QBD 29 July 1993. In October 1989 the first respondent (W) granted planning permission to the second respondent (B) for the extraction of coal and clay from land in September 1990. W approved a reserved matters application by B relating to the possible diversion of the River Calder pursuant to permission granted in 1985. In July 1991 planning permission was granted for the extraction of minerals from a site near the river. The legality of the decisions were challenged in three applications. The first challenged the 1989 permission on the grounds that the alterations to the application were so substantial that a new application was required. This was dismissed on the grounds that W were entitled to exercise their discretion to treat the alterations as amendments. The second challenged the 1990 approval of the river diversion on the grounds that W had acted ultra vires and unreasonably. This was dismissed on the grounds that W had not acted unreasonably in treating the application as o