Complex sentence: In the 1960s the River Quaggy within Chinbrook Meadows and other parks was channelized into long straight concrete culverts to alleviate flooding and was closed off behind tall hedges and iron fences, this cut the park in two with the larger part to the east of the river.
Split into simpler sentences: In the 1960s the River Quaggy within Chinbrook Meadows and other parks was channelized into long straight concrete culverts to alleviate flooding. In Chinbrook Meadows the channelized river was closed off behind tall hedges and iron fences, this cut the park in two with the larger part to the east of the river.