Tag Archive for: Lake Conroe

Why Lake Houston Is So Full in a Drought

I flew over Lake Houston this morning in a helicopter. I expected to see the barren lake bed in places like you could during the 2011 drought. However, much to my surprise, the lake was virtually full.

Coastal Water Authority Shows Lake Down Only 6 Inches

The Coastal Water Authority, which manages the lake for the City of Houston, shows Lake Houston is only down a half foot.

Coastal Water Authority dashboard as of 8/12/23 at 6PM

Water was lapping at the edge of the the spillway.

Lake Houston Dam spillway. Photo take 8/12/23 at approximately 10am.

SJRA Shows Lake Conroe Down About 15 Inches

Lake Conroe is down about 15 inches from its normal conservation pool (the target level). And it hasn’t released any water downstream toward Lake Houston in months. The SJRA’s dashboard shows

SJRA Dashboard on 8/12/23 at 6PM.

Luce Bayou InterBasin Transfer Canal Bringing the Water

So what’s keeping Lake Houston full? What is offsetting drought and evaporation?

A quick check of the gages on the Harris County flood warning system shows areas far upstream have gotten small amounts of rain. But the most water we saw moving all day was coming from the Trinity River via the Luce Bayou InterBasin transfer project.

Luce Bayou Inter-Basin transfer canal bringing water to Lake Houston from the Trinity River on 8/12/23 at 9 am.

Gages upstream from Lake Livingston, which captures water coming down the Trinity River from Dallas/Fort Worth, recorded approximately 11 inches of rain in June, July and August (to date).

Lake Conroe got enough rain to offset some evaporation but not enough to supply Montgomery and Harris Counties.

It’s nice to have backups for Lake Houston in a drought, especially widely scattered backups that can capture rain moving through different parts of the region.

Posted by Bob Rehak on 8/12/23

2174 Days since Hurricane Harvey

Lake Houston Gates Project Moves Closer to Reality

The Lake Houston Gates Project is moving closer to reality with breakthroughs on the benefit/cost ratio, funding and endorsements.

City of Houston Mayor Pro Tem Dave Martin and Chief Recovery Officer Stephen Costello provided updates on 2/27/23 at City Hall on the Lake Houston Gates Project. The wide-ranging, hour-long discussion covered several related topics. They included:

  • A critical path for construction
  • Dredging of the lake
  • Funding for gates and dredging
  • Several related engineering studies
  • A favorable ruling from FEMA on the Benefit-Cost Ratio
  • An endorsement to the area’s legislators by the Greater Houston Partnership.

Need For Gates

For those new to the area, the City of Houston has been pushing to add gates to the Lake Houston Dam ever since Harvey in 2017. Upstream, Lake Conroe’s gates can release 150,000 cubic feet per second (CFS). But Lake Houston’s can only release 10,000 CFS.

The disparity in discharge capacity complicates joint-reservoir-management and pre-release strategies designed to avoid flooding by reducing the water level in Lake Houston.

Lake Houston releases cannot keep up with Lake Conroe’s. And pre-releasing water from Lake Houston takes so long that storms can veer away during the lowering process, often resulting in wasted water. That’s an important consideration for a water-supply lake.

According to Martin and Costello, the gate project will:

• Serve as the first phase of a long-term effort to extend the life of the Dam
• Enable the rapid lowering of lake levels in advance of a flood
• Eliminate the need for a seasonal lowering of both Lake Houston and Lake Conroe
• Provide potential water-rights savings
• Protect an estimated 5,000 residential properties in the surrounding area
• Yield an estimated half billion dollars in economic benefits during the life of the project

Gates, Funding, BCR, Studies

Preliminary engineering studies evaluated about a dozen different alternatives for adding discharge capacity to Lake Houston. The City initially favored adding crest gates to the spillway portion of the dam.

However, the City discarded that idea as “too risky” after further study. The engineering company cautioned the City that it would have a difficult time finding contractors willing to risk modifying a 70-year old concrete dam. The potential liability was just too great. So the City then revisited adding various numbers of tainter gates to the eastern, earthen portion of the dam.

Because tainter gates exceeded FEMA’s funding, the City had initially focused on crest gates. But after investigating the safety issues, the City decided to seek more funding for tainter gates instead.

The City now recommends adding 11 tainter gates.

Recommended location for new tainter gates is next to old ones, not farther east as I conjectured earlier.

The picture below is slightly wider and shows more of how both halves of the dam come together.

