Sometime in the late evening of Memorial Day, 2015, and into the wee hours on May 26th, much of Houston flooded. Most of the news centered around spectacular vistas of Brays Bayou overflowing and inundating homes in Meyerland or the confluence of Buffalo and White Oak Bayous forming an “ocean” of water near downtown. As spectacular as those were, many other areas flooded, including the area around Memorial City TIRZ. A similar rain event in 2009 had prompted the formation of this organization. Most of the same homes flooded in the recent event that flooded in 2009; some flooded that hadn’t before, and some were dry this time, although many that were dry had been rebuilt with higher slab elevations. Many of you will be asking us one of two questions: 1) Why did you stop the lawsuit in the first place? and 2) Why restart it now?
When we stopped the lawsuit, Houston was in the throes of a drought and nearly everyone was praying for rain, not donating money to stop flooding. Our funding depends upon contributions from the public and like the parched ground, our donations had dried up. Although Jim Blackburn’s legal team had our claims identified and our legal arguments solidified, to move forward we would need enough money both to file the lawsuit and to fend off the onslaught of legal actions from the City that our lawsuit would prompt. Unfortunately, some of the claims also required a new flood event to re-trigger a two-year statute of limitations. I have often quoted statistics that Houston typically has a 100-year event every 5 years and a 500-year event every 8 years – this one took just over 6 years. It wasn’t a matter of if the next flood would occur; it was when.
We didn’t feel badly about stopping our lawsuit because former District A CM Helena Brown and District G CM Oliver Pennington were able to successfully remove the TIRZ Chair and Co-Chair while appointing true neighborhood representatives: Reverend Bob Tucker and John Rickel. TIRZ 17 seemed to have begun to seriously address flooding issues and it seemed reasonable to take a hiatus and work with John and Bob to move projects along that are important to our neighborhoods.
So why have we restarted it now? Contrary to the obvious – that homes flooded again – there are some real concerns with recent TIRZ projects and direction. There are four primary reasons: 1) the failure to enforce covenants in the Purchase and Sales Agreement between KFD LTD and the Memorial City Redevelopment Authority for the W140 detention pond property; 2) the failure of Metro National’s engineering consulting firm to provide truthful information regarding operation of the Conrad-Sauer detention pond; 3) the City’s insistence that the Gessner Road reconstruction project move forward with no place for the additional water to go; 4) failure to acquire land for new detention facilities.
W140 Detention Pond
Early on May 26th, 2015, TIRZ Board member, Bob Tucker, took photographs of the W140 detention pond. He said there was a continuous sheet of water across both the W140 pond and the “Costco” detention pond. Clearly the detention pond had worked… or had it? Could the water have come from south of the pond rather than from the Briar Branch channel? We think that it did and here’s why.
In the September 7, 2011, Purchase and Sales Agreement between KFD LTD and the Memorial City Redevelopment Authority for the W140 detention pond property, Section 11 (a.)(v.) Detention Capacity for Adjacent Property states that “the Detention Facilities will provide for up to three (3) acre-feet of detention (the “Adjacent Property Detention Requirement”) in the detention pond required for development of and necessary for use by the Adjacent Property, and will include infrastructure and related connections and appurtenances up to the common boundary line between the Property and the Adjacent Property to route runoff from the Adjacent Property to the detention pond for future tie-in to the Detention Facilities from the Adjacent Property. Purchaser’s consultants have calculated the Adjacent Property Detention Requirement as set forth in Exhibit H attached hereto based on the assumptions set forth therein; however, Purchaser makes no representation or warranty to Seller with respect to such calculation.”
Appendix H essentially states that the remaining property is 372,897 sq ft of which 251,251 sq ft is pervious. Because 121,646 sq ft is “grandfathered,” they will need to provide detention for 50% of the pervious property, or 2.88 acre-feet, which was rounded to 3 acre-feet. Unfortunately, the contract is rather lopsided. There are all sorts of remedies for the seller if the Redevelopment Authority doesn’t uphold their part of the contract, but little to nothing if KFD LTD doesn’t. Despite what they’re supposed to put into the pond, the reality is the water doesn’t care whether it’s “grandfathered.” Water is still going to flow off 8.5 acres, and if it’s all concrete, 100% of the water will be captured by the high-flow drainage system to be delivered to the detention pond. Plus, we tend to ignore that the pond itself will capture its own 8 acres of water. Always ignored by engineers in their calculations, the rainfall captured by the pond itself must be subtracted from its overall capacity.
