Subject: Mirror Pond Rehabilitation
Date: Jan. 15, 1981
Location: Clark & Joyce, Inc.
Participants: Harold Baughman – PP & L
Ted Fies – Fish and Wildlife
Tom Gellner – City Engineer
John Hassick – City Planner
Vince Genna – Bend Park & Rec. Dist.
Richard Dornhelm – Winzler & Kelly
Maury Clark – Clark & Joyce, Inc.
John Joyce – Clark & Joyce, Inc.
The purpose of the meeting was to review the initial steps of the study for the Mirror Pond Rehabilitation project, which is being performed by Winzler & Kelly/ Clark & Joyce, Inc. It also provided an opportunity for the rep resented agencies/firms to give information to the engineers regarding concerns and restrictions that have to be addressed in the study.
John Joyce recommended that a citizens advisory committee be formed to provide additional local input into the study. The committee should not include technical representatives of agencies/firms, because they will be routinely included in the review process. Vince Genna suggested the Park District Board appoint 2 members and the City of Bend appoint 3 members. The committee size was agreed to, and Tom Gellner and Vince Genna will ask the City and Park District to appoint these members.
John Hassick suggested the need to coordinate with the irrigation districts because of the concern they may have on water flows and turbidity. The irrigation districts have about one domestic run a month during the winter. The run may last a few days, and turbidity would be a concern if the pond water level had been lower just prior to the run. Harold Baughman stated that during the irrigation season the water level can’t be lowered sigficantly, because the river flow is greater than the dam by-pass capacity. If an adequate diversion at the dam is achieved PP&L will consider lowering the water level for a definite time.
The sediment samples previously analyzed don’t show the location of the samples. Tom Gellner will check to determine if the locations were recorded.
Vince Genna advised that the Batell Institute has conducted a study on types of plants in the Deschutes River.
This study should be available from the Forest Service. According to Ted Fies, most of the plants are the same as those in reservoirs. John Joyce will check with Central Oregon Community College to determine if they have analyzed plant life in Mirror Pond. If COCC provides future analysis and services on this project, the cost may be included in the local share for the project.
Vince Genna has photographs taken from the air that show the sediment buildup in parts of Mirror Pond. These photos. are available for the engineer’s use and review.
The siltation process is going to continue because of the severe bank erosion upstream, according to Ted Fies. The high volume and changing levels of the river, caused by irrigation flows, result in severe bank erosion. There have been studies performed on this problem, and they are available at the Forest Service office. Tod pointed out that turbidity will be of greatest concern from October through March, because of down stream spawning. Mirror Pond is not considered significant as a spawning area, rather it is a rearing area. There will probably be some advantages as a fish habitat if the capacity of the pond is increased by removal of some of the sediment.
Adding islands with trees may present additional problems, because of the view restrictions. The Park District won’t encourage use of Mirror Pond for “in-water recreation.” Boating and canoeing will be encouraged when the water depth is increased. There should be a boat ramp provided for those activities. Harold Baughman recommended the ramp be located at a point whore the river is least apt to freeze, because there has been a need to rescue people from the thin ice on occasion.
Tho ice problem at Tumalo Bridge area was discussed. Ice forms .on tho bottom of the river (anchor ice), builds up and then breaks loose. This phenomenon has resulted in an ice jam at the bridge. Harold stated that they will open the by-pass gate at the dam to increase the velocity at the bridge, if they are aware of the problem soon enough. It is anticipated that the higher velocity will reduce the possibility of an ice jam. This problem should be considered if there are proposed changes to Mirror Pond as a result of the rehabilitation.
The City of Bend wip provide tho following data and information:
- Two copies of Mirror Pond X-Sections.
- Location of samples and basis for analysis.
- Data relative to types of plants, if available.
- Names of Citizens Advisory Committee.
- Copy of Storm drain maps.
Notes of Meeting by: John Joyce