Tag Archive for: seasonal lowering

Digest: Updates on Six Lake Houston Area Flood-Related Stories

Below is a quick digest of six flood-related stories affecting the Lake Houston Area.

Dredging is a Slow Go

Mechanical dredgers are slowly working their way through the channel south of Royal Shores. It connects the East and West Forks of the San Jacinto. Without dredging, the dredging equipment itself would not be able to make it through the channel.

However, the pace of the dredging is painfully slow. You can see the progress by comparing the two pictures below. I took them 22 days apart.

Taken on July 11, 2021
Taken on August 2, 2021.
Google Earth shows they went a little more than 600 feet in a little more than three weeks.

At about 200 feet per week with about 2,000 more feet to go, they should reach the East Fork in about another ten weeks.

Several boaters have commented on how the dredges can wait hours for a pontoon to ferry dirt back to the placement site. Their net takeaway: very inefficient. During a July 8 meeting at the Kingwood Community Center, Stephen Costello called this method of dredging “unsustainable.” He’s sooooo right. We will run out of luck long before we run out of places to dredge.

Mechanical dredging (shown in the photos above) is far slower and less efficient than hydraulic. Great Lakes hydraulic dredges removed 500,000 cubic yards of sediment from the mouth bar area in just two months – July and August of 2019. DRC’s mechanical dredges removed another 600,000+ cubic yards in the 19 months between January 2020 and July 2021.

Interestingly, Google Earth shows that when the dredgers reach the East Fork, they will be closer to the Triple PG Sand Mine in Porter than the current placement area south of River Grove Park. The Triple PG mine will also be less than half the distance of a mine that the Army Corps previously pumped spoils to from the mouth bar– the Eagle Sorters Mine on the West Fork.

Hmmmm. Triple PG. A placement area for East Fork spoils? A return to hydraulic dredging? Interesting thoughts.

Seasonal Lowering of Lake Conroe

Seasonal lowering of Lake Conroe has started as planned. SJRA is releasing 75 cubic feet per second, according to their dashboard.

Seasonal release is shown as a City of Houston (COH) Diversion.

When the lowering started on August 2, a day late, the lake was at 200.87. So releasing 75 CFS has brought the lake down .19 feet, a little more than 2 inches. Barring large rainfalls, this rate should reach the objective of 200 feet by September 1.

The Lake Conroe Association is still fighting the lowering in Montgomery County District Court. Judge Mike Mays set a hearing date for Tuesday, August 24, 2021 at 2PM.

Tropics Heating Up

Five Day Tropical Weather Outlook from National Hurricane Center

The National Hurricane Center shows two areas of concern in the Atlantic as of 2PM, Friday August 6th.

A few hundred miles south of the Cabo Verde Islands, a tropical wave (orange area) and a broad area of low pressure could turn into a tropical depression by late this weekend or early next week. Formation chance through 5 days…medium…60 percent.

Another tropical wave approaching the Lesser Antilles is a lower threat. NHC predicts development, if any, of this system will be slow and occur early next week. Formation chance through 5 days…low…20 percent.

NOAA Issues Mid-Season Hurricane Outlook

Another forecast released two days ago by NOAA says that atmospheric conditions are still conducive for an above-average hurricane season. See their predictions in the right hand column below. These numbers include the five named storms so far this season.

Attorney General Lawsuit Against Triple PG Mine Still Active

Craig Pritzlaff of the TCEQ assures me that despite visible lack of progress in the Attorney General’s lawsuit against the Triple PG mine for illegal discharges, the AG has not dropped the case. “Indeed, very few, if any, cases referred to the AG for civil prosecution are ever dropped,” he says. “Litigation, particularly environmental litigation, is a complicated and lengthy process. That process was further complicated by the COVID-19 pandemic, which halted court dockets across the State throughout 2020 and into 2021.”

Condos 250 Feet from 250,000 CFS

A Chinese developer is building yet more condos even closer to the West Fork in the Kings Harbor neighborhood.

See new construction bottom center. Lai finished the units at the right earlier this year.
The nearest unit above will be about 250 feet from the San Jacinto West Fork.

During Harvey, more than 250,000 cubic feet per second came through this area. It flooded homes and businesses more than 10,000 feet from the river.

The developer is also hoping to sell/develop that grassy area in the bottom center of the photo for $1.45 million.

I guess money has a short memory.

That concludes this month’s digest.

Posted by Bob Rehak on 8/6/2021

1438 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.

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.

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

Lake Conroe Association Applies for Temporary Restraining Order To Prohibit Seasonal Lowering of Lake Conroe

They’re baaaa-aaaack. Yesterday, less than a day before the SJRA spring seasonal lowering program was set to kick in, the Lake Conroe Association (LCA) applied for a temporary restraining order to prohibit it. The LCA also seeks a permanent ban on the entire program. For the complete text of their 30-page lawsuit, click here. For a summary, see below.

