John Blount is the County Engineer and leader of the Harris County Engineering Department. Steve Albert is an editorial committee member of Cite and principal with Sherwood Design Engineers, a civil engineering firm with offices in San Francisco, New York, and Houston that has performed work for Harris County. Blount spoke with Albert about flood mitigation in Houston after Hurricane Harvey.
Steve Albert: Thank you for meeting with me. Houston does not have a strong history of regional governmental cooperation. However, watersheds do not follow political boundaries. How will we develop a plan of action to address flooding issues facing the City of Houston and the cities and counties in the region in a coordinated manner?
John Blount: There is a regional coordinating council in Harris County. It is called the Harris County Flood Control District, which works with all the cities within Harris County. There are interlocal agreements between Harris County and Montgomery County to do a more regional approach. There is no doubt that watersheds don’t stop at political boundaries. There is a much larger realization of that. We were at the Council of Urban Counties a couple of weeks ago, and this topic came up. A discussion was possibly having the Texas Water Development Board do something similar with regional planning groups for [drinking and waste] water and doing the same thing with stormwater. It’s a global discussion. It doesn’t just affect Harris County and the City of Houston. It affects a lot of people. There is a lot of cooperation between local governments here. You can be in Walker County and Huntsville and impact Harris County directly. That’s not widely understood.
SA: The regional interconnections are important. That’s a unique perspective, which needs to be pursued.
JB: The Water Board was at this meeting. They are aware.
SA: Did they nod and say yes we’d like to do that?
JB: I think they understand. They do a very good job with water planning. Everyone is looking at that model.
SA: Very little damage from Hurricane Harvey or the previous major storm events occurred to structures built since the late 1990s, particularly after flood maps were updated after Tropical Storm Allison. In the interest of making Houston more resilient to flooding, Harris County and the City of Houston adopted new floodplain regulations. Are these regulations too conservative or too aggressive?
JB: I think they are appropriate. We looked at the number of houses that flooded, how deep they flooded, the age they were built, and we looked at the homes that didn’t flood. We did statistical analysis and tried to set the rules to mimic that. We think they are appropriate.
SA: So two feet above the 500-year floodplain is now the standard.
JB: Let me add one more thing. We know that National Oceanographic and Atmospheric Administration (NOAA) Atlas 14 [containing the latest precipitation frequency estimates] is coming out. It will change the floodplain elevation. We suspect the change will go up, but we don’t know by how much. The last thing we want to do is not set the standard high enough and put somebody building a new house in a condition where we knew there would be a change, and they are below the elevation they should be. Once the new maps are published, we will come back and make sure they fit where we think they should fit.
SA: There could be an adjustment away from the 500-year standard at that time.
JB: The ASCE [American Society of Civil Engineers] standard is at or above the 500-year floodplain, or 1 foot above the 100-year floodplain, whichever is higher. If we had done that, it would not protect the number we have under the current maps.
SA: The rest of the nation watching the Harvey media coverage believes that the entire region flooded and that virtually none of us were spared. They are surprised when I tell them that less than 10 percent of structures were impacted and that there was little damage to structures built since stricter regulations were adopted about 20 years ago. The outside perception of our flooding problem will have a large impact on the economic health of the region. How can we address the issue of repeat flooding of legacy structures built in flood-prone areas before we began defining floodplains in the 1980s in order to reverse this perception?
JB: That’s exactly right. I don’t know the statistics for the City of Houston. I know that ours is roughly six percent, homes in unincorporated Harris County that flooded. I think 10 percent within the city would make sense because they have more older structures. For the older homes, we need to either build flood control projects that protect them or buy them out. That’s the concept that the Flood Control District is currently working on and has published in the proposed bond program. We are going out in subdivisions that were built in the 1960s and buying a large portion of it with the intent of putting large detention ponds in them so that the remaining homes are protected. We are looking at the cost-benefit of buying homes versus putting detention and mitigation in, and we are doing the balance.
SA: New stormwater regulations will impact the cost and the availability of land that is suitable for development and will increase development and redevelopment costs. These new stormwater regulations have changed the rules for developers. What is the impact these new regulations will have on finding property to develop and completing projects that will maintain our reputation as a relatively low-cost market for housing and businesses?
JB: I would disagree that it fundamentally will change the development. Currently we don’t have developers developing subdivisions in the floodplain. As you pointed out, less than 0.75 percent of the 75,000 homes built since 2009 that met the standards set then flooded. So it is not an impact on developers, but it is a significant impact on builders and what we call non-conforming subdivisions, which are subdivisions developed prior to the 2009 rules. The City of Houston, the entire city, is almost what we would call a non-conforming subdivision. They are agreeing with that. There isn’t modern drainage infrastructure. There will be a significant impact on builders, but on developing lots, no. There will be increased cost of construction for those builders building on lots with the new rules.
SA: There was a subdivision that came to city council that was partly in the floodplain and elevated and compensated for the fill in the floodplain. There are some of those projects going on, making tradeoffs within the floodplain.
