Lake Conroe Association Announces It Will Fight Temporary 2-Foot Lowering of Lake During Hurricane Season

A political storm is brewing with the Lake Conroe Association.

On April 26, in response to pleas from Lake Houston residents and a directive from the governor (to protect downstream residents from flooding), the SJRA board voted to lower the level of Lake Conroe temporarily. The lowering would amount to one foot during the rainiest months in spring and up to two feet during the peak of hurricane season.

The lowering would help provide a buffer against future storms by creating extra capacity within the lake to absorb rainfall before the flood gates must be opened. Thus, it will help protect Lake Houston area residents from the potential for another massive release like we saw during Harvey. However…

In an open letter posted on May 11, the president of the Lake Conroe Association says his group will NOT FIGHT a 1-foot reduction; however, he claims it MUST FIGHT a 2-foot reduction. He makes three arguments; two feet would, he says: 1) make shallow docks unusable, 2) harm tourism, and 3) reduce values of Lake Conroe homes. He says, “Families expect to enjoy their investment without SJRA and The City of Houston … ‘changing the rules.’”

The Houston Chronicle summed it up this way.

The Lake Houston Area Grass Roots Flood Prevention initiative has contacted the LCA president. We have offered to give him a tour of the devastation in the Humble/Kingwood area first hand.

TxDoT hopes to repair damage to the I-69 bridge by September, more than a year after Harvey. In the meantime, residents endure massive traffic jams. Photo taken on May 13, 2018.

Our hope is that once he sees what residents here are still trying recover from, he will be less inclined to fight the lowering of Lake Conroe by that extra foot during hurricane season. Stay tuned for more developments.

Posted May 15, 2018

259 Days Since Hurricane Harvey

 

 

Outlook for Tropical Disturbance: Texas Clear, But Not Florida

National Hurricane Center has issued a Special Tropical Weather Outlook this afternoon for the area of disturbed weather over the eastern Gulf of Mexico.

An area of showers and thunderstorms has become slightly better organized today. Global forecast models continue to suggest that this area will gradually develop into a tropical or sub-tropical cyclone over the eastern/northeastern Gulf of Mexico sometime between Monday and Wednesday.

A broad surface low or elongated trough is slowly forming on the eastern flank of an upper level trough located over the central Gulf of Mexico. Forecast models suggest the broad surface low will gradually intensify and drift N/NNE along the eastern flank of the upper level trough over the next 72 hours.

There remains some uncertainty on whether the system is more sub-tropical in nature (with winds and rain well away from the center) or more tropical in nature (with strongest winds and rains closer to the center). The latest European Centre for Medium-Range Weather Forecasts (ECMWF) outlook shows more of a tropical system. ECMWF predicts a surface low of 1003-1005mb making landfall over the Florida panhandle by the middle of this week.

Regardless of development or not, heavy rainfall and squalls will be impacting much of Florida over the next several days and spreading NNW along the NE/N Gulf of Mexico coast, generally east of Mississippi by the middle of the week.

The topical disturbance likely will come inland over the Florida Panhandle later this week. It is not currently a threat to the Texas Coast.

Currently the National Hurricane Center gives this system a 30% chance of development in the next 48 hours and 40% over the next 5 days. Regardless of development or not, heavy rainfall and squalls will be impacting much of Florida over the next several days and spreading NNW along the NE/N Gulf of Mexico coast generally east of Mississippi by the middle of the week.

At this time no significant impacts from this system are expected along the upper Texas coast. Surface winds Tuesday-Thursday may shift back to the ENE/NE, allowing an even drier air mass to advect into the region from the NE. Afternoon high temperatures should rise into the low to mid 90’s. Given the likely small scale nature of any system, do not expect any increase in tides of seas over the NW Gulf of Mexico.

By Jeff Lindner, Director Hydrologic Operations Division/Meteorologist

Harris County Flood Control District

Posted 5/13/18, 4:55 p.m CDT

257 Days after Hurricane Harvey

New River Gage at I-69 Will Measure Flow Accurately Despite Sediment

A new ADVM river gage is being installed at US59 at the West Fork of the San Jacinto River to more accurately predict floods.

The river gage at US59 and the West Fork of the San Jacinto River is being upgraded. A new Acoustic Doppler Velocity Meter (ADVM) should be operational by Monday, May 14, 2018, according to Jeff Lindner of Harris County Flood Control.