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.

History of Lake Lowering Policy

After disastrous flooding during Hurricane Harvey in 2017, Governor Abbott instructed the SJRA to get into the flood mitigation business and identify strategies to reduce the risk of downstream flooding. The simplest, fastest, most effective strategy that required no grants, funding, design or construction was to lower Lake Conroe during the peaks of spring and fall flood seasons. This created an extra buffer against downstream flooding by creating extra capacity in the upstream lake.

The seasonal-lowering policy started in 2018 and continued in 2019. By late 2019 when the SJRA was getting ready to review the policy for another year, the Lake Conroe Association mobilized opposition in a major-league way. People came to SJRA Board meetings in busloads. There were so many that they couldn’t all get in the SJRA boardroom to be heard. So the next meeting was held in the Conroe Convention Center. Close to a thousand “Stop the Drop” protesters showed up. They argued that lowering the lake a foot was destroying businesses around the lake, undermining property values, destroying the local school system, and threatening the entire tax base of Montgomery County.

They also argued that Lake Conroe was never intended to be a flood control reservoir, and that the policy wasted water, produced no benefit, and had minimal effect. The current lawsuit makes many of these same hyperbolic arguments.

Allegations in Lawsuit

Below, see the major allegations in the seasonal-lowering lawsuit (italics) and my responses (normal text).

The SJRA and City of Houston are unlawfully discharging billions of gallons of water from Lake Conroe which causes it to remain below full capacity. However, a quick check tonight showed that the lake was actually above its normal capacity.

The Lake Conroe Dam is being operated contrary to state law. The operation was initiated at the request of the governor and approved by the TCEQ as an emergency measure while permanent downstream flood mitigation efforts could be put in place.

Lake Conroe Dam operation is contrary to the interests of the parties “for whom the lake is maintained, regulated and conserved.” The City of Houston paid for the construction of the dam and owns two thirds of the water in the lake. The operation benefits Houston residents and was requested by the Mayor of Houston. So I ask, “For whom is the lake maintained, regulated and conserved?”

The State is entitled to regulate water to protect its citizens’ health and safety. Isn’t that what the lake-lowering policy ensures?

Lake Conroe is not a flood control reservoir. Right! We’re trying to do the best with what we have.

The policy doesn’t conserve water. Right again! But it does conserve downstream property and lives. Somehow those got lost in the LCA arguments. For a list of Lake Houston Area damages during Harvey, click here.

Flood control is not permitted for Lake Conroe. But the TCEQ did permit it. And the TCEQ rejected an LCA appeal last year.

There’s no evidence that the policy works. Tell that to the people who didn’t flood in this storm.

The policy is not really temporary. Why was the policy enacted for three years then? It’s intended to allow safe completion of additional gates on the Lake Houston Dam.

The seasonal releases happen far in advance of a storm. Lake Conroe’s gates can release water 15 times faster. If a major storm approaches and a large release becomes necessary, it could overwhelm the gates on Lake Houston. The slow seasonal release safely reduces that risk.

Harris County Flood Control’s Harvey Report found the benefits of lowering Lake Conroe to be “negligible.” That’s a lie. The word negligible never appears in the report. And the lawsuit distorts the figures. It claims the Lake Conroe release accounted for at most 16% of the water going over the Lake Houston Dam. But it was one third of all the water coming down the West Fork where the vast majority of the damage occurred. The lawsuit allegation includes East Fork water to exaggerate its claim. The Lake Conroe Dam has no effect on East Fork flow. Also consider this. All by itself the Lake Conroe release during Harvey would have ranked as the ninth largest flood in West Fork history. Hardly negligible!

Petitioners continue to be affected in their rights to their use and enjoyment of Lake Conroe. Now we’re getting to the heart of the matter. But these photos show little impact on recreation even when the lake was lowered two feet.

Water released as part of a seasonal lowering will never be available for use. Rain replenishes the lake at no cost.

As of 8pm on 3/31/2021, Lake Conroe was at its normal “target level.” The SJRA lake lowering policy calls for lowering it one foot during April and May.

Without the TRO, Lake Conroe residents will have no adequate remedy to protect the “public’s interest.” Which public? The owners of the water? Or residents of Lake Conroe?

Lake Conroe Residents Don’t All Agree with LCA

Not all Lake Conroe residents agree with this petition. Though the petition gives no hint of that. Many who flooded during Harvey have previously testified that they want the lake lowered – permanently!