If funding comes through, new gates would go in the upper right along the earthen portion of the dam, next to the old gates.
Funding Needs

FEMA initially set aside $50 million for the gates. Plus Harris County committed $20 million in the 2018 Flood Bond to attract FEMA’s match. But the latest construction estimates show eleven tainter gates could cost between $200 and $250 million.

After engineering and environmental studies, only $68.3 million in funding remains. That includes an earmark secured by Congressman Dan Crenshaw. So the City is seeking another $150 million from the State of Texas. Martin and Costello have made weekly trips to Austin so far during this session to line up support from legislators, committee chairs, and the Texas Division of Emergency Management.

Social Benefits Improve Benefit/Cost Ratio

All this is suddenly possible because of a favorable ruling from FEMA on the benefit-cost ratio (BCR).

For years, Houston had struggled to get the BCR for the gate project above 1.0 (the point at which benefits exceed costs). Usually, FEMA strictly interprets benefits as “avoided damages to structures.”

But Houston Mayor Sylvester Turner and Costello met with FEMA to argue that the problem was much bigger than damaged structures.

As a result, FEMA allowed the City to add the value of “social benefits” to the BCR. Social benefits can include such things as avoiding lost wages when businesses are destroyed; transportation disruptions that reduce the region’s productivity; reducing negative impacts on student achievement when schools are disrupted; and more.

The social-benefit ruling covers a number of City projects, not just the gates. It should also benefit other areas, especially rural ones.

Said Costello, “The minute the social benefits came in, everything was great.” Instead of struggling to reach 1.0, the City is now far above it.

Greater Houston Partnership Endorsement

With that out of the way, the Greater Houston Partnership wrote a powerful letter to state legislators seeking their support for the gate project. See below.

Greater Houston Partnership letter endorsing Lake Houston Gates. For a printable PDF, click here.

The Partnership includes business leaders from 900 member companies in the 12-county Houston Region.

Dredging Update

While pressing ahead with the gates project, the City is also working on a long-term dredging plan for the lake and working with the SJRA on sedimentation and sand-trap pilot projects.

The Texas Water Department Board (TWDB) has estimated sediment inflow to Lake Houston at about 380 acre-feet of material annually.

The lake has already lost more than 20,000 acre feet of capacity due to sedimentation. That worsens flooding. While the Federal Government supports efforts to improve Lake Houston now, the chances of getting more money in the future will be reduced – unless we can show that we’re at least keeping pace with annual sediment deposits.

Since Harvey, FEMA, the Army Corps, TWDB, and City of Houston have removed almost 4 million cubic yards of material from the lake at a cost of $226 million.

We have to prevent more sediment from coming downstream or dredge it after it gets here.

Stephen Costello, City of Houston Chief Recovery Officer

The City is currently lobbying for another $50 million for maintenance dredging to add to the money secured in the last legislative session by now-retired State Representative Dan Huberty. New Representative Charles Cunningham will reportedly now carry that banner forward along with State Senator Brandon Creighton.

Legislative News to Follow

March 10th is the last day to file bills in the Texas Legislature this year. Please visit the legislation page on ReduceFlooding.com for updates once bills are filed and start moving forward in Austin.

Thanks to all of our elected and appointed representatives who have pushed so hard on so many fronts for the last 2008 days to tie all the pieces of this complicated flood-mitigation puzzle together.

Posted by Bob Rehak on 2/27/2023

2008 Days since Hurricane Harvey

Engineers Testifying for LCA are Electrical and Chemical, Not Civil

Yesterday’s post cited the testimony of two “licensed professional engineers” in the State of Texas who claimed that Lake Conroe could not refill from rainfall in the Spring or Fall after being lowered one foot to provide an extra margin of safety, which helps prevent flooding homes on both sides of the dam. However, the lake did refill…and then somewithin two days after the Lake Conroe Association (LCA) filed their affidavits in its lawsuit to prevent the seasonal lowering.

Deeper investigation reveals that neither engineer is a civil engineer. One is an electrical engineer and the other a chemical engineer.

From https://pels.texas.gov/roster/pesearch.html

“The Engineer Shall Not…”

Here’s why it is important. Note Paragraphs A and C below.

From Page 84 of PDF at https://pels.texas.gov/downloads/lawrules.pdf

Paragraph A states that engineers shall practice only in their areas of competence.

Paragraph C states, “The engineer shall not express an engineering opinion in deposition before a court … which is contrary to generally accepted scientific and engineering principles without fully disclosing the basis and rationale for such an opinion.”

