> industrial use. The narrow canals that still exist in Ohio and PA > and NJ that were formaly used for navigation are now used for > irrigation. The Locks are in Place buy only maintained for flood and > leval control > Some canals (the Llangollen and BCN are particular examples) survived as waterways because, once they existed, they were adapted for water supply or drainage; but there are extensive lengths (the Cotswold link is an example) where the channel has effectively disappeared because once trade went, it had no function. Lengths in built-up areas have been particularly vulnerable it's worth looking at what had to be done to restore the Huddersfield Narrow!
Sean