Exaggeration Upon Exaggeration

This lawsuit exaggerates. And that’s its biggest flaw. It sounds like the kid who tells the teacher “My dog ate my homework, right before a bus ran him over, and a 747 crashed into the bus. I tried to retrieve my homework, but the fire department washed it down the sewer. And now it’s floating in Lake Conroe where water skiers are tripping on it. That’s going to destroy home values on Lake Conroe and undermine the tax base of the school district. So you see, Teach, we have much bigger things to worry about. Like your salary and job security.”

For more about the seasonal lake lowering policy, click on this page.

Hearing Scheduled

It’s not clear yet how this lawsuit will affect the spring lowering of Lake Conroe scheduled to start Thursday. The lawsuit is scheduled for a hearing on 4/19/2021 in Montgomery County.

Posted by Bob Rehak on 4/1/2021

1311 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.

SJRA Starts Seasonal Release to Lower Lake Conroe

After the Easter weekend, the San Jacinto River Authority (SJRA) started its seasonal-release plan. The river authority is currently releasing at a rate of 529 cubic feet per second (CFS) from Lake Conroe. At that rate, the lake should reach its target level of 200 feet above sea level by the end of April, according to Jace Houston, general manager of the SJRA.

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. Image courtesy of SJRA.

The slow rate of release avoids flooding downstream property and the lower lake level provides additional capacity in the lake. That additional capacity provides a buffer against flooding for downstream residents.

About Seasonal Lake Lowering Policy

Houston said the River Authority will hold the lake at 200 feet through the end of May, then allow it to reach its normal level for most of the summer.

Lake Conroe actually reached 200.75 feet before SJRA began its seasonal lowering this week. A reduction of .14 feet equates to about one and two-thirds inches of lowering so far.

At 200.75 feet, Lake Conroe was actually above its highest average monthly level for the year, which is 200.44 feet in May. The normal level for April is 200.32 feet.

Lake Conroe seasonal levels by month. From SJRA board presentation by Chuck Gilman in January.

Earlier this year, a bitter fight broke out between upstream and downstream property owners over the seasonal lake lowering policy. The SJRA board decided to extend the lake lowering plan, but modify it. In the fall, they will let the City of Houston, which owns two-thirds of the water in the lake, decide whether to take the lake down below 199.5 feet.

The extra lowering in the fall helps protect against hurricanes and tropical storms, such as Harvey and Imelda. The SJRA begins slowly lowering the lake in August for the peak of hurricane season in September and then letting it resume its normal level again in October. For the exact details of the policy adopted by the board in its February meeting, click here.

Lake Houston Level Declining

Despite the start of the seasonal release and last week’s rains, the level of Lake Houston has declined this week. And rivers are far from flooding.

Normal level for Lake Houston is 42.5 feet, but City is still lowering lake for spillway maintenance.

Uncertain Weather for This Weekend

Jeff Lindner, Harris County meteorologist, predicts that storms this weekend could bring several inches of rain. “With the Gulf of Mexico water temperatures running several degrees above average for this time of year, winds blowing off the Gulf will need little time to supply a rich moisture-laden air mass.” 

The NWS predicts a 30-40% chance of showers and thunderstorms for this weekend as a front passes. However, Lindner notes, models diverge widely in their predictions. The Global Forecast System (GFS model) predicts that most rain will happen over the Gulf with little impact to land.

However, the European Medium Range Forecast Model (ECMWF) predicts a very wet weekend with several rounds of storms and several inches of rainfall for much of southeast Texas.

Which Model is Better?

ECMWF is considered one of the premiere global forecasting models for the mid-latitudes. Statistically, it has been more accurate than the GFS model.

NOAA has tripled spending on supercomputing capacity to make GFS the best model in the world again.

Posted by Bob Rehak on 4/15/2020

960 Days after Hurricane Harvey

Lake Conroe Level Now Exceeds Average for April a Week Early

The rain earlier this week continues to filter into Lake
Conroe and raise the lake level. As of today at 3 p.m. today, the level reached 200.35 msl (mean feet above sea level).

Lake Conroe level as of 3pm on 3/24/2020

That means the lake level now exceeds the average for April – and there’s still a week left in March. With additional rain or inflow, the lake could soon reach its highest point in an average year.

Monthly variation in average levels of Lake Conroe dating back to 1973 when the dam was built.

The highest monthly average happens in May when the lake reaches 200.44 feet. That means the lake is now 0.09 feet (1.08 inches) from its average annual peak in May.

That also means that the SJRA will begin releasing water on April 1 as part of its seasonal lowering plan to reduce flood risk to downstream communities.

Posted by Bob Rehak on 3/24/2020

938 Days since Hurricane Harvey

One Less Thing to Worry About in Latest Storm: How Seasonal Lowering of Lake Conroe Helped

Storms during the last two days were traumatic for virtually everyone in the Kingwood area. Tragically, one person lost her life when her car hit a downed tree.

