Tag Archive for: matt zeve

Overflow Spillways: Simple Idea to Help Keep Street Flooding Out of Homes

Overflow spillways in could have prevented many homes from flooding in May and again in September. Rain came down so fast in some neighborhoods that it couldn’t get through storm drains and into drainage ditches fast enough. Water backed up and flooded homes. I’m not talking about flooding like Elm Grove experienced from an external source. I’m talking about situations like we had in Mills Branch where approximately 25 homes flooded. They flooded, says the resident, when water backed up in the street, not because Taylor Gully overflowed.

Now Required in New Neighborhoods

Over the weekend, I corresponded with a Mills Branch resident who has anguished over what to do for months. In some cases, but not all, there may be a simple, relatively low-cost answer for the whole neighborhood. Overflow spillways. And Mills Branch might be a perfect candidate.

Matt Zeve, Deputy Executive Director of Harris County Flood Control, pointed out that regulations in newer neighborhoods now require, where applicable, overflow spillways.

How Overflow Spillways Work

These work for neighborhoods adjacent to drainage ditches, streams or bayous. The channel is built at an elevation that retains water in the street during heavy storms, but lets it flow out before it reaches the level of homes. Obviously, the street must slope toward the spillway. This wouldn’t work for homes in the middle of a block that formed a natural bowl. But assuming conditions are right…

Can Be Retrofitted to Older Neighborhoods

I asked Zeve if the Flood Control District could retrofit this concept to older neighborhoods. The answer: YES, if there’s a home between the neighborhood and the ditch that can be bought out to create space for the spillway AND if that home has flooded repeatedly.

Here are some pictures of the overflow relief spillways in place. The first goes into a retention pond.

The second goes into some woods that apparently contain a natural drainage channel.

Zeve says the Flood Control District has been buying homes and converting them to overflow spillways in key areas around the County.  These homes are in the lowest points and have flooded repeatedly.

Posted by Bob Rehak 1/6/2020, with thanks to Harris County Flood Control

860 Days since Hurricane Harvey and 109 since Imelda

Harris County Approves TWDB $30 Million Grant Application for Dredging at Confluence of San Jacinto and Lake Houston

In the last legislative session, State Representative Dan Huberty sponsored an amendment to Senate Bill 500. The amendment earmarked a $30 million grant for additional dredging at the confluence of the San Jacinto River and Lake Houston. Last week, Harris County approved the grant application to the Texas Water Development Board. That will actually transfer the money so that it can be put to work.

How $30 Million Grant Would Be Spent

County Engineer John Blount explains how the money would be spent in his cover letter that accompanied the request to Commissioners.

“The approach to completing work under the grant,” says Blount, “would be for the County to receive the grant funds, make the City of Houston a subrecipient to start immediate dredging, and to develop a long-term plan for keeping the region’s raw water supply viable with adequate reservoir capacity. The County would be reimbursed from the grant for administrative and other related expenses incurred.”

County Plays Central Role In Coordinating Effort

Blount concludes, “If authorized, the County will work with the Flood Control District, Budget Office, County Attorney, City of Houston, and the State of Texas, to advance all necessary applications and agreements needed to initiate the dredging activities funded in the 2019 legislative session. Grant awards, if made, will be presented to Commissioners Court for consideration at a future date.”

Commissioners Court approved the motion unanimously in its Tuesday, December 17th meeting. And by Friday, the actual grant application had been sent to the TWDB, according to Matt Zeve, Deputy Executive Director of Harris County Flood Control. The TWDB board should consider the request at its first board meeting in January, tentatively scheduled for the 10th. Huberty expects quick approval because the Legislature earmarked the money specifically for this purpose.

Water Supply, Not Just Flood Mitigation, An Issue

Dredging affects more than flood mitigation. It also affects water capacity for Lake Houston. The lake supplies drinking water for 2 million people. The Interbasin Transfer Project will soon bring 500,000 gallons per day from the Trinity River. But a growing East Fork mouth bar could soon block Luce Bayou. That’s where the water will enter the lake to be used by the Northeast Water Purification Plant.

As a result of sediment deposited during Harvey and Imelda, the East Fork Mouth Bar grew southward 4000 feet and now has almost reached the point where Luce Bayou and water from the Trinity River will enter Lake Houston. Photo taken 12/3/2019. Water flows from left to right.

West Fork Also Plays Role in Water Transfer

That’s also why the West Fork must remain clear. It brings water, when needed, from Lake Conroe.

Looking south across the mouth bar of the San Jacinto West Fork toward Lake Houston. Photo taken 12/3/2019.
Reverse angle. Looking northwest toward the San Jacinto River and the West Lake Houston Parkway Bridge. Note the submerged sand about to break through the water surface around the mouth bar. Photo taken 12/3/2019.
Kayaker RD Kissling standing in less-than-knee-deep water 700 yards south of the West Fork Mouth Bar. Photo taken November, 2019.