There was no such disclosure in their affidavits.

In fairness, the engineers also testified as residents and they had more concerns than flooding.

However, both:

  • Cited their professional credentials at the start of their affidavits – without disclosing their areas of expertise.
  • Drew the same conclusion about the inability of the lake to refill through rainfall – without stating the basis of their conclusions.

Mr. Elliott has retired and his license is inactive. Mr. Waitts’ license is still active.

Background

Only two days after LCA filed the engineers’ affidavits, rainfall raised the lake level two feet above normal, and threatened homes and businesses. SJRA had to release water at almost 10,000 CFS to avoid flooding them.

Seasonal Release from Lake Conroe, 529 cfs from one tainter gate open six inches.
SJRA Seasonal Release on 4/15/2020. One tainter gate open six inches released a slow, steady stream of 529 cfs.

Without the seasonal lake lowering policy, someone on either side of the dam would likely have flooded. Dam operators would have been forced to flip a coin to see who. But the seasonal lowering – about which the chemical and electrical engineers complained – helped protect everyone. No one, to my knowledge, flooded on either side of the dam due to river flooding.

Posted by Bob Rehak on 5/23/2021

1363 Days after 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.

LCA Claims “Seasonal Lake Lowering Policy Does Not Allow Lake Conroe to Refill Through Rainfall in Spring, Fall”

Never says never. Especially in a lawsuit. It didn’t take long to disprove that claim! Two days after LCA filed the claim on April 28th, the SJRA had to open its gates to keep Lake Conroe homes and businesses from flooding. And they are still releasing water…three weeks later.

SJRA Dashboard as of 6pm Friday night, 5/21/2021. Normal level is 201. Despite near constant releases this month, the lake’s level has remained above average.

This afternoon, I read the third supplement to the petition by the Lake Conroe Association (LCA) in its lawsuit against the San Jacinto River Authority (SJRA) and nearly busted a gut laughing. After a week where we received more than half the rain for the year so far, I needed the comic relief. And got it.

Two licensed professional engineers – with more than 80 years of experience between them – filed affidavits. They claim that the SJRA’s seasonal lake lowering policy “does not allow Lake Conroe to refill through rainfall in the Spring and Fall.” Their claim is repeated over and over again in affidavits by others.

Lake Conroe Association’s Third Supplement to its Original Petition

SJRA Forced to Go Beyond Seasonal Lowering to Avoid Flooding

Twice this month, the SJRA has had to release water from Lake Conroe above and beyond the seasonal lowering policy to prevent flooding. After the May Day event, they released almost 10,000 cubic feet per second (CFS) for several days to keep the homes and businesses around Lake Conroe from flooding.

The boats are in slips, but the docks are underwater. Near Monty’s Lighthouse and Fajita Jacks on Lake Conroe on 5/1/2021, when the water level exceeded 203 feet halfway through the Spring seasonal lowering.

The rains this week have been more spread out, but the SJRA still had to release almost 3,000 CFS most days to reduce flood risk around Lake Conroe.

Engineers rarely deal in absolutes. They deal in extremes and qualify almost everything they say. But these intrepid professionals stepped over the edge on the far side of reality. Mother Nature always gets the last word.

One of Many Exaggerated Claims

The LCA lawsuit seeks to stop the SJRA’s seasonal lake lowering policy. The “refill” claim is just one of many exaggerated claims that LCA has made.

This lawsuit overflows with self-destructive claims and internal contradictions.

Say That Again!

The latest filing claims that the Lake Conroe Association has the authority to speak for all of its members because LCA feels it proved actual or imminent damages to at least one of its members. In logic, they call that “the fallacy of generalization.” I know at least one influential member of LCA who disagrees vehemently with the lawsuit. So which of those two individuals should we listen to?

LCA also asserts that the Association’s rights are “in every practical sense identical” with “its members.” Its interests, however, may not be.

Some may not find flooding enjoyable.

In its original petition, LCA claimed that its purpose was “over-seeing, directing, initiating, and promulgating programs that directly affect the control, use, and enjoyment of Lake Conroe…” Had it not been for the seasonal lake lowering policy, many homes and businesses upstream or down would likely have flooded after the May Day rains.

In the same sentence about enjoyment, LCA also claims that Lake Conroe is operated exclusively for the benefit of the citizens of Montgomery County, Texas.

Did they really mean to say that Lake Conroe is operated exclusively for MoCo residents when the City of Houston owns two thirds of the water in it?