Concerns About Previous Gage

Some flood forecasting professionals suspected that the previous meter was not accurately predicting flood height because of several factors at this location. They felt sedimentation, scouring at the base of the bridge, backwater from Lake Houston, and unsteady stream flow all affected the “rating curve.”

How Rating Curves Work

Rating curves show the correlation between the river discharge (flow volume as measured in cubic feet per second) and the river stage (height). Velocity multiplied by the area of the cross section of the river for any given height equals the discharge rate. Such rates are expressed on a mathematical curve that correlates height and discharge.

These curves can change frequently, especially on a river where both sedimentation and scour can result in a change in the amount of flow at a location, as it does at US59.

Need for More Accurate Gage

One meteorologist suspected that – because the rating curve had shifted – we were seeing higher river levels with less water than pre-Harvey. That impacted the forecast accuracy for the Humble gage. A river forecaster noted that in the last two flood events, initial forecasts were “underdone” another indicator of a shifted rating curve.

According to the U.S. Geological Service (USGS), ADVMs are indispensable for backwater-influenced gages. The USGS in recent years has built hundreds of index-velocity gages with an ADVM for the measurement of streamflow. They are especially valuable in reaches where unsteady (varied, nonuniform) streamflow is prevalent that prevents the development of a conventional stage-discharge rating.

ADVMs deliver real-time flow data that would help us better understand what is going on with the rating curve and have more accurate forecasts for the Humble/Kingwood area.

An ADVM measures water velocity by using the Doppler principle applied to sound transmitted under water. Acoustic Doppler systems rely on SONAR, which uses sound waves to determine the distance to targets. They bounce acoustic signals of a known frequency off sediment in the water and measure the shift in frequency when the signals return. By measuring the time between the original pulse and the return signal, forecasters can compute the velocity of flow.

Velocity is crucial in computing the volume of water flowing past a measurement station. River forecasters use the formula:

Q = VA where

  • Q = quantity (cubic feet/second)
  • V = average velocity for the cross section (ft/s)
  • A = the area of the cross section of the river.

The faster the velocity for any given cross section, the more water that is flowing past that point.

Lindner cautions that although the new gage will begin collecting data immediately, it will take the river rising and falling several times to get enough data to accurately predict flow rates at different levels.

“A river is always in flux,” says Lindner. “The USGS has already published a new post-Harvey rating which takes into account sedimentation from Harvey near this location.”

Dredging along the West Fork would likely change that rating curve again. “The rating will have frequent changes over the next several months, as the shape of the river evolves both from natural and man-made causes,” said Lindner.

USGS has already sent the new post-Harvey rating for US59 at the West Fork to the West Gulf River Forecast Center to incorporate into their modeling efforts.

For those interested in learning more about gages and flood forecasting, the USGS has an excellent high-level, non-technical intro to measuring stream discharge. Scientists and engineers may be interested in a more technical discussion of the advantage of ADVM’s in developing more reliable real-time discharge estimates.

Posted by Bob Rehak, May 13, 2018

257 Days Since Hurricane Harvey

Unsettled Weather In the Gulf

Harris County Flood Control District just issued an alert about unsettled weather in the Gulf. Chances of it developing into a subtropical storm system are less than 30% at this time. But nature just issued a wake-up call to get those hurricane kits ready. Here is the exact text of the alert.

A weak low pressure center…likely sub-tropical in nature…may develop over the eastern Gulf of Mexico this week.

Overnight an area of showers and thunderstorms have developed over the southeastern Gulf of Mexico on the eastern side of a developing upper level trough over the central Gulf. Upper level winds are currently unfavorable for the continued development of any sort of surface circulation given strong wind shear aloft. However as this system drifts NNW over the next few days conditions may become slightly more favorable for the formation of either a surface or mid level center near/under the upper level trough. If this were to happen the system would likely develop some sub-tropical characteristics with most of the wind and rainfall over the eastern flank of the feature. Some of the forecast models have been showing off and on some sort of sub-tropical feature moving inland over the northern US Gulf coast by the middle of next week.

At this time development chances of a sub-tropical storm system over the NE Gulf of Mexico appear less than 30% and the formation of any “true” tropical system is unlikely. Given the current forecast model solutions a dry air mass will likely remain in place over SE TX and surface winds may become more ENE/NE by mid week should some sort of surface feature develop likely resulting in some very warm conditions by the middle of next week.