Like icebergs, sand bars mostly exist below the surface. What you see above water is a small percentage of what exists below water.

These photos illustrate why more dredging is essential. The mouth bars form dams behind the dam that block the free flow of water and decrease reservoir capacity.

Exploring Most Cost-Effective Options for Future

Between June when the Legislature approved the money and now, the City, County and State have explored ways to work together to ensure they spend the money cost-effectively. The county hired a consultant to explore the merits of do-it-yourself dredging vs. hiring a contractor. At the moment, the partners lean toward the contractor approach. It offers long-term flexibility as they explore future needs around the lake.

In addition to the $30 million from the State, the City of Houston allocated $6 million from money left over from Harvey disaster recovery funds. The County also allocated $10 million in its flood bond for dredging.

Initial Disposal Site Already Approved

The Army Corps approved Barry Madden’s property as a disposal site for the spoils. Madden’s property is opposite River Grove Park. That puts it miles closer to the Mouth Bar than previous placement areas used by the Corps. That should reduce costs by reducing the need for booster pumps and fuel.

The pieces of the puzzle are starting to come together.

Posted by Bob Rehak on 12/23/2019

846 Days since Hurricane Harvey and 95 since Imelda

Clear Debris from Drains Before Next Wave of Rain Hits

Multiple news outlets are reporting that 400 homes flooded in the Kingwood area yesterday due to street and ditch flooding. Street flooding happens when the RAINFALL RATE exceeds the DRAINAGE CAPACITY of storm sewers. Water backs up into streets where it waits until the input and output balance. But when drains are blocked by downed tree limbs, yard waste, and other debris water backs up even higher into homes as it did last night.

Flooded home in Elm Grove

Please Help Clear Drains of Debris

Matt Zeve, Deputy Executive Director of Harris County Flood Control, reminds everyone that, “All citizens have a responsibility to keep their storm sewer inlets and roadside ditches clear of yard debris, trash, and other items that can cause clogging. The City of Houston and Flood Control are not able to police every single ditch and storm sewer inlet out there. We are all in this together.”

It could be your house that you save from flooding in the next rain.

How to Report Debris in Ditches

Some debris will be beyond the capability of homeowners to clear, especially in creeks and drainage ditches. For instance, see the picture below.

Tree down in Ben’s Branch. Photo taken from Tree Lane just east of Bear Branch Elementary.

Clearing such blockages will take professionals with chain saws and lifting equipment.

Call Harris County Flood Control at 713-684-4197 to report these types of issues.  Please make sure you know the closest cross streets.

You can also contact flood control via the web.

City of Houston Also Requests Your Help in Clearing Drains

Dave Martin, Houston City Council Member said, “This morning, I asked the Mayor, and he agreed, like we did in December 2017 AFTER Harvey…in those flooded/affected areas, we will send cameras down the storm drains and sewers to see if there is any blockage. If there is, we will remediate.”

Martin continued, “We are also ‘re-engineering’ our ‘Adopt a Drain’ program which calls for our Residents to adopt a drain/storm sewer in their neighborhood, and periodically check the siltation/trash/clogging/buildup in THEIR drain.

More Rain on Way

At the start of the week, the National Weather Service forecasted 7-10 inches of rain for the week. Yesterday, when a storm stalled over Kingwood, we got that much in one afternoon. And more IS on the way.

NOAA Radar as of noon on Wednesday, 5/8/19.

Today’s Forecast from Flood Control

The next upper level disturbance is already moving into central Texas. The majority of the heavy rainfall should stay to our north today, but our area could certainly see rainfall this afternoon that could result in additional flooding, especially if it falls on areas that were hard hit on Tuesday.

Additionally there is a higher severe weather risk this afternoon especially north of I-10 where large hail, damaging winds, and isolated tornadoes will be possible.

Forecast Thursday-Saturday: 

Several complexes and clusters of storms can be expected through the period each capable of dropping multiple inches of rainfall. Expect a moderate risk of flash flooding both Thursday and Friday. 

Additional Rainfall Amounts 

Widespread rainfall of 5-8 inches with isolated totals of 9-12 inches will be possible today through Saturday. While these totals are spread over a 3 day period, much of what falls will likely fall in bursts with each cluster of storms. Air mass remains very much capable of intense rainfall rates as observed yesterday. Hourly rainfall rates of 2-4 inches per hour will remain possible which will quickly result in urban flash flooding and significant street flooding.

River Report

Grounds are saturated and any additional rainfall…especially in areas that saw heavy rains on Tuesday…is going to run directly into creek, bayous, and rivers that area already highly elevated. If the rainfall forecast does indeed verify, flooding of creeks and bayous in Harris County is certainly possible along with house flooding.

While several creeks and bayous are elevated, all are receding at this time including both the East and West Forks of the San Jacinto River.  

Flash Flood Outlook For Wednesday 

Flash Flood Outlook For Wednesday 

Posted by Bob Rehak on 5/8/19 at noon

617 Days since Hurricane Harvey