Another problem is that the average elevation for the property was between 76 and 77 feet. Now the property nearly matches the Lowes’ property elevation, which is about 80 feet. The topographical map below illustrates the problem. The entire property was elevated. If it hadn’t been elevated, the entire property would have been flooded on May 25. Water that would have been captured on the property has now been displaced. Assuming the average increased elevation was 3 feet, the displaced water volume is over 25 acre-feet. Ignoring grandfathering for the moment and adding only the 3 acre-feet for 100% impervious cover that they can legally use means that the total displaced water is 28 acre-feet. If 4 feet of fill dirt was added to the property, the amount of displaced water swells to 37 acre-feet. Even if the average elevation increase is only 1 foot, over 11-acre-feet of detention would be needed. Where did the water go that had been displaced? Into the 44 acre-foot W140 detention pond!
At the November 13, 2014 Spring Branch West Super Neighborhood (SBWSN) meeting, TIRZ 17 presented early plans for reconstructing Briar Branch Creek. When asked what the current Level of Service (LOS) for Briar Branch Creek is, Gary Struzick, hydrologist and Vice President of Klotz and Associates, said that it was somewhere around a 5-7 year LOS. That LOS is dramatically lower than previous assessments, but better matches the recent experiences of people in the neighborhood. It means that water begins coming out of the creek when a rain event exceeds a 5-7 year LOS. For reference, the May 25 event was somewhere between a 50 and 100 year event for a rainfall with a 6 hour duration.
Why is this important? It’s important because Harris County Flood Control had told TIRZ 17 that they could not replace the Bunker Hill bridge until the W140 detention pond was built because it acts as a restrictor. If the bridge act as a restrictor and the LOS for the creek is 5-7 years, then the bridge passes less than a 5-7 year LOS. Edward Conger, the Klotz and Associates engineer assigned to manage the W140 project, reiterated that the bridge restricts the water flow at a TIRZ 17 special meeting held on June 4th, 2015. On page 3, item 5, of a letter sent on June 16th, 2014, to TIRZ 17 from the City of Spring Valley, hydrologists from Gay Engineering point out that the weir has been set at an elevation of 73.5 feet msl and that the current water elevation in a 10-year event is 74.08 feet msl. Since the channel has less than a 7 year LOS and the bridge much less than that, it is doubtful if any water from west of the Bunker Hill bridge will overtop the weir before flooding occurs. Therefore, it seems certain that all the water in the detention pond from rainfalls less than a 7-year event come exclusively from south of the pond. While water levels build in the channel, water flows freely into the pond from elsewhere.
Although Phase 2 of the Briar Branch Creek reconstruction project will add a substantial amount of detention in the W140 channel itself, Gary Struzick told SBWSN that it would only raise the W140 to a 10-year LOS. Keep in mind that the LAN Briar Branch Creek Drainage Report from 2009 said that the W140 channel had a 100-year LOS in most places and a 50-year LOS in the remainder. Either the report was incorrect or the elevation of commercial properties in the area has substantially altered to amount of water entering the channel. If funded by TIRZ 17, Phase 3 of the Briar Branch Creek reconstruction project would install additional drainage lines in the neighborhoods between W140 and Westview to improve water removal up to the 10-year event. Above the 10 year event, there will be minimal benefit. Land for more detention must be found.
On page 2, item 2, of a letter sent on June 16th, 2014, to TIRZ 17 from the City of Spring Valley, hydrologists from Gay Engineering write that the elevation of the conduits connecting W140 east and west portions that conjoin W151 by approximately 7 feet, which they claim will divert the majority of water from W151 into the W140 channel. Furthermore, they claim that water will backflow from I-10 north in the W151 into the W140. Lowering the elevation of the W140 conduits with respect to those in the W151 will improve drainage along W151, but further inundate neighborhoods along W140. Detention must be placed north of the conjunction of the two systems to prevent increased flooding.
