Sutton and Mole Valley lines Sutton and Mole Valley lines The Sutton and Mole Valley lines were constructed between 1847 and 1868 by the London, Brighton and South Coast Railway, the London and South Western Railway and the LBSCR-sponsored Horsham, Dorking and Leatherhead Railway. Services include commuter services in South London, Surrey and West Sussex operated by Southern, usually from London Victoria to Horsham via Sutton and Dorking. Some Southern services in peak hours from call at and diverge at Leatherhead and serve Effingham Junction and Guildford via the New Guildford Line. The South Western Railway services are operated by Class 455/7s, 455/8s and 455/9s.
River Mole Dorking drains an area of , of which approximately 60% is on Wealden Clay or Atherfield Clay, 20% is on Tunbridge Wells Sand and 20% is on greensand. Brickearth deposits are common in the valley around Betchworth and east of Dorking. The upper Mole catchment is dominated by a single broad terrace, which runs continuously from the entry to the Mole Gap as far south as Tilgate Forest. Above Meath Green (near Horley), the terrace corresponds to the flood plain of the river, however from this point downstream to Brockham, the river cuts a narrow trench no more than wide.