Panama Canal

===Water issues===
[[File:Gatun locks showing the "mule" locomotives at work.jpg|thumb|Gatun locks showing the [[Panama Canal locks#Mules|"mule" locomotives]] at work]]
Gatun Lake is filled with rainwater, and the lake accumulates excess water during wet months. For the old locks, water is lost to the oceans at a rate of {{convert|101,000|m3|e6usgal acre-foot|sigfig=3|abbr=unit}} per downward lock movement.<ref name="PCA14">{{cite web |title=Physical characteristics of the waterway |url=https://pancanal.com/eng/noticiero/canal-faqs/physical/14.html |publisher=Panama Canal Authority |access-date=2023-08-26 |archive-url=https://web.archive.org/web/20011014101214fw_/http://www.pancanal.com/eng/noticiero/canal-faqs/physical/14.html |archive-date=2001-10-14 |date=2001 |quote="How much water is required to fill a lock chamber? Each lock chamber requires 101,000 cubic meters of water. An average of 52 million gallons of fresh water are used." |url-status=dead}}</ref> The ship's submerged volume is not relevant to this amount of water.

During the [[dry season]], when there is less rainfall, there is also a shortage of water in Gatun Lake.<ref>{{Cite news|url=https://www.nytimes.com/2019/05/17/climate/drought-water-shortage-panama-canal.html|title=What Panama's Worst Drought Means for Its Canal's Future|last=Fountain|first=Henry|date=2019-05-17|work=The New York Times|access-date=2020-01-02|language=en-US|issn=0362-4331|archive-date=January 2, 2020|archive-url=https://web.archive.org/web/20200102175814/https://www.nytimes.com/2019/05/17/climate/drought-water-shortage-panama-canal.html|url-status=live}}</ref>

As a signatory to the 2000 [[United Nations Global Compact]] and member of the World Business Council for Sustainable Development, the ACP developed an environmentally and socially sustainable program for expansion, which protects the aquatic and terrestrial resources of the canal watershed. The expansion uses three water-saving basins at each new lock, diminishing water loss.  It also preserves freshwater resources along the waterway by reusing 60 percent of water from the basins in the locks in each transit.<ref>{{Cite journal|last1=Alarcón|first1=Luis F.|last2=Ashley|first2=David B.|last3=Sucre de Hanily |first3=Angelique|author4-link=Keith R. Molenaar|last4=Molenaar|first4=Keith R.|last5=Ungo|first5=Ricardo|date=October 2011|title=Risk Planning and Management for the Panama Canal Expansion Program|journal=Journal of Construction Engineering and Management |volume=137|issue=10|pages=762–771|doi=10.1061/(ASCE)CO.1943-7862.0000317}}</ref>[[File:Mule in the Miraflores Locks.JPG|thumb|''Mule'' in the Miraflores Locks]]The mean sea level at the Pacific side is about {{convert|20|cm|in|0|abbr=on}} higher than that of the Atlantic side due to differences in ocean conditions such as water density and weather.<ref>{{Cite web |title=Frequently Asked Questions |url=https://psmsl.org/train_and_info/faqs/ |access-date=2023-05-01 |website=psmsl.org}}</ref>

The 2015-16 fiscal year was one of the driest periods on record, restricting ships passage;<ref name="wp20230824">{{Cite news |last=Sheridan |first=Mary Beth |date=2023-08-24 |title=Traffic jam at Panama Canal as water level plummets |language=en-US |newspaper=Washington Post |url=https://www.washingtonpost.com/world/2023/08/24/panama-canal-ship-backup/ |access-date=2023-08-25 |issn=0190-8286}}</ref> 2019 was the fifth driest year for 70 years. Temperature rise has also caused an increase in evaporation.<ref name="wired">{{Cite magazine |last=Jocelyn Timperley |date=2020-01-15 |title=The Panama Canal is running out of water |language=en-GB |magazine=Wired UK |url=https://www.wired.co.uk/article/panama-canal-climate-change |access-date=2023-08-25 |issn=1357-0978}}</ref> In normal times, 36 ships can transit the canal each day, but in early December 2023, ships were backing up because only 22 ships per day could transit due to low water levels.<ref>{{Cite web |last=Yerushalmy |first=Jonathan |date=22 December 2023 |title=Changing climate casts a shadow over the future of the Panama Canal – and global trade |url=https://www.theguardian.com/environment/2023/dec/22/changing-climate-casts-a-shadow-over-the-future-of-the-panama-canal-and-global-trade |access-date=22 December 2023 |website=The Guardian}}</ref> In January 2024, 24 ships per day were allowed to transit.<ref>{{Cite web|date=15 December 2023|title=Panama Canal to increase daily transits to 24 starting in January |url=https://pancanal.com/en/panama-canal-to-increase-daily-transits-to-24-starting-in-january/|access-date=29 December 2023 |website= Panama Canal Authority}}</ref>