At one point, the lawsuit claims the sole purpose of Lake Conroe is to supply drinking water. But most of LCA’s complaints refer to lost recreational opportunities.

The second supporting document LCA filed sought relief for irreparable damages but did not specify what those were. Previously LCA members have complained about:

Could Dredging Costs Be The Real Issue?

But LCA’s latest filing reveals what could be the real issue here: dredging. Reportedly, the former president of the LCA had shallow water next to some lakefront property he was trying to sell. But with the water lowered, shallowness made the property less marketable.

Shallow water especially impacts residents at the north end (headwaters) of the lake.

Some LCA affidavits claim that access channels to the lake have been cut off by siltation. This latest filing references dredging in numerous places.

Wildwood Shores claims the estimated cost to dredge area canals exceeds one million dollars. They have hired an engineering company to set up a multi-year dredging plan that would spread out the costs. But they worry that the costs may still not be affordable. Dredging companies have explained the costs of dewatering the dredged materials; hauling them out of the floodplain; and the Army Corps’ permitting process.

Residents from Wildwood Shores, an area without fire hydrants, also claim that the Sam Houston National Forest could burn down if a house fire gets out of control and the local fire department can’t find a way to draw water from the lake.

I wonder if they’ve compared the cost of dredging to putting in a water well and tank from which tanker trucks can refill. I googled “cost of water tanks” and quickly found one that holds 90,000 gallons for $35,000. That’s a lot less than a million dollars for dredging. And the capacity would be enough to fill up at least 30 of the tanker trucks they reference in the lawsuit. The engineer who filed that affidavit didn’t explore that option. Perhaps because he had something else in mind…like boating, for instance.

Let’s Focus on the Real Issues and Work Together

I’m not trying to minimize the:

  • Loss of recreational opportunities
  • Inconvenience of silt
  • Expense of dredging.

We in the Lake Houston Area have been grappling with those same issues…on top of the flooding that silt dams contribute to. They are all real.

But making claims that are false at face value; inventing one doomsday scenario after another; and ignoring reasonable, cost-effective alternatives only undermine your own credibility.

Keeping water high is a temporary solution at best. Eventually, silt will pop up all around Lake Conroe. Especially after heavy rains.

Until you start enforcing regulations that reduce the effects of egregious development (including sedimentation) and form a Flood Control District to help dredge, this problem will dog you.

Realize that we’re all in this together – upstream and down. Let’s focus on ways to mitigate our mutual problems, not fight each other for a temporary advantage.

Posted by Bob Rehak on 5/22/2021

1362 Days after 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.

Floodwaters Converging Downstream on Lake Houston

As of Monday morning, the threat to Lake Conroe had passed, but now floodwaters from the rain soaked northwestern portion of the region are converging on Lake Houston. Here’s a roundup of what’s happening where.

Lake Conroe Going Down

The San Jacinto River Authority reduced its discharge rate to from 9275 cubic feet per second (CFS) to 8120 CFS as the level of Lake Conroe continued to recede, but the West Fork came out of its banks at US 59. The West Fork also began flooding Kingwood’s River Grove Park and the abandoned Noxxe Oil Fields between the river and the Forest Cove Little League Fields.

As of 5:09 pm on 5/3/2021

Lake Conroe Re-Opening With Caution

The SJRA issued a press release at 10:15 am. stating that Lake Conroe will reopen to normal lake traffic at noon Monday, May 3. However, boaters are still urged to use extreme caution due to floating debris and submerged objects that may not be fully visible. With submerged bulkheads, lake area residents should also be cautious of electrical outlets and equipment coming into contact with water.

SJRA is currently releasing water from the Lake Conroe dam to gradually lower the water level back to conservation pool of 201’, but SJRA must strike a balance between upstream recovery and downstream danger. For real-time information on Lake Conroe levels, releases, rainfall totals, or stream flows visit www.sjra.net

SJRA clarified that it intends to return Lake Conroe to 200 until June 1 per its seasonal lake lowering policy as soon as emergency operations restore it to 201. Normally, SJRA would begin recapture on June 1, not May 1. The seasonal release rate is much lower than the current rate.

Floodwaters Converging Toward South and East

Meanwhile, the glut of rainfall that inundated the northwest portions of Houston last week is starting to converging on areas downstream.

As of 10:30 am, the San Jacinto East Fork is also way out of its banks at FM1485 and FM1485 is reportedly closed until Friday. That leaves one way in and out of Colony Ridge – FM2090.

