The Wych Brook rises (as the "Red Brook") at Fenn's Moss on the Wrexham County Borough / Shropshire border, and flows northward and westward through a steep-sided, wooded valley to Threapwood, being joined by several smaller streams such as the Grindley Brook, which rises near the village of the same name, and the Iscoyd Brook. Near the community of Willington Worthenbury it is joined by the Emral Brook, and runs northward to the Dee (as the "Worthenbury Brook") near Shocklach.[1] The Emral Brook itself rises near Penley and is joined by a number of tributary streams which drain the central part of Maelor Saesneg.
The middle section of the river valley, which has eroded deeply into an underlying glacial drift of boulder clay, sands and gravels, is the narrowest and deepest, particularly between Dymock's Mill and Lower Wych.[2] The river landscape is characterised by ancient mixed ash woodland, unintensively-farmed lowland pasture and rush pasture. The English side of the valley is designated as an Area of Special County Value.[3]
Typical landscape of the Wych Brook valley: the foreground is in England and the rising ground in the distance in Wales.
The Wych Brook was formerly known as the River Elfe or Elf. The origin of the name "Elfe" is in this case unknown, though the name "Wych" is thought to derive from saline springs in the area. There were formerly a number of natural salt springs or 'brine pits' near the river bank at Higher Wych and Lower Wych, which from medieval times were used as a water source for commercial salt production.[4] It has been speculated that the river name Elfe is based on the Welsh language root hal-, halen, "salt".[4]