Detention was identified on Westview Drive that could have been configured to contain up to 84 acre-feet of water. A cost benefit analysis was done which showed much less than a 1:1 cost benefit ratio largely because assumptions were made about how much water would be captured in the W140 detention pond and in the W140 channel. Removing this water should have removed houses from flooding so these weren’t counted in the benefits category. Now we know the W140 pond is not working and the benefit of a significantly larger pond would have been tremendous. Future cost benefit analyses should not include homes removed by the W140 channel until the “straws” are added. At this point it’s dubious that the W140 detention pond is adding any benefit to the neighborhood.
Conrad-Sauer Detention Pond
In the 29th, 2014, meeting of TIRZ 17, political local and state officials lined up to speak during the public comments session. Those who regularly attend meetings were dumbfounded by the praise being heaped upon the TIRZ for something never discussed publicly before.
This was the conversion of the Conrad-Sauer detention pond from an only partially working concrete bathtub into a green oasis with hike and bike trails and an additional 44 acre-feet of detention. It was a win for the commercial developer, a win for the people who love parks, and a win for people (like us) who want all the detention they can get. Trouble is it wasn’t the truth. The pond functions just fine. The pumps, however, turn on when it’s half full and empty it out into the TxDOT I-10 drainage system, which then empties into the too-small pipes under Memorial City that feed W151. The I-10 feeder roads flood every time the pumps are turned on. That system really is broken. The pumps can be reprogrammed.
At the January 27, 2015 TIRZ 17 meeting, Wayne Klotz said, “The developer (of the property at the NW corner of Gessner and I-10) provided access, at no charge to the TIRZ, of a large volume of water to get out of Gessner over into the Conrad-Sauer, which it doesn’t do now.” In other words, the Conrad Sauer detention pond is being repurposed to hold Gessner water.
The copyrighted pictures in this post were taken by Roberta Prazak the day after the flood and show the pond completely full. Wayne Klotz of Klotz and associates told the TIRZ 17 Board of Directors that the pond only operates at about half capacity (32 of 62 acre-feet).
When the public suggested that it was a pump timing issue, i.e., when the pumps start, we were told that water cannot get to the pond, “The existing Conrad-Sauer facility doesn’t function properly, primarily because the water cannot get into it, not because the pumps are not triggered properly. (20150127.301 17:17)” Apparently water can. On the night of the flood the pumps failed to turn on and so much water was able to get into the pond that it was still overflowing when Roberta snapped these photographs mid-morning the next day. Interestingly, when we filed an Open Records Request to get the Engineering Study that allowed the principle of a major engineering firm to make such a bold statement, we were stonewalled. Eventually, lawyers said that the nature of public/private partnerships precluded sharing that information with the public until the TIRZ had paid the $23M that the project will cost to the private developer.
Royal Oaks is a Spring Branch subdivision that abuts the Shadowdale ditch (W156) on its west side and lies behind the commercial businesses of Gessner on the east. The Conrad-Sauer detention pond provided a place for the City to put stormwater from Royal Oaks when they converted their open ditch drainage system to curb and gutter earlier this century. Elsewhere we’ve discussed that stormwater runoff up to a two-year event must be captured under the roadway and up to a 100-year event is supposed to be captured within the roadway right of way – both above and below ground. At the August, 2014, monthly TIRZ meeting, we learned from Klotz engineers that the Conrad-Sauer does work, but that it was only designed to hold a two-year rainfall from Royal Oaks, which only half fills it, so there’s room for stormwater from another 2-year event elsewhere – like from Gessner – to more efficiently use the space (Mayor Parker’s comment to Virginia Gregory at the September 1, 2015 City Council pop-off session). This rather absurd statement begs the question, Where does water from a 100-year event go, or even a 10 or a 5-year event?
