporting stations in my watershed showing “green,” I can breath easy. Unless we get major rainfall upstream this afternoon. After all, this creek rose 3.5 feet yesterday after receiving about 2 inches of rain upstream. Today, soils are highly saturated and the creek is only about 2 feet from coming out of its banks. Another two inches of rain could cause flooding. (See forecast at bottom of this post.)
Other Valuable Features
Among other features, Harris County’s Flood Warning System offers:
Historical data so that you can compare current water level data to past floods that may have threatened your home.
Rainfall alarms that tell you when particularly heavy downpours have occurred near you that could trigger street or stream flooding.
Inundation mapping that shows the extent of flooding during flood events.
Color-coded channel status maps to show you at a glance where streams are flooding
Links to weather alerts
All in all, Harris County Flood Control District has built a powerful tool with its Flood Warning System. It’s intuitive, uncluttered and easy to use, giving you the information you need, when you need it, where you need it, in the form you need it.
It’s fun to explore all the options. If it rains again this afternoon, use the opportunity to teach your family how to use it.
With the information on this web site, Lake Houston Area residents who flooded during Harvey could have seen the 80,000 cubic feet per second released from Lake Conroe barreling down the West Fork toward them…despite the breakdown in the emergency warning system. They could have evacuated sooner. They could have saved vehicles, valuables, and in some cases even lives.
Everyone should become familiar with the Flood Warning System, learn how to use it and bookmark it. If I were a science teacher in this area, learning how to use this site would become part of my curriculum.
Unsettled Weather Continues Today
Chances of additional heavy rainfall in the Lake Houston Area are lower today than yesterday. However, potential for scattered thunderstorms by early afternoon remains, according to Jeff Lindner, Harris County meteorologist.
Lindner adds, “…given the developing instability and cold air aloft, large hail and gusty winds are possible. NOAA’s Storm Prediction Center (SPC) does have nearly all of the area in a “marginal” risk for severe storms this afternoon with a higher threat to our west across southwest and south central TX.”
It will be hard to predict the exact location of these storms, says Lindner. “We could see some additional very heavy rainfall with the storms this afternoon (1-2 inches) in an hour or less. And while grounds are becoming saturated from all the recent rain, only street flooding is expected.”
“With that said, upper Spring and upper Little Cypress Creeks are elevated and should heavy rains impact NW Harris County, there could be some minor lowland flooding along the headwaters of those channels.”
“Upper level high pressure begins to build into the area Friday and will gain a foothold over the region this weekend into next week. Expect rain chances to taper back to only 10-20%. We can probably cut chances completely by Sunday,” says Lindner.
Posted by Bob Rehak on 5/28/2020
1003 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2020/05/Channel-Status-5.28.jpg?fit=1500%2C906&ssl=19061500adminadmin2020-05-28 13:36:092020-05-28 13:47:23Easy Way to Assess Your Flood Potential in Near Real Time
SJRA Resumes Seasonal Release 3 Days Before Scheduled End
For the record, this morning, the SJRA resumed lowering Lake Conroe just three days before the scheduled end of its Spring seasonal release. As of 1PM, the SJRA is releasing 1581 cubic feet per second. Recent rains raised the lake level more than a half foot from the target of 200 feet to 200.53 feet.
SJRA Coordinated with CoH
The lake had risen to approximately 200.4 feet for the last two weeks of May. And, when heavy rains entered the forecast, readers began to ask whether SJRA would lower it to 200 again. However, SJRA did not resume lowering at that time.
Reportedly, the City of Houston was worried about overloading Lake Houston at a time when:
So the SJRA held water back.
According to sources, the Coastal Water Authority has opened its gates on Lake Houston and is coordinating release rates with the SJRA so as not to flood downstream residents.
Exact Text of Spring Lake Lowering Policy
For the record, here is the official SJRA lake lowering policy renewed with some modifications after months of divisive debate. Lake Houston residents wanted the extra buffer against flooding. Lake Conroe residents claimed there was no proof it worked. They also claimed that it was lowering their property values and destroying their tax base.
In the Spring, the policy calls for:
Average Lake Level By Month for 46 Years
Also note that the lake level rarely reaches 201. The average varies each month depending on rainfall and evaporation. So when Lake Conroe reached 200.53, it exceeded the norm.
We need to watch this closely. In 2.5 days, this release should stop until the SJRA resumes seasonal releases on August 1. Please report any flooding through the contact page on this web site.
Text of Fall Policy
The fall seasonal lowering coincides with the peak of hurricane season. The SJRA Fall seasonal lowering policy states:
Posted by Bob Rehak on 5/29/2020
1004 Days after Hurricane Harvey
City of Houston Contractors to Begin East Fork Debris Removal
Disaster Recovery Corporation, a contractor for the City of Houston will soon begin debris removal on the San Jacinto East Fork.
Scope of Work
The scope of this particular phase of debris removal extends from just north of the southern tip of Lake Houston Park to about halfway up the east side of the 5000 acre park. See the start and stop points on the satellite image below.
The distance covered equals 2 miles as crow flies or 3 miles as the fish swims.
Debris Includes…
Here are FEMA guidelines for debris removal. Debris can include trees, sunken boats, old tires, vehicles, and other things washed downstream in floods. It is basically any debris in the water, or below the surface at a depth that is equal to the maximum draft level of the largest vessel that would use the waterway plus 2 feet. Debris also includes trees that are leaning or that pose a threat to public safety.