At this time no impacts are expected across SE TX or the coastal waters from anything sort of sub-tropical develop over the eastern Gulf of Mexico.

Jeff Lindner, Director Hydrologic Operations Division/Meteorologist

Harris County Flood Control District

Posted May 12 at 11:15 a.m. CDT

256 Days since Hurricane Harvey

Newly Renovated Kings Cove Luxury Apartments Sparkle in Kings Harbor

Kelsey Krueger, Kings Cove property manager, by the pool – one of the apartment community’s many amenities.

Eight months after Hurricane Harvey, the luxury 192-unit Kings Cove apartment community in Kings Harbor announced its Grand Re-opening. Every one of the 64 ground-floor units, the Club House, the Fitness Center, the Office Complex, and garages have been totally refurbished.

Kreuger shows off the newly renovated fitness center, which features more than $50,000 of exercise equipment.

“We are proud to say that we are the first luxury apartment to re-open in Kings Harbor. We updated all of the living spaces with full amenities,” said Kelsey Krueger, who is both the onsite manager and a resident of the community. “The restoration is remarkable. Everything on the ground floor is brand new with fresh attention to every detail.”

“The owners have demonstrated their commitment to the property and all of my tenants and fellow residents,” continued Krueger.

The complex has several incentives to entice people to return. “We are offering one month free plus move-in specials,” says Krueger.

“The grand re-opening of Kings Cove is already bringing in new residents who are helping to reinvigorate and revitalize the entire Kings Harbor area. Restaurants are coming back, too; Sharkey’s may be back by July and Raffa’s by August,” said Krueger.

For more information about the apartments and/or leasing, email Krueger, call (281) 360-1400, or visit 4920 Magnolia Cove Drive in Kingwood. The office is open until 6 p.m. daily.

Posted May 11, 2018
255 days since Hurricane Harvey

New River Gages Will Improve Forecast Accuracy and Warning Time

New upstream river gages will improve accuracy of forecasts and provide more warning time in advance of floods.

The Harris County Flood Control District (HCFCD) will begin installing several new river gages this month. They should improve the accuracy of forecasts and the warning time we receive in advance of floods. HCFCD plans to install four new gages upstream of the Humble/Kingwood area and one in Lake Houston. In addition, one of HCFCD’s current gages already in Kingwood will be replaced and relocated to a new position.

New Locations for River Gages

According to Jeff Lindner, Director Hydrologic Operations, Division/Meteorologist of HCFCD, the five new river gages will be installed at:

  • West Fork of the San Jacinto River at SH 99
  • Peach Creek at FM 2090
  • East Fork of the San Jacinto at 2090
  • Caney Creek at FM 2090
  • FM 1960 over Lake Houston

Replacement for Kingwood Country Club Gage

Lindner also says that an existing river gage on the West Fork of the San Jacinto at Kingwood Country Club will be replaced and move about a mile downstream to the West Lake Houston Parkway bridge. HCFCD will remove the Kingwood Country Club gage once the West Lake Houston Parkway gage is fully operational. The country club gage has had reliability problems. Historical data from the country club gage will also be migrated to the database associated with the West Lake Houston Parkway gage.

Linked to Harris County Flood Warning System

The new river gages will give forecasters a more complete picture of what is happening within the San Jacinto watershed during floods. They will be tied into the Harris County Flood Warning System, which shows rainfall totals, channel status and water levels at different locations. The additional gages should also play a role in future enhancements of the flood warning system, such as near real-time inundation mapping and roadway flooding.

Posted by Bob Rehak on May 10, 2018 

254 Days since Hurricane Harvey

Army Corps Completes Value Engineering Phase of West Fork Dredging Project

The U.S. Army Corps of Engineers (USACE) has posted a new video to YouTube that discusses the value engineering phase of its emergency dredging project on the West Fork of the San Jacinto River.

Galveston District Engineer Jacob Walsdorf narrates the results of a three-day event. It included hydraulic engineers, contracting representatives and project managers.

Purpose of Value Engineering

To reduce flood risks, engineers captured data from survey teams and aerial views, and utilized hydraulic modeling software to better understand areas needing dredging. In value engineering, these professionals work together to examine various scenarios that help them determine where they can achieve the greatest benefit for the lowest cost.

Previously, USACE measured sediment levels and finished field work for its initial sedimentation survey in April. It then conducted a helicopter tour of the area to provide visual confirmation of their measurements and help scope the project.

