a. Within the UGB, creation of new open channels will not generally be allowed. Where allowed by the City Engineer, ditches shall be located along or adjacent to lot lines.

b. For reasons of maintenance and safety, bank slopes generally shall be 3H:1V or flatter unless otherwise required by the City Engineer.

c. The maximum allowable design velocity shall be seven (7) fps.

d. The minimum allowable design velocity shall be 2 fps. The installation of a concrete lined low-flow channel may be required to achieve minimum velocity.

e. Unless otherwise approved by the City Engineer, all piped discharges to open channels (existing or new) shall be mitered to match the channel side slope and include a reinforced concrete collar (6" minimum thickness) to prevent settlement or erosion of the pipe trench at the discharge location, and to protect the end of the pipe. The concrete collar shall extend from the channel bottom to the top of bank and will be reviewed on a case by case basis by the City Engineer. Grates shall be provided on all inlets or outlets 18" or larger unless otherwise specifically approved by the City Engineer , as well as at any locations required by the City Engineer to accommodate maintenance or mowing requirements. See Detail 3.62.