Since the Conrad-Sauer drains the W156 watershed, water might be expected to be detained, then to flow back into the W156 ditch. Rather than drain west into the W156, it drains to the east – to the W151 system – where it tries to flow under Memorial City along with TxDOT water, Gessner water, water from Witte up to Neuens, and water from all the commercial development along I-10. Interestingly, when Lockwood, Andrews and Newman, Inc. (LAN) performed their Regional Drainage Study, the operation of the Conrad-Sauer evidently was not included in their analysis because they had a terrible time understanding why the I-10 feeder road floods so often. We don’t. We know the three Conrad-Sauer detention pond pumps just turned on. Does putting more water into the pond and turning the pumps on more frequently seem like a solution to prevent flooding? Do pigs fly?
Gessner Road Reconstruction
Water from Gessner Road was to have been diverted to the Conrad-Sauer detention basin; since it “wasn’t working,” it was underutilized and a good place to store Gessner stormwater. Clearly it is working. Moreover, two facts are now apparent: 1) the pond is being repurposed to handle Gessner water; 2) the water that presently drains into the pond sufficiently to fill it to overflowing, will now be displaced. While we cannot conduct a sophisticated analysis on the affect to the neighborhood that is drained by the pond, it seems reasonable to say that 1) either more water will remain in the neighborhood than presently does, or 2) the pumps will be turned on more often backing up water in the W140 and W151 systems exacerbating an already bad flooding situation. Until the City or the TIRZ has determined where to put Gessner water without increasing flooding, the project should be delayed.
Detention Ponds South of I-10
Several people in neighborhoods south of I-10 have complained about the lack of detention south of I-10. Although there is about 10 acre-feet under Barryknoll and 4 under Gessner, these are paltry amounts when compared to what is needed to mitigate the area’s residential and commercial impervious cover. Even new construction along Gaylord should have had detention, but has none. Knowing the problem as intimately as the developer does, it’s unconscionable that no effort was made to create local detention. Likewise, the City once again failed to enforce detention ordinances, claiming instead that every inch of the property had been covered in concrete at some time in the past. It wasn’t. This letter from a resident says it all:
Dear Mayor Parker:
Before approving the latest TIRZ 17 capital improvements plan, please ask why the proposed schedule shows improvements to Gessner north of I-10 have been pushed ahead of creating floodwater detention south of I-10.
The negative impact of commercial expansion within TIRZ 17 has been felt mostly south of the freeway, not north of it, but TIRZ 17 has done little to relieve neighborhoods south of I-10. To date, TIRZ 17 has spent over $35 million on drainage and detention north of I-10, but less than $2 million south of the freeway.
The proposed north Gessner improvements do little to help with flooding in that area and will send more runoff south of I-10. Added detention should be built south of I-10 to handle the present flows into both Ditch 151and 153 before those flows are increased. Both W151 and 153 are at capacity already and more water is only going to make matters worse. After the Memorial Day flooding events in Houston, it is hard to believe that anyone would prioritize road improvements over drainage and detention, but that appears to be what you are going to be asked to do with the TIRZ 17 Budget proposal.
TIRZ 17 long ago promised increased floodwater detention systems south of I-10 along with other drainage improvements but has not delivered them. Meanwhile, flooding in residential neighborhoods along Gessner south of I-10 is increasing because commercial developers have not been required to mitigate new-construction runoff.
Commercial development encouraged by TIRZ 17 is damaging valuable residential property, with houses that flooded now going on the market for lot value in a neighborhood where per-square-foot improvement value typically exceeds $200 and often approaches $300.
Aside from causing misery to families and putting homeowner life savings at risk, this is hurting tax valuations that benefit the city. TIRZ 17 should be required to add significant flood detention south of I-10 as was promised when the zone was created 15 years ago. Now that a viable alternative has been identified for that detention, it should be prioritized ahead of roadway improvements on north Gessner.
Please ask Public Works and Andy Icken to make drainage and detention the highest priority and ask them to prioritize the south of I-10 drainage and detention plan for TIRZ 17.
TIRZ 17 Chairwoman Givens, at a town meeting at Frostwood Elementary School, told residents south of I-10 to trust her and the TIRZ board – and by extension, City Council. Here is an opportunity to show us that we can.
Resident of Frostwood Subdivision