The San Jacinto East Fork at FM2090 peaked overnight and is starting to recede, but is still out of its banks. The East Fork is not influenced by the Lake Conroe Dam, which is on the West Fork.

FM2090 at East Fork near Plum Grove on May 3, 2021 at noon.

FM2090 is still open, but Plum Grove resident Michael Shrader reported a steady line of traffic trying to get out of Colony Ridge up to 11:30 PM Sunday night. This underscores the need to develop alternate evacuation routes for the fast growing subdivision.

Meanwhile, the flood threat is receding at Peach Creek and FM2090.

Caney Creek at FM2090 is getting back within its banks.

And the West Fork, however, is still rising. By 9 a.m. (six hours after the hydrograph below) it was out of its banks at US59.

Flood Warning Remains in Effect for West Fork Until Further Notice

At 2:45 PM CDT Monday, the National Weather Service indicated the West Fork was 49.6 feet.

  • Flood stage is 49.3 feet.
  • Minor flooding is occurring and minor flooding is forecast.
  • Forecast…The river is expected to rise to a crest of 49.7 feet late this afternoon. It will then fall below flood stage late Wednesday morning.
  • Impact…At 49.3 feet, Minor lowland flooding begins in the vicinity of the gage. North side turnaround at US 59 begins to flood. Low points on Thelma Road, Aqua Vista Drive, and Riverview Drive begin to flood.
  • Flood History…This crest compares to a previous crest of 49.7 feet on 11/13/2008.

Here are photos taken along the West Fork this morning.

A young couple surveys rising floodwaters at the turnaround under the US59 bridge. The river bank is about a hundred yards in front of them at the sign in the background. This is the northwestern extent of Lake Houston.
A log jam forms from flood debris under the pedestrian bridge over the West Fork.
Floodwater had crept past the edge of Harris County’s Edgewater Park.
However traffic was still flowing on US59 in both directions.
About a third of the abandoned Noxxe Oil Field by the Forest Cove Little League fields was under water.
The soccer fields at River Grove were partially submerged. Yesterday they were mostly dry.
The boardwalk at River Grove was underwater except for the entrance.
There was no immediate threat to Kings Harbor though the dock was only inches above water.
As floodwaters work their way downstream, Lake Houston continues to rise. As of 5:30PM on 5/3, the lake is now up more than 1.6 feet and many docks are starting to go under.

No widespread flooding is expected in the Lake Houston Area. But people who live in low-lying areas or near the lake should take precautions.

Posted by Bob Rehak on 5/3/2021 based on information from NWS, HCFCD, Jeff Lindner, SJRA, Michael Shrader and personal observation

1343 Days since Hurricane Harvey and 592 since Imelda

Lake Conroe Keeps Rising Despite Increasing Discharges by SJRA

In the last two weeks heavy rains have slammed the areas upstream from Lake Conroe leading to steady rises in the lake level. Had the lake not been lowered earlier, neighborhoods could be flooding now. Streets in several places are already cut off.

As of 7:30 pm Saturday night, 5/1/2021

More Than Three Foot Increase Above Lowered Level

The rain a week ago erased the one-foot seasonal lowering that SJRA started on April 1. Then yesterday’s rains increased the lake more than 2 feet above its normal level of 201 – despite increasing discharges by the SJRA. The lake is now threatening lakeside homes and businesses as you can see from the photos below.

If you’ve watched the dashboard at SJRA.net, the SJRA started discharging 450 cubic feet per second (CFS) before the most recent round of storms. Now the discharge rate has increased to 9275 CFS, which is close to the max rate that the antiquated flood gates on Lake Houston can handle. But even at 9275 CFS, Lake Conroe continued to rise this afternoon.

So did Lake Houston, despite the fact that the Coastal Water Authority has been trying to lower the lake a full foot for several days now.

As of 5:30PM Saturday.

Water Coming from Other Sources, Too

However, in addition to the water from Lake Conroe, Lake Houston is also picking up water from other sources, a number of which are in danger of coming out of their banks.

Status of streams as of 4:15PM on 5/1/2021 according to the Harris County Flood Warning System.

Yellow triangles indicate a stream could come out of its banks. Red exclamation points mean flooding is likely.

This is precisely the scenario that the SJRA designed its lake lowering policy to prevent – an ugly choice between flooding people upstream or downstream.

But the Lake Conroe Association has fought the lowering for the last two years both in a court of law and the court of public opinion. The Association mounted an expensive campaign including billboards, lawsuits, and a legislative offensive against the SJRA. Now, the rapid rise in lake levels may undermine LCA’s support; it certainly undercuts their arguments against seasonal lake lowering.