  • Others lost vehicles, trees, and sleep.
  • Torrential rains for a brief period – at the rate of 4-5 inches in an hour – flooded streets and vehicles.
  • They also brought water near or into homes.
  • Parents picking children up from school waited in rising waters as their students sheltered in place.
  • A small tornado may have briefly touched down near Town Center.
  • Kingwood Drive was shut down for hours during the Friday afternoon rush hour.
  • People traumatized by Harvey were re-traumatized.
  • People without power waited and wondered for hours about what was going on around them.

Lake Conroe: One Less Worry This Time

Despite all that, we did NOT have to worry about one thing: Lake Conroe opening its flood gates again during this storm. The seasonal lowering policy established last year worked.

The SJRA board voted to lower the lake’s level one foot to 200 mean feet above sea level (MSL) from April 1 to May 31.

That action may have saved the Lake Houston area from additional flooding in the last round of storms.

Releasing Water Continuously At Low Rate Created Extra Capacity

Lake Conroe had released water continuously since April 1 at a slow, controlled rate of 350 to 550 cubic feet per second. However, because of spring rains, Lake Conroe had only dropped about a half foot from 201 to 200.66 feet MSL. Had the releases not happened, the lake would have been an estimated 1-1.5 feet higher, according to Mark Micheletti, an SJRA board member from Kingwood. That means the lake level would have been approaching 202 feet, the level at which the SJRA automatically begins releasing water, when the storm hit. That would have forced the SJRA to release water at a higher rate that could have overloaded the downstream watershed.

Buffer Against Downstream Flooding Worked

In other words, the policy worked. The seasonal lowering provided a buffer against downstream flooding. NOAA shows a double crest on the San Jacinto West Fork at US59 during the last two days that coincided with two waves of storms. At peak flow, the river came within about two feet of going out of its banks.

An additional foot of water released from Lake Conroe would have added two feet to Lake Houston and created flooding.

About a mile downstream at River Grove Park, the water was up, but still within its banks.

Despite torrential rains last night and early this morning, the West Fork remained in its banks. The river was up, but no homes flooded from the river.

Success: No Rivers or Streams Out of Banks

At this hour, neither NOAA, the SJRA, nor Harris County Flood Control, predicts any flooding from yesterday’s storms. In fact, all streams and bayous seem to be receding at this time. That’s one less thing to worry about as we clean up from the latest storm. The SJRA’s seasonal lowering DID help.

Remember, Lake Conroe is almost twice as big as Lake Houston (33 sq. mi. vs 18.5 sq. mi.). So one foot released there translates into almost two feet here. And two feet would likely have forced the San Jacinto out of its banks for the fifth time in a year.

Kudos to the SJRA board, the City of Houston, and the TCEQ for enabling this policy. That, in conjunction with the City’s pre-release policy for Lake Houston, have made a difference.

Posted by Bob Rehak on 5/5/2019

614 Days since Hurricane Harvey

Lake Conroe Seasonal Lowering Reaches Target Level at Peak of Hurricane Season

Earlier this year, the San Jacinto River Authority (SJRA) voted to lower the level of Lake Conroe during the peak of hurricane season. The purpose: to provide an additional buffer against flooding for downstream residents until the river could be dredged. The SJRA has now reached its target of 199 mean feet above seal level (MSL).

Temporary Lowering Accommodates Dredging

The SJRA stated, “This was the target elevation established by the San Jacinto River Authority and the City of Houston to create a temporary flood mitigation benefit while dredging activities take place in the lower part of the San Jacinto River.”

The lowering happened gradually during August. To avoid downstream flooding, the  SJRA released water at the rate of 200-300 cubic feet per second. That amounted to  about an inch per day. The exact amount varied due to occasional rain and evaporation.

Lake Conroe Will Return to Normal Level After September

“Now that the target elevation has been reached,” said the SJRA, “Reservoir operators have shut off the release of water from the dam and will operate with the goal of maintaining the current elevation through the end of September. After September, any rainfall flowing into the reservoir will be held, and the reservoir will be allowed to return to the normal elevation of 201 ft-msl.”

Update on Dredging Schedule

As tropical activity heats up, this is good news. The U.S. Army Corps of Engineers is nearing completion of the assembly of the first of two dredges and miles of dredge pipe. The contractor for the Corps’ Emergency West Fork Dredging Project, Great Lakes, is expected to begin dredging on September 6. Dredging will extend from River Grove Park on the west to Chimichurri’s on the east. It’s not clear yet, which end the contractor will begin on. Great Lakes expects to complete the project, weather permitting, by April of next year.

Posted September 1, 2018 by Bob Rehak

368 Days since Hurricane Harvey