Tag Archive for: Active Storm Management

“Seasonal” Lake Lowering Out. “Active Storm Management” In.

The San Jacinto River Authority and City of Houston have abandoned their automatic “seasonal” lake lowering policy. The seasonal program lowered Lake Conroe automatically to fixed levels during the rainiest parts of the year (April/May and August/September, i.e., the peak of hurricane season).

They have replaced seasonal lowering with a new program called “active storm management” that gives the City and Lake Conroe dam operators more flexibility to respond to actual weather conditions.

Basically, they can keep water levels up when no storms are expected. But they can lower the lake in advance of major rain…any time of the year…by amounts that will keep the lake level as stable as possible and downstream residents as safe as possible.

It’s a compromise that can be summed up in the words “as needed vs. automatic.”

Below, you can see the exact wording of the new protocols. Below that, you can see my simplified summary/interpretation. I also provide a link to the actual contract between the City and SJRA.

Active Storm Management Protocols for Lake Conroe and Lake Houston – 2024

  • Beginning April 1 through June 1, the City of Houston may request diversions to lower Lake Conroe from normal pool of 201’ msl to create up to six inches of storage capacity for forecasted storm event inflows (to 200.5’ msl). The decision of when, how, and whether to initiate diversions will be guided by climate conditions, weather patterns, and available water supply.
  • Resume normal recapturing after each storm event that triggered any diversion between April 1 and June 1.
  • In the event a major rainfall is forecasted to impact our region, active storm management protocols of the City of Houston could initiate a diversion to create up to an additional six inches of storage capacity for storm inflows (to 200.0’ msl). It is acknowledged that under extraordinary weather circumstances, additional diversions to create capacity below 200.0’ msl could occur.
  • Beginning August 1 through October 1, the City of Houston may request diversions to lower Lake Conroe if actual lake levels are at normal pool of 201 msl to create up to six inches of storage capacity for storm inflows (to 200.5’ msl). After Labor Day, storage capacity may be increased an additional six inches (to 200.0’ msl). Diversion volumes requested to reach intended levels will be dependent on the actual lake levels. The decision of when, how, and whether to initiate diversions will be guided by climate conditions, weather patterns, and available water supply.
  • Resume normal recapturing after each storm event that triggered any diversion between August 1 and October 1.
  • If a named storm is predicted to impact our region, active storm management protocols of the City of Houston could initiate a diversion to create up to an additional six inches of storage capacity for storm inflows (to 199.5’ msl). It is acknowledged that under extraordinary weather circumstances, additional diversions to create capacity below 199.5’ msl could occur.
Protocol – Lake Houston
  • Year Round
    • City of Houston will initiate releases to lower Lake Houston prior to major rainfall events.
    • Conservation Pool Elevation is 42.4’ msl.
    • Lake Houston level reduced to 41.4’ msl if a 24-hour rainfall forecast of 3 inches or more is expected. within the Lake Houston watershed.
    • Under extraordinary weather circumstances, Lake Houston level may be reduced below 41.4’.
  • The Protocols above will extend to the end of 2024 but will be reviewed by the stakeholders in October/November of 2024. During the review, the stakeholders will discuss strategies that extend beyond 2024.
Advocacy and Education
  • All stakeholders will work to support flood mitigation projects and efforts across the upper watershed, including improvement of land use regulations to reduce runoff from new development in counties that contribute flow to Lake Houston.
  • Because public education regarding completed and ongoing downstream mitigation efforts is critical to generating upstream support for continued active storm management at Lake Conroe, all stakeholders agree to educate their constituents regarding: active storm management protocols being implemented at Lake Houston, completed and ongoing sediment removal projects in the San Jacinto River basin and Lake Houston, and continued progress on the Lake Houston spillway modifications.
  • Because of its impact on effective active storm management, all stakeholders will support City of Houston and SJRA efforts to amend the Certificate of Adjudication for Lake Conroe to increase the maximum diversion rate.
  • All stakeholders agree to support efforts to limit further construction of habitable structures around Lake Conroe below elevation 207’ msl.
Important Notes
  • All water released from Lake Conroe as part of active storm management is being accounted for from the City of Houston’s 2/3 share and reported to TCEQ by the City of Houston. Therefore, all final decisions on diversions are ultimately the City’s and must be communicated to the SJRA in writing. This includes defining active storm management protocols.
  • All flood mitigation protocols could be limited due to drought conditions.