Water Creeping Closer to Homes and Businesses around Lake Conroe

A Lake Conroe resident who wishes to remain anonymous took the pictures below this afternoon. They show docks underwater, the lake invading shorelines, streets cut off, and homes and businesses being threatened by rising waters.

The docks at Papas on Lake Conroe are underwater.
Water is creeping closer to the Villas at Margaritaville.
This resident said water from the rising lake levels was keeping water from draining into the lake and backing it up into streets.
Docks in front of Monty’s Light House and Fajita Jacks. Those boats are in their slips. The docks are under water.

The marinas on 105 are closed for two reasons. First, the lake is closed to boat traffic because of dangerous conditions. Second, the water is high enough that you can’t get trailers in deep enough, according to one resident. The Walden marina looked like the one above, he said.

One More Round of Thunderstorms Tonight

Expect one more round of storms tonight. National Weather Service radar shows them already sweeping into the Lake Conroe area. They aren’t predicted to dump large amounts of rain, but they will put additional pressure on the homes and businesses around the lake, especially as runoff from previous storms continues to work its way to the lake.

The East Fork in southeast Montgomery County remains under a Flash Flood WARNING, especially areas around Caney and Peach Creeks.

Caney Creek gage at FM2090 as of this afternoon.

And virtually the entire region remains under a flash flood watch through tomorrow morning. A Flash Flood Watch means that conditions may develop that lead to Flash Flooding. Flash Flooding is very dangerous. You should monitor forecasts and be prepared to take action should Flash Flood Warnings be issued.

From National Weather Service on 5/1/21

Posted by Bob Rehak on 5/1/2021 based on information from Lake Conroe residents and the NWS

1341 Days since Hurricane Harvey

Beta Downgraded to Tropical Depression

At 10 a.m. CDT, the National Hurricane Center (NHC) downgraded Tropical Storm Beta to a tropical depression. The NHC also cancelled the tropical storm and storm surge warnings that were in effect. However, flash flood warnings remain in effect for large parts of the seven-county Houston region, especially the southern part. A flash flood watch remains in effect for the entire region.

RadarScope split image. Left half shows track of active storms as of 9:06AM CDT. Right half shows total rainfall accumulation for Beta. Note band of extreme rainfall near Sugar Land and sharp drop-off near Kingwood.

Flash Flood Warnings and Watches

A flash flood warning means that flooding is in progress. A Flash Flood Watch means that conditions may develop that lead to Flash Flooding.

Source: National Weather Service. Updated at 10:29 a.m. 9/22/2020. Reddish area = Flash flood warning. Green = Flash flood watch.

Lake Conroe/Lake Houston Within Banks

Neither Lake Conroe, nor Lake Houston have yet been adversely affected by Beta.

The level of Lake Conroe stands at 199.63 feet. Normal conservation pool equals 201.

According to the Coastal Water Authority, Lake Houston is at:

Lake Level41.41 ft.
Normal Pool42.4 ft.
Source: Coastal Water Authority

USGS shows that even though the lake has received about 1.75 inches of rainfall to date…

…the lake level has been dropping, no doubt due to a preemptive release.

Posted by Bob Rehak at 10:50 on 9/22/2020 based on NHC, NWS, and RadarScope data

1120 Days since Hurricane Harvey and 369 since Imelda

Excessive Rainfall Threat from Beta Spreads Inland

As of mid-day Sunday, all of East Texas now faces some level of excessive rainfall and flash flood risk from Tropical Storm Beta.

The projected path of the storm has shifted inland, so rainfall will reach father north. The latest track now takes the storm on a path right up US59 from Sugar Land to Humble and Kingwood. However, Beta likely be a tropical depression by the time it reaches the north side.

Kingwood is the blue dot next to Spring.

Six to 15 Inches of Rain Now Predicted

According to the local National Weather Service office and the National Hurricane Center, most of the Houston region can expect 6 to 15 inches with the highest totals closer to the coast.

Harris, Montgomery and Liberty Counties (and the whole Houston region) face a high to moderate threat of flooding rains. The first rainbands from Beta have already started to move onshore today, but the heaviest rain will not occur until Monday into Tuesday.

North Houston Under Moderate Flooding Rain Threat

Flash Flood Watch in Effect

The entire region is under a flash flood watch. Coastal areas also face storm surge and tropical storm warnings.

