Editing Chicago River (section)

==Monitoring the impact of extreme weather events on the Chicago District==
The [[US Army Corps of Engineers]] have monitored the development of harbors and channels for navigation on the Great Lakes since the early 1800s. They began monitoring hydrological conditions and lake levels in 1918. A December 26, 2012 report revealed that Chicago District navigation infrastructure did receive significant impacts from [[Hurricane Sandy]] with some areas experiencing severe shoaling. Chicago Shoreline Project mitigated the damage of the storm event.<ref name=US-Army-Corps-report />

The same report noted that the low Great Lakes levels were drought-induced, caused by a very hot, dry summer and a lack of a solid snowpack in the winter of 2012. At the time of the report, December 2012, Lake Michigan-Huron was 28 inches below its long-term average which is near the record lows of 1964.<ref name=US-Army-Corps-report /> Historic lake levels for Lake Michigan reported from 1918 to 1998 show that the low levels observed in 1964 were the lowest since 1918.<ref name="IllinoisDNR">{{cite report |url=http://dnr.state.il.us/publications/pdf/00000507.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://dnr.state.il.us/publications/pdf/00000507.pdf |archive-date=2022-10-09 |url-status=live |title=Chicago River/Lakeshore Area Assessment |date=October 2000 |publisher=Department of Natural Resources, State of Illinois |volume=2 |page=4}}{{Dead link|date=September 2019 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> In 2012 Lake Michigan-Huron's seasonal rise was about 4 inches where it usually is about 12 inches. Normally the Chicago River water level is two feet lower than the lake and therefore does not flow into the lake. If the lake level falls too low threatening to reverse the river flow, the [[Metropolitan Water Reclamation District of Greater Chicago]] would be forced to close locks between the lake and river for longer periods of time, limiting navigation. A reversal flow of the Chicago River into Lake Michigan would have a negative impact on navigation and on the quality of Lake Michigan water, which is the source of drinking water.<ref name=US-Army-Corps-report /> Chicago's raw sewage in the river is normally carried upstream toward the Mississippi River which flows south towards the Gulf of Mexico. On January 9, 2013, Chicago meteorologists announced 320 days without at least one inch of snowfall. Water levels in the lake started to level off with the river and sewage was visible at the cusp of the locks, just a few hundred feet from Lake Michigan. David St. Pierre, executive director of the Metropolitan Water Reclamation District of Greater Chicago warned the low lake levels were nearing a point of real concern.<ref>{{cite news |title=Continuing Drought Could Lead To Reversal of Chicago River Flow |url=http://chicago.cbslocal.com/2013/01/09/continuing-drought-could-lead-to-reversal-of-chicago-river-flow |date=January 9, 2013 |access-date=January 12, 2013 |archive-url=https://web.archive.org/web/20130117081511/http://chicago.cbslocal.com/2013/01/09/continuing-drought-could-lead-to-reversal-of-chicago-river-flow/ |archive-date=January 17, 2013 |url-status=live }}</ref> However, the District maintains that it is not possible for the river to reverse due to low lake level alone.<ref>{{cite press release | url=http://www.mwrd.org/pv_obj_cache/pv_obj_id_72F65FA94CB009863087446F91F6810D757B0400/filename/13_0110_Low_Lake_Levels.pdf | title=MWRD: Not possible for Chicago River to reverse on its own due to low lake level | publisher=[[Metropolitan Water Reclamation District of Greater Chicago]] | date=January 10, 2013 | access-date=January 12, 2013 | archive-url=https://web.archive.org/web/20130705060144/http://www.mwrd.org/pv_obj_cache/pv_obj_id_72F65FA94CB009863087446F91F6810D757B0400/filename/13_0110_Low_Lake_Levels.pdf | archive-date=July 5, 2013 | url-status=dead }}</ref><ref name=Fox>{{cite news |title=Drought won't affect Chicago River much after all |url=http://www.myfoxchicago.com/story/20548616/drought-wont-affect-chicago-river-much-after-all |author=Flannery, Mike |publisher=FOX 32 News |series=Chicago News and Weather |date=January 9, 2013 |access-date=January 12, 2013 |archive-url=https://web.archive.org/web/20130126180738/http://www.myfoxchicago.com/story/20548616/drought-wont-affect-chicago-river-much-after-all |archive-date=January 26, 2013 |url-status=dead }}</ref>

Measurements taken by the US Army Corps in January 2013 revealed that both Lake Michigan and Lake Huron had reached their "lowest ebb since record keeping began in 1918, and the lakes could set additional records over the next few months, the corps said. The lakes were 74 centimetres (29 inches) below their long-term average and had declined 43 centimetres (17 inches) since January 2012".<ref>{{cite news |url=https://www.cbc.ca/news/canada/windsor/lake-huron-lake-michigan-hit-lowest-water-levels-on-record-1.1380357 |title=Lake Huron, Lake Michigan hit lowest water levels on record |agency=Associated Press |publisher=Cbc.ca |date=February 8, 2013 |access-date=February 6, 2013 |archive-date=March 14, 2022 |archive-url=https://web.archive.org/web/20220314172959/https://www.cbc.ca/news/canada/windsor/lake-huron-lake-michigan-hit-lowest-water-levels-on-record-1.1380357 |url-status=live }}</ref>