Lock Haven, Pennsylvania

=== Floods ===<!--section linked directly from [[Piper PA-24 Comanche]], please update there if section title is changed-->
[[File:Lock Haven Bridge panorama.jpg|thumb|Since 1995, a levee protects Lock Haven from the West Branch of the [[Susquehanna River]].|alt=A large, smooth river crossed by a modern bridge. The left bank is tree lined, the right is a levee, a long mountain ridge is in the background.]]
Pennsylvania's streams have frequently flooded. According to William H. Shank, the Native Americans of Pennsylvania warned white settlers that great floods occurred on the Delaware and Susquehanna rivers every 14&nbsp;years. Shank tested this idea by tabulating the highest floods on record at key points throughout the state over a 200-year period and found that a major flood had occurred, on average, once every 25&nbsp;years between 1784 and 1972. Big floods recorded at [[Harrisburg, Pennsylvania|Harrisburg]], on the [[main stem]] of the Susquehanna about {{convert|120|mi|km|sigfig=2}} downstream from Lock Haven, occurred in 1784, 1865, 1889, 1894, 1902, 1936, and 1972. Readings from the Williamsport [[stream gauge]], {{convert|24|mi|km|0}} below Lock Haven on the West Branch of the Susquehanna, showed major flooding between 1889 and 1972 in the same years as the Harrisburg station; in addition, a large flood occurred on the West Branch at Williamsport in 1946.{{sfn|Shank|1972|pp=10–13}} Estimated flood-crest readings between 1847 and 1979—based on data from the [[National Weather Service]] flood gauge at Lock Haven—show that flooding likely occurred in the city 19&nbsp;times in 132&nbsp;years.{{sfn|Schuldenrein|Vento|1994|pp=4–5|loc=chapter 2, table 1}} The biggest flood occurred on March 18, 1936, when the river crested at {{convert|32.3|ft|m}}, which was about {{convert|11|ft|m}} above the flood stage of {{convert|21|ft|m}}.{{sfn|Schuldenrein|Vento|1994|pp=4–5|loc=chapter 2, table 1}}

The third biggest flood, cresting at {{convert|29.8|ft|m}} in Lock Haven, occurred on June 1, 1889,{{sfn|Schuldenrein|Vento|1994|pp=4–5|loc=chapter 2, table 1}} and coincided with the [[Johnstown Flood]]. The flood demolished Lock Haven's log boom, and millions of feet of stored timber were swept away.{{sfn|Shank|1972|pp=22–23}} The flood damaged the canals, which were subsequently abandoned, and destroyed the last of the canal boats based in the city.{{sfn|Miller|1966|p=59}}

The most damaging Lock Haven flood was caused by the remnants of [[Hurricane Agnes]] in 1972. The storm, just below hurricane strength when it reached the region, made landfall on June 22 near New York City. Agnes merged with a non-tropical low on June 23, and the combined system affected the northeastern United States until June 25. The combination produced widespread rains of {{convert|6|to|12|in|mm|0}} with local amounts up to {{convert|19|in|mm|0}} in western [[Schuylkill County, Pennsylvania|Schuylkill County]], about {{convert|75|mi|km|0}} southeast of Lock Haven.<ref>{{cite web| url =http://www.wpc.ncep.noaa.gov/tropical/rain/agnes1972.html|title =Hurricane Agnes – June 14–25, 1972 | publisher=National Oceanic and Atmospheric Administration (NOAA)| access-date=September 16, 2007|archive-url=https://web.archive.org/web/20150209162410/http://www.wpc.ncep.noaa.gov/tropical/rain/agnes1972.html|archive-date=February 9, 2015|url-status=live}}</ref> At Lock Haven, the river crested on June 23 at {{convert|31.3|ft|m}}, second only to the 1936 crest.{{sfn|Schuldenrein|Vento|1994|pp=4–5|loc=chapter 2, table 1}} The flood greatly damaged the paper mill and Piper Aircraft.<ref name="Yowell"/>

In 1992, federal, state, and local governments began construction of barriers to protect the city. The project included a levee of {{convert|36000|ft|m|sigfig=2}} and a [[flood wall]] of {{convert|1000|ft|m|sigfig=1}} along the [[Susquehanna River]] and Bald Eagle Creek, closure structures, [[retention basin]]s, a [[pumping station]], and some relocation of roads and buildings. Completed in 1995, the levee protected the city from high water in the year of the [[Blizzard of 1996]],<ref>{{cite web|title = Statewide Floods in Pennsylvania, January 1996 | publisher = United States Geological Survey | url = http://water.usgs.gov/wid/FS_103-96/FS_103-96.html | date = April 10, 1996 | access-date = November 30, 2009|archive-url=https://web.archive.org/web/20150514224339/http://water.usgs.gov/wid/FS_103-96/FS_103-96.html|archive-date=May 14, 2015|url-status=live}}</ref> and again 2004, when rainfall from the remnants of [[Hurricane Ivan]] threatened the city.<ref name="Yowell">{{cite journal | last = Yowell | first = Robert | title = Intergovernmental Success in Multi-Component Flood Mitigation: The Lock Haven Flood Protection Project Experience | journal = [[Journal of Contemporary Water Research and Education]] | issue = 129 | pages = 46–48 |date=March 2005 | url = http://www.ucowr.siu.edu/updates/130/11%20yowell.pdf | access-date = September 16, 2007|archive-url = https://web.archive.org/web/20070713141700/http://www.ucowr.siu.edu/updates/130/11%20yowell.pdf |archive-date = July 13, 2007}}</ref>