Slow Moving Storm Will Produce Prolonged Rains

Beta is meandering slowly at about 3 mph northwest toward the coastline west of Houston and will then curl back over Houston. It should move inland sometime Monday or Monday night and turn from a storm into a depression by the time it reaches Houston.

However, Beta could dump rain on us from later today all the way through Wednesday.

40-50% Chance of Tropical Storm Force Winds Reaching North Houston

The North Houston Area has a 40-50% chance of seeing tropical storm force winds from Beta.

If the high winds reach this far inland, they would likely arrive Monday evening. Winds extend outward from the center for 195 miles as of Sunday morning.

Feeder Bands Extend Outward 190 Miles

In fact, at 11 a.m. Sunday morning, the first feeder band was approaching the eastern side of Houston, as you can see in the radar image below.

This image shows how the wind and rain from Beta could remain with us for days as the storm’s center wanders around the Gulf.

These feeder bands reach out 190 miles. That is roughly the distance from Houston to San Antonio. So Beta will produce long-duration rainfall from the middle Texas coast to southern Louisiana. 

Flash, Urban, and River Flooding Likely 

The National Weather Service warns that coastal flooding will remain a threat through midweek with the worst of the storm surge anticipated on Monday and Tuesday. 

Elsewhere impacts from the excessive rain include:

  • Rainfall flooding may prompt evacuations and rescues.
  • Rivers and tributaries may rapidly overflow their banks.
  • Small streams, creeks, canals, and ditches may become dangerous rivers.
  • Flood control systems and barriers may become stressed. 
  • Flood waters may cover escape routes. 
  • Streets and parking lots may become rivers of moving water with underpasses submerged.
  • Driving conditions may become dangerous. 
  • Many roads and bridges may close with some weakened or washed out.

Lake-Level Situation

According to the SJRA, Beta has the potential to dump up to 8 inches of rain in Montgomery County

SJRA is operating under standard protocols for a severe weather event and will be onsite at Lake Conroe throughout the duration of Tropical Storm Beta.  

Lake Conroe remains 18 inches low, and based on the current forecast, no reservoir releases are expected. 

SJRA

Real-time information on lake level can be found on the SJRA homepage at the “Lake Operations and Rainfall Dashboard” link.

At of this writing, Lake Houston is down a foot compared to its normal pool level (41.38 vs 42.4). You can monitor Lake Houston levels via the Coastal Water Authority website.

Monitor Downstream River Levels

You can monitor stream and river levels in near-real time at Harris County Flood Warning System. Make sure you check out the inundation mapping feature.

Posted by Bob Rehak on 9/20/2020 based on information from the National Weather Service and National Hurricane Center

1118 Days after Hurricane Harvey

SJRA Considering Input on Lake Conroe Reservoir Forecasting Tool Thursday, 6PM

San Jacinto River Authority (SJRA) will hold public meeting on Thursday, September 10, 2020, at 6:00 p.m., via webinar and telephone conference, to discuss its ongoing Lake Conroe Reservoir Forecasting Tool Project.

Accurately determining inflow during a flood theoretically lets dam operators determine how much water to release and when. That, in turn, helps protect properties both upstream and downstream to the extent possible.

During Harvey, many felt that the SJRA released too much water too quickly – 79,000 cubic feet per second at one point. That, they say, flooded homes downstream unnecessarily when capacity still existed in the reservoir. Lawsuits are still working their way through the courts.

Many also complained about the lack of warning for the massive release which inundated homes as people slept.

Residents trying to escape as Harvey's floodwaters rose
Senior residents of Kingwood Village Estates trying to escape as Harvey’s floodwaters rose.

Additional Information

The Lake Conroe Reservoir Forecasting Tool Project addresses flood protection in the San Jacinto River Watershed.

One goal: to anticipate peak water level in Lake Conroe during rainfall events based on:

  • Weather forecasts
  • Observed rainfall
  • Lake levels
  • Other data. 

A second goal: to predict peak release rates of stormwater from Lake Conroe.

The SJRA says this will help improve communication with Offices of Emergency Management and the general public during rainfall events. 

SJRA expects completion of the project by early spring 2021. The Texas Water Development Board (TWDB) and SJRA have funded the project.

Ask Questions, Express Views

You can view and participate in the meeting remotely via the webinar link below to express your views of the Project.

Questions or requests for additional information about the SJRA Reservoir Forecasting Tool may be directed to Mr. Matt Barrett, P.E., Division Engineer, SJRA, 1577 Dam Site Road, Conroe, Montgomery County, Texas 77304, Tel. (936) 588-3111. 