Likely Areas for Dredging

The value engineering video is less interesting for what it says than for what it shows. Approximately 48 seconds into it, the video zooms into a computer screen that shows “hot spots” referenced in earlier press releases. These represent potential dredging and disposal sites and are consistent with the problem areas identified on my helicopter tour.

The value engineering study concluded May 4, 2018. The completion of value engineering now allows Corps officials to begin the contracting process for the dredging project. See the video below.

Unconfirmed reports printed elsewhere state that USACE hopes to begin the dredging project during the second week in June.

Footage shot Mark Williford, USACE Galveston Public Affairs Chief

Posted 5/9/2018 by Bob Rehak

Day 253 since Hurricane Harvey

Take a Video Tour of the West Fork via Helicopter with the Army Corps

 U.S. Army Corps of Engineers’ (USACE) hydraulic engineers conducted an aerial tour of the West Fork of the San Jacinto River aboard an Army Blackhawk helicopter. USACE Galveston’s hydraulic engineer Michael Garske narrates the video tour, which is fascinating for its candidness.

Objectives

The tour’s objectives: to better understand the area’s dredging needs and to  scope out possible locations for storing the spoils.They identified numerous areas with excessive shoaling that contribute to area flooding and require dredging. Engineers estimate they will need to dredge from 1 to 3 million cubic yards.

Sand weighs about 100 pounds per cubic foot. So a cubic yard (27 cubic feet) would weigh almost a ton and a half. Three million cubic yards of sand would completely fill two and a half Astrodomes.

Results not yet final

So where would they put all this dredged material? Nothing is final yet. But it’s interesting to hear the engineers’ comments as they fly over random locations. See the video tour here.
According to reports from Harris County Flood Control, which is coordinating with USACE, the project is slated to start on June 8 and suppliers are being told they need to complete the project within a year.

Various Possible Scenarios Previously Examined

Here are some scenarios based on data from Brown & Root’s 2000 report on dredging, courtesy of David Seitzinger, a Kingwood engineer.  Seitzinger points out that Brown & Root also looked at dredging the West Fork. At the time, Brown & Root estimated that it would take 90 to 120 days to bid and mobilize the project. They estimated that one dredge could remove 5,000 cubic yards per day.

If that formula still holds true, a million cubic yards (the low end figure quoted by USACE) could be removed in 100 days using two dredges. If they need to remove 3 million cubic yards, two dredges would take 300 days.

Seitzinger looked at other options, too. Adding a third dredge cuts dredging time by a third – roughly two months to 200 days depending on volume removed.

Using 3 dredges could complete the project by mid-September – the peak of hurricane season – if they only need to remove 1 million cubic yards. That’s the best case scenario.

Worst case? Using two dredges to remove 3 million cubic yards would complete the project around the end of May in 2019.

Of course none of this considers weather stoppages for hurricanes and other flooding rains.  “Obviously the more dredges they can get in the river the better,” says Seitzinger.

The Army Corps plays a central role in many of the ongoing projects that affect Lake Houston. Please note the public-facing information sources that contain updates on their projects, including those in the Lake Houston area.

Online: www.swg.usace.army.mil
DVIDS: www.dvidshub.net/units/USACE-GD
Twitter: www.twitter.com/USACEgalveston
Facebook: www.facebook.com/GalvestonDistrict

 
Posted May 5, 2018
 
248 Days since Hurricane Harvey
 

Harris County to Vote on $2.5 Billion Flood Bond Referendum on Harvey Anniversary

On May 1, Harris County Commissioner’s Court unanimously approved holding a special election on August 25, 2018 for a $2.5 billion flood-bond referendum. August 25th is the anniversary of Hurricane Harvey which affected an estimated 150,000 structures in the region according to FEMA. Ninety thousand of those structures, 60 percent, were outside the 500 year flood plain.

Harris County, TX logo

Clearly, Harris County needs to improve drainage. County Judge Ed Emmett says that money in the bond referendum will address needs in all of the Harris county’s 22 watersheds. However, an exact list of projects included in the bond has not yet been defined.

Guiding Principles for Flood Bond

Judge Emmett says he is committed to both transparency and equity in the flood bond package. Historically, the Humble/Kingwood area has been underfunded. The first report by the Greater Houston Flood Mitigation Consortium found that this area contains 3 percent of the region’s population, sustained 14 percent of the region’s damage during Harvey, and historically has received zero percent of the region’s funding. It’s not zero dollars, but the dollars are so small, they get rounded down to zero percent.