Beginning First Week in June
Work should start the first week in June. Authorities eventually expect the work to extend up to the Harris County line at FM1485 near the extension of the Grand Parkway.
Debris Removal to Date
Debris removal to date in other places on the East and West Forks and their tributaries has consisted mainly of the removal of downed trees. On Lake Houston, debris removal began almost exactly two years ago.
The trees pose hazards to navigation and can form logjams that back water up in floods, threatening homes and businesses. They also can get hung up on bridge supports and the Lake Houston Dam, threatening infrastructure.
During Harvey, trees swept downstream and caught up in the supports for the Union Pacific and the southbound Highway 59 bridges over the West Fork in Humble. Both bridges had to be replaced. Trees also blocked flow at the FM1960 bridge and the rail bridge in Lake Houston.
Trees enter the waterway when floodwaters undermine river banks or simply rip trees out by their roots.
Posted by Bob Rehak on 5/29/2020
1004 Days after Hurricane Harvey and 253 since Imelda
Easy Way to Assess Your Flood Potential in Near Real Time
Residents of Harris County and surrounding areas now have and easy way to assess flood potential near them in near real time. It’s called the Harris County Flood Warning System website. It offers near-real-time information from 100+ gages on major streams and rivers throughout the entire region.
Below, you can see part of the welcome screen, zoomed into the North Houston area. It shows the amount of rainfall at each gage.
Most of north Harris County received less than an inch of rainfall yesterday. However, areas to the west, north, and south received up to three inches. Areas upstream from Kingwood received five to six times more rainfall that the Lake Houston Area.
Rainfall patterns like that can lull people into a false sense of security because flooding originates upstream and works its way down.
Given the severity of yesterday’s storms, several people asked last night and this morning, “What is the potential for flooding?” The Harris County Flood Warning System provides answers. Here’s how to use it for maximum effect.
Customized Alerts from Flood Warning System
First, note that The Flood Warning System allows you to create an account and customize alerts. While not necessary, it helps reduce extraneous information in emergencies, so you only receive messages that affect you.
For instance, the San Jacinto West Fork, Spring Creek and Cypress Creek affect those living in the Humble/Kingwood area. All three converge just west of the US59 bridge. So you could sign up for alerts only from gages in those areas.
Data-Driven Mapping System
Note that the Flood Warning System lets you select several map view options to help you understand conditions near you as well as upstream. For instance, if you click “Watersheds” and “Channel Status,” you can see:
Drilling Down to Areas of Interest
From there, you can click on gages of interest. The green squares indicate “no flooding danger.” The yellow triangles mean “potential danger.” Red means “flooding.”
So, clicking on the yellow triangle by Shenandoah in the Spring Creek Watershed lets me investigate what’s happening at that gage. See below.
From this information, I can see that the channel is higher than normal, but still well within its banks. The top of bank (TOB) is at 156.26 feet. But the current water level is only at 154.33 feet. More important, I can see from the graph that the water level has peaked and is trending down.
With all other reporting stations in my watershed showing “green,” I can breath easy. Unless we get major rainfall upstream this afternoon. After all, this creek rose 3.5 feet yesterday after receiving about 2 inches of rain upstream. Today, soils are highly saturated and the creek is only about 2 feet from coming out of its banks. Another two inches of rain could cause flooding. (See forecast at bottom of this post.)
Other Valuable Features
Among other features, Harris County’s Flood Warning System offers:
All in all, Harris County Flood Control District has built a powerful tool with its Flood Warning System. It’s intuitive, uncluttered and easy to use, giving you the information you need, when you need it, where you need it, in the form you need it.
It’s fun to explore all the options. If it rains again this afternoon, use the opportunity to teach your family how to use it.
With the information on this web site, Lake Houston Area residents who flooded during Harvey could have seen the 80,000 cubic feet per second released from Lake Conroe barreling down the West Fork toward them…despite the breakdown in the emergency warning system. They could have evacuated sooner. They could have saved vehicles, valuables, and in some cases even lives.
Everyone should become familiar with the Flood Warning System, learn how to use it and bookmark it. If I were a science teacher in this area, learning how to use this site would become part of my curriculum.
Unsettled Weather Continues Today
Chances of additional heavy rainfall in the Lake Houston Area are lower today than yesterday. However, potential for scattered thunderstorms by early afternoon remains, according to Jeff Lindner, Harris County meteorologist.
Lindner adds, “…given the developing instability and cold air aloft, large hail and gusty winds are possible. NOAA’s Storm Prediction Center (SPC) does have nearly all of the area in a “marginal” risk for severe storms this afternoon with a higher threat to our west across southwest and south central TX.”
It will be hard to predict the exact location of these storms, says Lindner. “We could see some additional very heavy rainfall with the storms this afternoon (1-2 inches) in an hour or less. And while grounds are becoming saturated from all the recent rain, only street flooding is expected.”
“With that said, upper Spring and upper Little Cypress Creeks are elevated and should heavy rains impact NW Harris County, there could be some minor lowland flooding along the headwaters of those channels.”
“Upper level high pressure begins to build into the area Friday and will gain a foothold over the region this weekend into next week. Expect rain chances to taper back to only 10-20%. We can probably cut chances completely by Sunday,” says Lindner.
Posted by Bob Rehak on 5/28/2020
1003 Days since Hurricane Harvey