FOR THE RECORD, THIS IS HOW DEEP IT IS
Finally, May 17, 2018 saw the release of Houston’s revised 500 year flood plain map. It’s one of the fundamental documents that will decide what gets constructed, where, and how. From the contours – drawn and colored to show which areas fall below the plain’s “zero” level, and by how much – it’s easy to see why certain neighborhoods suffered so much during 2015, 2016 and 2017. Block after block of Meyerland and Bellaire lie (-1’) to (-5’) below the flood plain. Based on the map’s contours, hundreds of still-occupied homes are likely to suffer severe damage in the next big storm. Again.
What about the large scale projects – new dams, expanded bayous, large detention basins – needed to head off this foreseeable damage? The public conversation among institutions, private groups and individuals is indeed under way but tends to be somewhat inward-looking. While TED-style talks in various venues have touted vanity solutions, the reality is persistent, stolid inaction. 9 months after Harvey’s big water, the region-wide projects presumably needed for true “solutions” have not been agreed, much less funded.
VINDICATION FOR THE STORM DEFENSE HOUSE
It's important to recognize that there are good things happening – although usually at small scale. For the Category-5, Harvey’s outcome was quite positive. Only two of our Houston Category-5 type houses matched the elevation specs of a true Storm Defense House, but they both performed well during the storm. Of these, one was located in the River Oaks subdivision and saw little of Harvey’s dangerous waters. The other was located specifically to address historically high levels of flooding in Meyerland, and presented a true test of the Category-5 system.
Based on the new map, 9715 Runnymeade in Meyerland sits on ground that’s 48”+ below the 500-year flood plain. The street itself is certainly at 60”+ below zero. In September 2017, even as every building for blocks around was plunged deep into Harvey’s flood, our new construction on Runnymeade - modeled directly on Storm Defense House specifications, and elevated to 60” above grade - remained dry. The storm’s flow traveled unobstructed under the building, leaving its technology completely undamaged. Meanwhile, large public structures like Kolter Elementary School (literally, directly across the street), several houses of worship, and other public buildings in Meyerland were fatally damaged, with demolition and clearance now under way. The Runnymeade house clearly showed what a Storm Defense House can do.
LIVING APART, ACTING TOGETHER: BEATING THE FLOOD
Without institutional support for flood-resilience, Houstonians are in a situation of “every man for himself.” That means the burden of protecting their properties from the hazards of major floods falls upon them alone, as individuals. As demonstrated by the Runnymeade Storm Defense House, this need not be a recipe for disaster - however, the obvious lesson of simply raising living space to a safe elevation is only a partial answer to the storm. In fact, the Category-5 has two lessons: one for houses, house by house; and the other for neighborhoods, house by house.
For the individual's survival, each building's crawlspace should be truly “flow-through” (with break-away skirts) so there’s no pooling of flood waters or rising damp and pestilence after the flood. Exposed building surfaces within the crawlspaces should be treated with FEMA-approved closed-cell foam for insulation as well as material-protective purposes. The structure should be ready for winds above 157 mph, the threshold for Category 5 hurricanes. Exterior finishes should be inorganic whenever possible – but not masonry due to its water absorptive tendencies.
For collective survival, property owners can act together to make large scale weather-beating change. First, the ways in which construction meets the ground should be revised to better handle the water from large downfalls. The philosophy should be to “stop the raindrops where they fall,” per the Save Buffalo Bayou organization: if we can slow the flow of big weather towards overburdened conveyance systems (think: bayous and storm sewers, etc.) we can go a long way toward defeating floods via super local retention/detention. It’s simple: by arranging for storm water to move toward the bayous in slow motion, it’s possible we can limit how overburdened the bayous become, and therefore how high the waters rise, in general. Every little bit counts, to coin a phrase.
The key to citizens’ gaining ground on big weather is to consider how quite separate individual actions, performed collectively, might render a common good – such as an outright reduction of flooding. So: what does this result demand? Again, it’s simple: all parts of individuals’ homesteads should contribute to absorbing and keeping hold of rainwater. The driveway, crawlspace and “hardscape” areas should have pervious surfaces on top of vermiculite-saturated absorbent bedding. Lawns should be replaced with heavily vermiculite-mulched flower and vegetable gardens, all with continuously-terraced high profile edging to create “mini-reservoirs” – sponges, in essence. Roof water can be directed to dry wells and multiple above-ground tanks. Performed house by house by citizens working "apart, together" these tactics could divert many thousands of gallons from a rising flood. Adopted neighborhood and area-wide, they're a way to meet the storms head on, with high hopes of defeating their big water.