What the Flood Bond Includes

Language in the draft bond proposal states in part, “The proceeds from the Bonds will be used for projects to hold or convey storm water, including land acquisition, including buyouts, and the design and construction of reservoirs, detention/retention ponds, channel improvements, restoration, and other improvements (“Flood Protection”) within the following watersheds and their tributaries…” The list of watersheds and tributaries includes the San Jacinto river and three of its tributaries including Cypress Creek, Spring Creek and Luce Bayou.

The proposed bond would increase county taxes a maximum of approximately four cents per $100 of assessed valuation. 

This Houston Chronicle article explains more about the flood bond proposal.

Improvements This Area Could Use

If, at this time, I were compiling a list of local projects to mitigate our area’s flooding, the projects would include:

  • Additional upstream detention
  • Additional dredging not currently being covered by the Army Corps, i.e., the East Fork and internal drainage ditches
  • Additional gauges to provide earlier and more accurate warnings before the next flood
  • Adding tainter gates to the Lake Houston dam, to lower the level of the lake in anticipation of major storms, so that we can shed water faster and earlier to provide an additional buffer against flooding
  • Partnering with the SJRA on projects that their watershed-wide flood prevention study identifies, especially those that can help the greatest number of people.

Others may have different opinions. What do you think? Contact me through the web form on the contact page.

Posted by Bob Rehak

May 3, 2018, 247 days since Hurricane Harvey

 

FloodWarn Workshop Presentations Now Online

If you missed the FloodWarn Workshop at Kingwood College on 5/1/18, you missed a lot of helpful information. All four FloodWarn Workshop presentations are now posted in one PDF in the reports section of this web site or via this link.

National Weather Service

Distribution Map

Rainfall during Hurricane Harvey

Katie Landry-Guyton, Senior Service Hydrologist/Meteorologist from the National Weather Service-Houston/Galveston office, talked about various types of floods, then focused on river flooding. She discussed the various types of forecasts and warnings NWS has to help you understand levels of risk. She also discussed details of how NWS formulates forecasts. For weather wonks and flood victims, it’s a must-see.

Harris County Flood Control

Jeff Lindner, Meteorologist/Director, Hydrologic Operations Division of the Harris County Flood Control District then discussed the hydrology of Harris County. Within this context, he addressed four types of floodplains in the county, the District’s flood warning system (FWS), inundation mapping/ forecasting down to the street level, and expansion of the District’s gage network.

San Jacinto River Authority

Jace Houston, General Manager of the San Jacinto River Authority (SJRA), talked about the dam operations at Lake Conroe. Specifically, he explained how they made the decision to start releasing water during Harvey. Houston also introduced the SJRA’s new regional flood management initiative.

FEMA

Rounding out the evening, Diane Cooper of FEMA Floodplain Management and Insurance. Cooper, who has posted several times on this blog, is a Kingwood resident. She focused on flood risk, hazard mapping and flood insurance.

Among the surprising facts cited:

  • The National Flood Insurance Program processed 26,511 claims as a result of Harvey.
  • 55.2% of those claims came from OUTSIDE of the 100 year flood plain.
  • Only 17% of Houstonians had flood insurance (about 1 in 6)
  • 30,500 structures were in the 1% risk area (100 year flood plain)
  • 29,000 structure were in the 0.2% risk area (500 year flood plain)
  • City-wide, Harvey impacted approximately 150,000 structures
  • That means that more structures were impacted outside the 0.2% Risk Area than inside, approximately 90,000.

Cooper cited this last point as the reason why everyone should have flood insurance whether they are officially in the flood plain or not. This was a common theme all night among all four presenters.

They also pointed out that not all flooding comes from rivers. Much flooding comes from streets. Streets in Kingwood are designed as part of the flood retention system. They can deliver approximately two inches of rainfall per hour through the storm drains to the ditches. When the rainfall rate exceeds that, drains will back up into streets and release the water slowly so as not to overwhelm the ditches.

Moral of the story: even if you’re nowhere near the river or a drainage ditch, you can still flood from your street and, therefore, need flood flood insurance.

For more interesting tidbits, download and review all four FloodWarn Workshop Presentations.

Posted May 2, 2018

246 Days Since Hurricane Harvey