JB: It is very common to have areas shallow in the floodplain, let's say an inch. Well, they don’t want it to show in the floodplain in the maps. So they will take fill from one area that is out of the floodplain and put it there so they can take it out, so they can map it outside the floodplain. Then everybody says you are putting people at risk. The county has a whole set of standards for how high you have to be, whether you are in a floodplain or not. That’s those 2009 standards which prevent people from flooding. A lot of times it is a correction of the map. A lot of times the maps are wrong. The maps are not always based on detailed surveying that is obtained when you develop a subdivision.
SA: National media have blamed our development of vacant land and our lack of zoning as major causes of our chronic flooding. Some also claim that new development continues to exacerbate flooding. Rules recently adopted for the Barker, Addicks, and Cypress Overflow watersheds now require stormwater retention to offset the additional runoff that results from the construction of new impervious surfaces. Given that the current rules in place outside of these three watershed areas do not require new development to reduce total runoff to pre-development levels, is Harris County considering adopting these rules for the other 20 County watersheds?
JB: That’s really a Flood Control District Rule, so I don’t know about it. We have flood detention requirements when you drain from a subdivision into a county roadside ditch. They set the standards for drainage into a channel.
SA: Low Impact Development methods are now being more widely implemented in large part because of the Low Impact Development Guideline adopted by the County in 2011. The intent of these methods is to provide for stormwater systems that mimic pre-development runoff conditions. What role does Low Impact Development play in the toolbox of solutions for our flooding problem and should acquisition of the Katy Prairie or other open lands be a regional priority?
JB: Low Impact Development is another tool in the toolbox that is used, not as much as we thought it would be. More and more people are accepting it as an alternative. As far as the Katy Prairie, everybody thinks it needs to be preserved from an environmental standpoint. I don’t have an illusion that it somehow would have protected us from Harvey. That’s not the case. Those people familiar with the Katy Prairie would say the same thing. It has a substantial impact on storms when it is dry. It can take a lot of water when it hasn’t rained for a while. Aside from the flooding, it is an environmental asset that needs to be preserved. We work with the Katy Prairie Conservancy to do that.
SA: A great deal of attention has been placed on the potential benefits of building a third reservoir in the northwest part of our region. This may address some of the flooding problems in a couple of our watersheds. However, we have dozens of watersheds that experienced flooding. A new reservoir also does not address localized flooding that is separate from bayou flooding and which caused half of all the flooded structures. How do we allocate funding resources to all watersheds and non-bayou areas to achieve a maximum overall regional benefit?
JB: If someone were to look at the projects proposed under the Harris County Flood Control District bond program, there are a multitude of approaches, and it is countywide. I have heard someone say it is all going to this or that bayou. I always say, ‘that’s funny, you clearly haven’t seen the list’ because that is not the case. It is going countywide. The projects are looking at both riverine flooding, subdivision flooding where you can’t get the water to the stream, and a combination of both. Inside the city limits they have the ability to fix the internal drainage, but they don’t have the depth of outfall [the place where a river, drain, or sewer empties into the sea, a river, or a lake]. So the main channel project will fix the drainage because if there is not outfall you cannot drain the subdivision. So it is a comprehensive approach.
SA: So it combines the neighborhood drainage with the overall regional drainage. So the project list is the way to see how the funding is allocated.
JB: We are meeting with every watershed, and we evaluate every project brought to us.
SA: In a recent poll only 46 percent of Houstonians said they were willing to pay higher property taxes to help remedy the flooding issue. However, Rebuild Houston represents a successful effort to convince the public that raising fees for drainage improvements would be supported. How will the Houston region develop the funding needed to address the needs of existing infrastructure in conjunction with federal and state funding sources and is ReBuild Houston making progress on Houston's local drainage infrastructure as intended?
JB: I won’t comment about Rebuild Houston. I don’t know the statistics. I assume you are speaking to Bob Stein’s poll, which wasn’t specific to Harris County. I don’t think it was representative of our citizens. It was a multi-county evaluation. I can tell when explained --- that’s the purpose of the public meetings --- people understand why this is being proposed.
SA: There is a broad consensus that climate change may cause an increased frequency and intensity of rainfall events and a rise in sea levels. What is Harris County doing to address this issue and how does it impact the planning of large-scale projects?
JB: I will tell you, I hear arguments on all sides of the global warming issue or climate change. I have not spent any time looking into it because I have a lot of other work to do. That’s not something that local government does. We do, however, do things in conjunction with the federal government, like the current study on rainfall, to verify the intensities. Although it is raising here, in other parts of the state it is lowering. How is that explained? Is it because we have more accurate data?
I am constantly reminded of a meeting I had with local officials many years ago: The new floodplain maps came out, and they made the comment that ‘this is all due to climate change, but we don’t want to accept them because it will cost more insurance.’ I said, ‘I don’t know about the climate change, but the [old] maps are wrong, and you might as well accept [the revisions] because the 1961 Carla elevations were higher.’ People tend to forget the past. Is it getting worse, or do we have an extremely short memory? Which seems to be the case many times over. We forget how bad it really was. The truth is we did not collect the data years ago. I am not taking a position one side or another, that’s not for me to do, but I can tell you there has been a lot of data that has not been collected.
SA: Thank you for spending time with us today. I really appreciate it.