Rehak’s Summary

Note the words “MAY REQUEST” in the first sentences under Spring and Fall. Lowering is now on an “as needed” basis, not automatic.

Note also the words “RESUME NORMAL RECAPTURING” in the second bullet points under Spring and Fall. Operators will attempt to return the lake to its normal level after the storm threat has passed. The lake will not automatically be kept lower for the rest of the season.

All stakeholders have agreed to review the policy at the end of this year and modify it as necessary.

All stakeholders have also agreed to support mitigation projects including:

  • Land use regulations that reduce runoff
  • Education of residents re:
    • Active storm management protocols at Lake Houston
    • Construction progress of more Lake Houston gates
    • Sediment removal projects
  • An increase in the maximum pre-release rate for Lake Conroe
  • Limiting future construction around Lake Conroe to a safe level (207 feet above sea level).

The City of Houston must initiate lake lowering IN WRITING.

Water released from Lake Conroe at the City’s request will be reported to the TCEQ.

The City makes all decisions on releases.

Its decisions are final.

The City may redefine “active storm management” protocols, but should consider drought conditions when making decisions.

Decisions to Lower Lake Outside of Spring/Fall Dates

A release during Tropical Storm Alberto in June this year triggered a protest from the Lake Conroe Association because it fell outside the dates indicated above (April/May and August/September).

However, during the April SJRA Board meeting at which Active Storm Management was approved unanimously, the official minutes note that all parties agreed that the City could order the release of water from Lake Conroe at any time – regardless of the season.

For the historical record, here is the actual contract between the City and SJRA re: the operation of Lake Conroe.

For ease of future reference, you can also find the details above on this site’s Lake Lowering page.

Posted by Bob Rehak on 6/25/24

2492 Days since Hurricane Harvey

Lake Conroe Association Complains About Lowering Lake Conroe … Again

Updated 6/25/24 – After the near miss with Tropical Storm Alberto, Lake Conroe Association (LCA) President Kevin Lacey penned an angry, demanding letter to the City of Houston (CoH) about lowering the lake 5 inches.

Complaints In Lacey Letter

Among other things, the letter complains that:

  • Lowering the lake after June 1 is a “breach” of the “Active Storm Management Agreement”
  • The amount of rainfall in the original prediction did not justify the amount of “excessive” lowering
  • CoH did not stop lowering Lake Conroe when the storm veered to the southwest
  • CoH wasted its water, instead of using it “beneficially”
  • The lake likely won’t be able to recover its normal water levels during summer

Use of the word “breach” by Mr. Lacey seems to imply that his association has legal standing to dispute the actions of the SJRA and CoH. He demands that they account to him for their actions during the storm at a special meeting with LCA.

The Lake Conroe Association has a long history of protesting lake lowering. LCA sounds like a homeowner’s association, but it is not. LCA was originally founded as a nonprofit 50 years ago to combat the growth of Hydrilla (a fast-growing invasive plant species) around the lake.

Since then, LCA claims it has raised a million dollars ($20,000 per year) through donations. Currently it claims it is also fighting for “safe water levels.”

Motive Behind the Fight?

Some believe that insufficiently dredged areas around Lake Conroe motivated this fight. Regular HOAs cannot afford dredging and homeowners have difficulty operating their boats when lake levels are down.

Mr. Lacey seems oblivious to fact that many around the lake see preemptive lowering as a positive thing that helps reduce their flood risk. Anecdotally, I have heard that many homes flooded around Lake Conroe during May although I don’t have an exact count.

