New flood maps tell us we aren’t do­ing enough to stop ris­ing wa­ters

Chicago Sun-Times - - OPINION -

More than a cen­tury and a half ago, our low-ly­ing city launched an am­bi­tious un­der­tak­ing to raise its build­ings, streets and side­walks by sev­eral feet to make room for sew­ers and to re­duce flood­ing.

Now, a new model shows it’s time for an­other am­bi­tious un­der­tak­ing. The model, cre­ated by a group of aca­demics and ex­perts called the First Street Foun­da­tion, says the city of Chicago has the na­tion’s largest per­cent­age of prop­er­ties that are un­ex­pect­edly prone to flood­ing.

Clearly, Chicago — and the rest of the re­gion, for that mat­ter — has to step up quickly to re­duce flood­ing and pro­tect its in­hab­i­tants and busi­nesses. In an era of cli­mate change, ris­ing water lev­els aren’t a prob­lem lim­ited to the coasts.

As re­ported in the New York Times, Chicago has 75,000 prop­er­ties that are at risk of flood­ing, even though they don’t show up that way on Fed­eral Emer­gency Man­age­ment Agency maps. En­gle­wood, for one, is par­tic­u­larly vul­ner­a­ble.

FEMA says 0.3% of Chicago prop­er­ties are at risk of flood­ing, but First Street says that num­ber should be 12.8%. And this is in a me­trop­o­lis that al­ready has over­flow­ing wa­ter­ways, flood­ing base­ments, back­yards that turn into lakes and roads that dis­ap­pear un­der­wa­ter at times of heavy rains.

The same can be said of other parts of Cook County and the col­lar coun­ties, ac­cord­ing to First Street. You can as­sess your own home’s flood risk by go­ing to the First Street web­site at flood­fac­tor. com.

The en­tire re­gion is pay­ing for do­ing too lit­tle to con­trol flood­ing.

The dam­age in re­cent years has run into bil­lions of dol­lars.

The Lake Michi­gan shore­line also will be at risk if water lev­els — now near record lev­els — keep ris­ing.

“Ur­ban flood­ing is a huge is­sue for Cook County,” Kari K. Steele, pres­i­dent of the Metropoli­tan Water Recla­ma­tion Dis­trict, said Thurs­day. “Even with hav­ing the ca­pac­ity to store over a bil­lion gal­lons of water, we still have an is­sue with res­i­dents get­ting water in their base­ments.”

An­other re­cent re­port by Pro Publica said FEMA un­der­es­ti­mates flood risk be­cause in­suf­fi­cient fund­ing means many FEMA maps show­ing flood-prone ar­eas haven’t been up­dated for decades. The Cen­ter for Neigh­bor­hood Tech­nol­ogy says most flood­ing now oc­curs out­side FEMA’s of­fi­cial flood zones.

More­over, many storm sew­ers are de­signed for “100-year storms,” which are so se­vere they should hap­pen only once in 100 years. But as storms get a stronger, the 100-year storms be­come more fre­quent.

When peo­ple buy homes, it’s not ob­vi­ous to them that storm sew­ers built years ago are too small for heav­ier storms that now oc­cur be­cause warmer air can hold more mois­ture. The sew­ers sim­ply can’t carry all that water away fast enough, even if there is ca­pac­ity in reser­voirs and tun­nels, and base­ments flood.

The Metropoli­tan Water Recla­ma­tion Dis­trict’s am­bi­tious Tun­nel and Reser­voir Plan, of­ten called the Deep Tun­nel, has been a step for­ward, but even when it is fin­ished in 2029, heav­ier rains will al­ready have in­creased the need for more water re­ten­tion.

But the an­swer isn’t just to draw newer, more ac­cu­rate maps. The re­gion needs a wide­spread, co­or­di­nated ef­fort to man­age rain­fall by us­ing tech­niques that help it soak into the ground in­stead of run­ning into the near­est storm sewer.

To re­duce the amount of water flow­ing into storm sew­ers and wa­ter­ways, mu­nic­i­pal­i­ties have in­stalled per­me­able pave­ment, build­ing own­ers have put up green roofs and home­own­ers have put in rain bar­rels and rain gar­dens. This sum­mer, the MWRD is ac­cept­ing ap­pli­ca­tions from lo­cal mu­nic­i­pal­i­ties and pub­lic agencies to part­ner in in­stalling green in­fra­struc­ture through­out Cook County.

But the ef­forts so far are too much like the prover­bial drop in the bucket, and projects by one mu­nic­i­pal­ity can be un­der­mined by neigh­bors with lax reg­u­la­tions. We need stronger reg­u­la­tions, more in­ter­gov­ern­men­tal co­op­er­a­tion and wide­spread use of an ar­ray of en­gi­neer­ing tech­niques that re­duce runoff to man­age­able lev­els.

To de­velop a co­he­sive ap­proach, as the Sun-Times re­ported in May, the Al­liance for the Great Lakes, the Chicago Depart­ment of Plan­ning and De­vel­op­ment, the Chicago Metropoli­tan Agency for Plan­ning, Friends of the Chicago River, the Cook County For­est Pre­serve Dis­trict, the Lake County Stormwa­ter Man­age­ment Com­mis­sion, the MWRD and other groups are cre­at­ing a Chicago River Wa­ter­shed Coun­cil to de­sign ways to ex­pand green in­fra­struc­ture across the wa­ter­shed and to ex­pand and re­store nat­u­ral ar­eas, which should help re­duce flood­ing. We need to see more of this kind of think­ing.

We now know we are at more risk of flood­ing than we thought. Let’s get to work.

FEMA SAYS 0.3% OF CHICAGO PROP­ER­TIES ARE AT RISK OF FLOOD­ING, BUT FIRST STREET SAYS THAT NUM­BER SHOULD BE 12.8%.

ASH­LEE REZIN GAR­CIA/SUN-TIMES

Tomb­stones sit in stand­ing water on May 18 at Bo­hemian Na­tional Ceme­tery, 5255 N. Pu­laski Rd.

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