C2 Dam Removal: If the dam is removed in Option C1, this is a possible outcome. After the dam is removed existing water levels drop and flow into original channel.
General Description: After partially dredging Mirror Pond and re-using the sediment on site, the dam is removed. When the dam is removed, the existing shallow waters retreat to the original channel. New lawn areas next to public park lands remain. The emergent zones and riparian shrub zones are re-graded to meet the new channel and require additional plantings for these zones.
Section 3(8) of the FPA defines “navigable waters.” In essence, navigable waters are those that are used or suitable for use for the transportation of persons or property in interstate or foreign commerce.
Section 3(8) “Navigable waters” means those parts of streams or other bodies of water over which Congress has jurisdiction under its authority to regulate commerce with foreign nations and among the several States, and which either in their natural or improved condition notwithstanding interruptions between the navigable parts of such streams or waters by falls, shallows, or rapids compelling land carriage, are used or suitable for use for the transportation of persons or property in interstate or foreign commerce, including therein all such interrupting falls, shallows, or rapids, together with such other parts of streams as shall have been authorized by Congress for improvement by the United States or shall have been recommended to Congress for such improvement after investigation under its authority;
In 2011, the Bend Hydro project generated 2,115 MWh or 2,115,000 KWh of electricity; that is almost enough power for 178 homes.* If Pacific Power had to purchase these 2,115,000 KWhs, the replacement cost is estimated to be around $77,000.
*In 2011, the average annual electricity consumption for a U.S. residential utility customer was 11,280 kWh, an average of 940 kilowatt-hours (kWh) per month. Oregon had an annual consumption of 11,892 kWh, an average of 991 kilowatt-hours (kWh) per month.
You won’t want to miss City Club’s February forum, where they tackle the Mirror Pond debate – but from a different point of view. What is physically possible? Come to their forum Feb. 21 and take part in the discussion.
Event: Mirror Mirror on the Pond What: City Club of Central Oregon Monthly Forum When: Thursday, February 21, 2013 from 11:30am-1:00pm Where: St. Charles Center for Health and Learning
Fee Schedule: Registration closes Tuesday, February 19, 2012, 5PM, buffet lunch is included Before registration deadline – $20 for members and first-time guests; $35 for nonmembers. Day of Forum-Walk-ins are welcomed for members and guests the day of the forum on a space-available basis for $35
Roger L. Raeburn, Manager Dam Safety
P.O. Box 3040
Portland, OR 97208
Re: Bend Hydro (Mirror Pond) Dam (B-99)- Inspection Summary
This dam was inspected on July 12, 2012. I performed the inspection with District 11 Watermaster Jeremy Giffin. You were there, as were Tom Becker and Nathan Higa from Pacific Corp. and provided very helpful dam history and safety information. The Water Resources Department conducts these routine inspections to identify safety, maintenance or operational issues that may affect dam integrity. Dams are assigned a hazard rating based on downstream hazard to people and property, not on the condition of the dam. Bend Hydro (Mirror Pond) dam is classified as a significant hazard dam. Significant hazard dams are inspected every 2-3 years.
The results of this inspection are illustrated and described in the following photos and text. This inspection includes recommendations to keep the dam safe
Results of Inspection:
The spillway is often the most important safety feature of a dam. The spillway is needle type structure, with multiple bays to wood stop and end timbers, and a more recent concrete cap.
A walkway constructed on top of the cap that allowed detailed inspection of top of the spillway section. The walkway was sound.
The rest of the spillway received visual inspection only. Some of the timbers show signs of significant decay. The concrete sections that support the bays, and their foundations near original, and a more thorough inspection at very low water would be prudent.
A leak through the spillway section was discovered by Watermaster Jeremy Giffin a couple of years ago. The leak was controlled by installation of sheet pi ling as shown above. The leak is an indicator that this part of the dam is showing its age, and in need of a thorough inspection to evaluate the base and the condition of the large timbers, and the overall needle structure.
The Emergency gate for this dam was just replaced with a new motor and controls. It was operated during the inspection (for a small part of its cycle, as the gate is not in the same condition as its control). The gate and control functioned well for this limited operation.