SJRA requests those who intend to express their views to contact Mr. Barrett either in writing or by telephone in advance of the meeting. 

To Participate Via Webinar and/or Comment

Only those participating via Webinar using the GoToWebinar App will be able to provide comments during the meeting.

Webinar Link: https://attendee.gotowebinar.com/register/5029250157384078351
After registering, you will receive a confirmation email containing information about joining the webinar.

Please use Webinar ID: 372-655-099

To Participate Via Phone and Listen

If you choose to participate via conference call using the number below, you will NOT have the opportunity to provide comments during the designated portion of the meeting. The conference call phone number is provided for LISTENING PURPOSES ONLY.  

Telephone conference call phone number: (562) 247-8321 and the audio access code is 150-445-802

Editorial Comment

I, for one, hope they use their new Reservoir Forecasting Tool to release floodwater at safe rates, although that was not explicitly stated in the SJRA press release on the meeting. Releasing at safer rates may mean releasing water earlier or holding it longer to flatten peaks. In my opinion, SJRA should hold floodwater as high as they safely can…as long as they safely can. I hope this new tool helps SJRA do that.

I’d rather see floodwater in Lake Conroe than in Kingwood’s Town Center.

Kingwood Town Center Apartments after Lake Conroe Release. Yes, that’s the top of an SUV that failed to evacuate in time.

Posted by Bob Rehak on September 9th, 2020

1107 Days since Hurricane Harvey

Lake Conroe Lowered to Target Level for August; LCA May Be Gearing Up For Another Fight

Since August 1, the level of Lake Conroe has hovered around 200 feet. As of this writing, it stands at 199.95 feet, virtually at the target level of the seasonal lowering for the month. That’s three hundredths of a foot above its seasonal average for the last 46 years and five hundredths of a foot below the target level. Yet the Lake Conroe Association appears to be gearing up for another fight to end the program.

Lake Conroe level as of 8/10/20 at 4:30 pm. Source: SJRA.net.

Seasonal Averages

Lake Conroe seasonal levels by month. Source: SJRA

History of Strategy

The SJRA started seasonally lowering the level of Lake Conroe in 2018 after Governor Abbott directed the SJRA to develop strategies to help protect downstream communities from flooding. Due to a slight drought in late 2019, the lake level did not recover quickly. The Lake Conroe Association (LCA) then organized protests as the SJRA reconsidered the strategy for this year.

Seasonal Release from Lake Conroe, 529 cfs from one tainter gate open six inches.
SJRA Seasonal Release on 4/15/2020. One tainter gate open six inches releases a slow, steady stream of 529 cfs. No one flooded downstream last Spring during the release.

Ultimately, the strategy adopted by the SJRA represented a compromise. During September/October, the lake will remain a half foot higher than in previous years (200 vs 199.5).

Here’s how the current and previous targets compare to what Mother Nature provides through rainfall and evaporation.

In August, little manual lowering should be needed. In September and October, much less lowering will be needed compared to the previous plan adopted in 2018.

SJRA’s Plan for Fall Lowering

SJRA’s current official policy reads as follows.

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.”

Compared to the seasonal average, the plan really only amounts to lowering the lake 2 to 3 inches in September and October.

Lake Conroe Association Gearing Up for Another Fight?

Regardless, the Lake Conroe Association (LCA) is reportedly gearing up for another fight.

Community Impact newspaper reported in its August 2020 issue that LCA filed a complaint with the TCEQ on June 30 to end the seasonal lowering of Lake Conroe.

On August 7, they sent an email out to requesting Lake Conroe residents to donate money to the Lake Conroe Association so that it could “replenish the reserve funds spent to oppose the San Jacinto River Authority (SJRA) lake lowering program.”

In the next paragraph, they ask Lake Conroe residents to provide comments to the Sunset Commission reviewing the SJRA.

Screen Capture of LCA Communication on 9/7/2020. Links not active.

Neither of those two actions is a threat. But juxtaposing them like that is certainly walking up to the firing line … with the chamber loaded.

There sure is a lot of energy expended over two or three inches of water.

Lake Conroe people claimed last winter, when the SJRA was reconsidering the policy, that the lowering would not help Lake Houston Area residents. Lake Houston Area residents, still feeling the pain of Harvey, want all the help they can get.

Enough said.

Posted by Bob Rehak on 8/10/2020

1077 Days after Hurricane Harvey