May Storm Dramatizes Problem of Forecast Uncertainty

After 7 inches of rain fell north of Lake Conroe in late April, SJRA began releasing water for days. They had the release rate down to 8,000 cubic feet per second (CFS) and were actually decreasing the release rate, when another 11 inches fell in the same location.

Lake Conroe flood gates
Gates at Lake Conroe can release water 15X faster than Lake Houston’s gates. This makes coordinating pre-releases difficult.

Within hours, SJRA escalated the release rate to 72,000 CFS, flooding hundreds of homes downstream, nearly flooding thousands more, breaking sand mine dikes, and sweeping sediment downstream – just as the CoH was about to begin a $34 million dredging program.

Seventy-two thousand CFS was SJRA’s second highest release rate in its history. Only Hurricane Harvey’s 79,000 CFS exceeded that.

Decreasing the release rate just hours before increasing it 9X underscores the difficulty of precisely predicting how much rain will fall where.

But Mr. Lacey didn’t acknowledge that difficulty anywhere in his letter. Nor did he reference the May storm. Or homes around Lake Conroe that flooded. Or that the City of Houston has the right to call for SJRA water year round.

He especially forgot to mention that when Alberto was pushing southwest, the National Hurricane Center predicted that another potential tropical storm could move north toward Houston. That explains the likely reason Houston continued calling for 660 CFS even after Alberto headed for Mexico and the Valley.

Ultimately, the second storm followed Alberto into Mexico yesterday. But had it moved north, there wouldn’t have been time to achieve meaningful lake-level reduction without flooding homes downstream and staying within the bounds of Lake Conroe’s permit from the TCEQ.

Correcting Other Allegations

To correct some other issues in the Lake Conroe Association letter:

  • While releasing 660 CFS per second before and during Alberto, SJRA did not exceed its TCEQ Permit which specifies 700 CFS maximum. If Mr. Lacey supported increasing that, perhaps next time, SJRA could release water closer to storms when the certainty level of forecasts is higher.
  • Breach implies some kind of a contract exists between LCA and CoH. It doesn’t. Rather, SJRA has a series of operational guidelines in place with CoH.
  • CoH owns two-thirds of the water in Lake Conroe. The “agreement” referenced by Lacey isn’t even labeled as an agreement. It’s a series of operating protocols. They let CoH call for water whenever it wants, not just during peak rainy seasons in the Spring and Fall. (More on that tomorrow.)
  • Many would consider preventing the potential flooding of homes a beneficial use of the water released, even if it did ultimately flow into the Gulf of Mexico.
  • We’ve heard LCA claim before that Lake Conroe won’t be able to return to its normal level in summer because of such releases. In 2021, LCA actually filed a lawsuit based on that claim. The judge ultimately dismissed the case with prejudice after SJRA had to increase release rates repeatedly that summer to keep homes and businesses around the lake from flooding.

Previous Exaggeration

In 2018, the Lake Conroe Association also claimed that seasonal lowering would destroy home values around Lake Conroe. A spot check of the Montgomery County Appraisal District site shows that many lakefront homes have actually doubled in value since lake lowering went into effect. I found one that virtually tripled.

Perhaps Lake Conroe residents are more concerned about whether their homes will flood than how far they have to step down into their boats. After all, the National Hurricane Center has predicted the most active hurricane season ever.

For More Information

To read the actual text of documents referenced in this post, follow these links:

The last includes elements of seasonal lowering, but differs in several important ways. It represents a compromise among automatic, season-long lowering and:

  • Construction delays for additional Lake Houston Gates
  • Upstream convenience and downstream risk reduction
  • Drought and water conservation concerns.

It does this by approaching lake lowering on an as-needed basis. It also specifies when the SJRA and City may bypass the protocols. See more tomorrow.

Posted by Bob Rehak on 6/24/2024

2491 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.