Brewer Heineken is paying £160,000 to the Environment Agency after a pollution incident at a cider factory killed several thousand fish.
A container of ammonia-contaminated water was emptied to a surface-water drain at the firm's Bulmer's plant in Hereford.
The water then went into the Widemarsh Brook.
Heineken said it fully accepted the agency's findings and it had tightened up procedures.
It has also paid more than £12,000 to cover the agency's legal costs.
An agency spokesman said up to 3,000 fish were killed.
The money is being split between The Wye and Usk Foundation and the Yazor Widemarsh and Eign Brook restoration project.
Heineken accepted an enforcement undertaking, which is a civil sanction available to the agency as an alternative to prosecution.