The gate structure is also old, but appears to be operational, and was opened for limited flow as described above. When closed, there is moderate leakage, mostly through gaps between the old timbers.
The concrete buttress wall forms the middle section of the dam. It is mostly the original section, so is also 100 years old. There are areas of minor to moderate spall, and some fairly minor cracking. Overall, the section appears sound. The area below the dam is well maintained grass, with no wet areas, and was maintained for easy inspections.
The location above shows the maximum deterioration seen in the buttressed wall section. Seepage loss was low, around one gallon a minute. This is not a concern at this time.
The powerhouse wall is also one of the dam sections. This was inspected from the inside, and is in the best condition of any of the dam sections, with no leaks or significant cracks.
Access to and security at the dam was very good. It is, fenced with appropriate signage. This is a run of the river reservoir, and there are no signs of erosion around the dam site.
Continue with good maintenance and operations, including security, vegetation control, and security.
Evaluate Deschutes River flow, and accompany me on an inspection of the base of the spillway structure at very low water. I will coordinate with you and Watermaster Jeremy Giffin on the timing of such an inspection.
We use a standard inspection form for all dams, and a copy of the field inspection sheet for this dam is attached. The next regular inspection is planned for 2015. Thanks for sending me the drawings of the dam, and please let me know if you have any questions about this inspection.
Virginia “Ginny” was destined to live life as she saw it, mostly in interesting ways that we envied. She was a strong-willed girl who was fortunate to have parents that loved, and encouraged her to find her own path.
Born May 25 1918, in Muskogee, Oklahoma, to Greek and Lillian Beaston, they moved to Bend, Oregon soon after, where she was raised by her mother, and stepfather, Bill Anderson. She was athletic, and loved the game of tennis. After graduation from Bend High, she attended finishing school in Seattle, before graduating from Willamette University in Salem, Oregon. Ginny’s beauty, and outgoing personality, were instrumental in her being elected Queen of the Bend Water Pageant in 1935.
She met and married the love of her life, Jake Wolfe in 1945. Jake was an Iowa boy, fresh home from the war. During the course of their 51 years together, they raised three children, Kim, Scott, and Marcia, who were with her at her time of passing in La Quinta, California, June 5, 2012. At one time she ran the Keystone Trailer park, helped start WB Anderson Trailer & Marine Sales, and was a strong supporter of Jake’s decision to found The Bank of the Cascades. Jake passed in 2001. He, equally supported her desire to open The Copper Room fine dining restaurant and bar, loving the experience and its patrons, becoming “Ginny” to all. They traveled the world in their later years and never stopped having fun while enjoying the spectacle of life and nature.
Her passing was a beautiful time, with her children at her side, holding her hand, with the strains of Amazing Grace in the background. Her dog “Woof” gave her one last kiss, and she slipped away.
The issue of fish passage at Mirror Pond has come up again recently…in short, I do not think that a roughened channel or natural type fishway would work at this site. I am not familiar with the site, so I wouldn’t want to say 100%, but typically these types of solutions only work in cases when the obstruction is less than 5 or 6 feet tall. In the case of Mirror Pond Dam, my information says its around 20 feet tall. Generally at such a large obstruction there is not enough space downstream to effectively provide passage with a roughened channel or another type of “natural” solution. For example, NMFS guidelines for a roughened channel is max 150 feet long, and maximum 6% gradient. That means that even at these maximums, which may not provide very good fish passage, the maximum “height” the roughened channel could be is 9 feet. Couple that with the natural channel gradient in the stream, which on the Deschutes is likely 1-3% (which gives you a drop of 1.5 to 4.5 feet over 150’), then the roughened channel would only be overcoming 4.5 to 7.5 feet of the 20 foot barrier. In addition, typically roughened channels become very unstable at heights above 5 or 6 feet.
If and when stakeholders and interested parties go down the road of developing and implementing fish passage at Mirror Pond, we will have all options on the table, and will investigate all possibilities for passage. The ultimate goal will be to develop a project that meets the needs of the native migratory fish on site, and meets the needs of all the stakeholders at the site.
I appreciate your participation, interest, and questions in this matter, and do feel free to let me know if you have any other questions.
Thank you, and take care.
ODFW-Assistant Fish Passage Coordinator