Description and Details

The Mer­amec Riv­er can be found curv­ing around the St. Louis sub­urbs before it joins to meet the Mis­sis­sip­pi Riv­er. These sub­urbs are direct­ly impact­ed by the riv­er when it floods except one, Val­ley Park, where it is pro­tect­ed by a $50 mil­lion lev­ee designed by the U.S. Army Corps of Engi­neers. The lev­ee has been pro­posed to increase flood­ing in the sur­round­ing sub­urbs lead­ing to more destruc­tion and deaths. 

Con­trol­ling the flood­ing on the Mer­amec riv­er has been of inter­est since 1929 when the Corps looked into con­struct­ing a reser­voir held behind a dam which would have elim­i­nat­ed flood­ing for 33 miles of the low­er Mer­amec. Ulti­mate­ly, it was decid­ed that the land it would have been pro­tect­ing was not valu­able enough for such a project. In the 1960s, the area expand­ed in pop­u­la­tion and prop­er­ty and the Corps recon­sid­ered the reser­voir but feared oppo­si­tion from local own­ers and envi­ron­men­tal­ists. The reser­voir was vot­ed on by vot­ers in St. Louis and coun­ties along the riv­er in 1978 where two-thirds opposed the project and con­gress deau­tho­rized the project in 1981. The Mer­amec con­tin­ued to flood lead­ing to more deaths and more than $100 mil­lion in dam­ages for a sin­gle flood result­ing in the Corps resolv­ing the flood­ing with an order from Con­gress with­out includ­ing dams or reser­voirs. In 1987, the Corps out­lined in a report a project that would pro­tect dozens of com­mu­ni­ties with lev­ees and oth­er solu­tions but was halt­ed due to the costs out­weigh­ing the ben­e­fits of the project. Instead, a loca­tion for a lev­ee was cho­sen using a cost-ben­e­fit analy­sis which aims to reduce the flood risk that ben­e­fits the coun­try eco­nom­i­cal­ly. This analy­sis favors high-val­ued prop­er­ties, typ­i­cal­ly found in afflu­ent com­mu­ni­ties, over less wealthy com­mu­ni­ties. Lev­ee build­ing was also often favored over oth­er solu­tions such as buy­ing prop­er­ty along the riv­er to allow it to expand dur­ing floods due to the val­ue of the near­by prop­er­ty that would be pro­tect­ed not being wor­thy enough. Val­ley Park was an afflu­ent neigh­bor­hood locat­ed in the low­est part of the flood­plain with lots of homes, schools, police sta­tions, and com­mu­ni­ty resources that were deemed wor­thy of pro­tec­tion by the Corps. To imple­ment any project, the Corps need­ed a local fund­ing part­ner to pay for a quar­ter of the costs, and Val­ley Park was the only com­mu­ni­ty able to sup­ply the funds of around $13 mil­lion when con­struc­tion began.  For ref­er­ence, the orig­i­nal reser­voir pro­pos­al would have pro­tect­ed dozens of com­mu­ni­ties and cost $70 mil­lion dol­lars in 2003 dollars.

While the lev­ee was built in 2005, it was con­struct­ed using out­dat­ed mod­els from the 90s that didn’t account for land cov­er change or cli­mate change. This result­ed in increas­ing what was only sup­posed to be a few extra inch­es of water in the sur­round­ing com­mu­ni­ties to lev­els much high­er. Addi­tion­al­ly, since the lev­ee was built high enough to pro­tect against a 100-year flood, Val­ley Park res­i­dents no longer need­ed fed­er­al flood insur­ance pro­duc­ing around $225,000 in annu­al ben­e­fits but the height of the lev­ee could be part of the rea­son why the oth­er areas flood more fre­quent­ly. As the area expand­ed, growth was noticed in the flood­plains mean­ing as space was tak­en to build homes that would have oth­er­wise been used to hold water dur­ing a flood, the riv­er was being dri­ven high­er mean­ing sur­round­ing areas could see more flood­ing in their homes. This com­bined with devel­op­ment out­side of the flood­plain has led to exu­ber­at­ed flooding. 

Since the lev­ee was built, the cal­cu­la­tions have not been checked for accu­ra­cy or used on new­er mod­els. Fed­er­al­ly fund­ed stud­ies have been pro­posed, but some claim it is a ques­tion of fair­ness where if one com­mu­ni­ty got a spe­cial study then all com­mu­ni­ties should war­rant one as well. As the area con­tin­ues to flood, sur­round­ing areas around the lev­ee con­tin­ue to rebuild and adapt to ris­ing riv­er lev­els at steep prices with some con­sis­tent­ly los­ing their homes dur­ing every flood.  Hav­ing a local lev­ee dis­trict ensures the lev­ee stays up to date with reg­u­la­tions and flood pat­terns, but local gov­ern­ments in Val­ley Park lack fund­ing to have such a dis­trict with lit­tle incen­tive to form one if it is found the lev­ee vio­lates reg­u­la­tions. Fund­ing is an issue for every­one with the Corps only hav­ing 2% of its autho­rized projects get fund­ing annu­al­ly and the USGS not hav­ing the funds to per­form effi­cient stream gauge mea­sure­ments to assist in flood risk man­age­ment.  It should be not­ed that a study was done by the Corps to offer com­mu­ni­ties impact­ed by the lev­ees non­struc­tur­al solu­tions to reduce the flood risk but those com­mu­ni­ties are respon­si­ble for imple­ment­ing any solu­tions. As one com­mu­ni­ty is pro­tect­ed, its pro­tec­tion may be lead­ing to the suf­fer­ing of its neigh­bors due to them being less afflu­ent which strength­ens the large gap of gen­er­a­tional wealth in the area. 

CEE sub­jects: Envi­ron­men­tal Engi­neer­ing, Hydraulics and Hydro­log­i­cal Engineering

Discussion Questions

  • Do you think the Army Corps could have done more in pro­tect­ing the sur­round­ing com­mu­nites from flood­ing? If yes, give an exam­ple of what could have been done and if no, give an exam­ple of what out­side groups could have done to lim­it flooding.
  • While the Val­ley Park lev­ee was built with old­er gen­er­a­tion mod­els leav­ing out impor­tant time chang­ing vari­ables, how does this project empha­size the need to think for a chang­ing future?
  • This case study can be viewed as a class issue with a more efflu­ent com­mu­ni­ty being deemed valu­able enough for sav­ing while low­er-class comu­ni­ites are left to flood. What long term impacts may this have on the com­mu­ni­ty and how can you as an engi­neer be mind­ful of wealth dif­fer­ences when per­form­ing cost-beneift analy­sis in real-world situations?

References

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