Mr. Hickmann’s discussion of supply capacity, demand, storage capacities and well reliability is a confusing mix of topics that obscures important perspectives on the Bend’s water utility system. The following comments are directed towards clarifying the points raised. Hickmann’s responses if accurate raise serious questions as to whether the existing water utility, as well as the proposed SWIP plans, meets reliability standards.
2.1 Groundwater Well Capacity
Mr. Hickmann starts out by making an odd statement about the system’s groundwater capacity:
The City’s water master plan, developed by the engineering firm Optimatics, identified the reliable capacity of the City’s groundwater production facilities to be 9.0 MGD (Appendix E, Table 3, page 7). {A-1, B-6}
Comment: This number is incorrect. Mr. Hickmann confuses the water utility’s supply capacity with its storage capacities. The Optimatics Appendix E Table 3 details the calculation of the 9 mgd in wells that can be used as storage equivalents. Mr. Hickman’s response uses the “reliable supply” of 9 mgd in well capacity storage equivalence out of context, confusing the storage capacities analysis with the “firm” supply capacity of Bend’s water utility. Optimatics analyzes supply capacities in depth in multiple other sections of the 2011 report; well supply capacity is tabulated at 33.3 mgd, with a total of 32.2 mgd in service as of 2010 (Table 2.2, page 14 of Optimatics Final Master Plan Update).
If the City water utility has only 9 mgd of reliable well and surface water capacity is limited to a “firm planning” capacity of 7.4 mgd (Water Conservation and Management Plan, 2011), how is the City to provide a reliable supply to a city with a maximum daily demand of from 22 to 28 mgd (as detailed in Section 1)?
2.2 Reliability of Wells
Mr. Hickmann then goes on to acknowledge that the City has quite a lot of wells, and their machinery is unreliable:
The City currently has 20 operational wells at nine well sites, with a total installed pump capacity (which assumes all pumps are operational) of 30.5 mgd. However, the City cannot rely on all of this capacity from groundwater since well machinery has been known to fail without warning. …All of these aspects must be considered when evaluating the reliability or likelihood that a given number of wells will be operating at any given time. {A-1, B-6}
Comment. SWIP will not eliminate the need to correct these deficiencies or avoid this cost. Correcting well infrastructure deficiencies is not a cost of switching to a ground water only system. It is a cost of correcting deficiencies in the existing water utility so as to meet the “firm” supply capacity standard for municipal water systems. If the City’s priority is truly to provide reliable, safe water, as so often stated, the City should already have prioritized correction of well infrastructure deficiencies.
2.3 The City’s Ability to go to a Groundwater Only System
On the topic of the sufficiency of the City’s wells to meet the City’s needs – absent surface water – Mr. Hickmann goes on to make his feeling explicit:
The City does not currently have sufficient groundwater production facilities to reliably meet Bend’s water demand with only groundwater sources…{A-16}
The City would only be able to meet its peak water demand with groundwater exclusively if all of its wells remained operational and peak demand decreased. {A-2, B-6}
Comment. Mr. Hickmann uses questions about the reliability of wells along with misleading demand projections to infer that groundwater capacity is insufficient to meet demand. However, reliability, as distinguished from firm supply capacity, needs to be assured whether Bend has a dual source or a groundwater only water utility. Optimatics makes it clear that groundwater reliability questions must be addressed even if Bend continues to use a dual-source system. Since the current City delivery system is often turned off during high flow conditions in the creek due to excess turbidity in the water, if the City’s wells cannot meet demand reliability on their own then the utility will fail to meet demand. Reliability of the wells should therefore be assured.
When considering a groundwater-only system, the firm supply capacity standard requires redundancy in well capacity relative to demand. Consider that in 2011 Bend’s maximum daily demand was 22 mgd. The largest well the City has is the River Well #2 at 3.0 mgd capacity. The approach to firm supply capacity based on the largest well metric would call for maintaining a well capacity of 25.0 mgd. Given current well capacity of 32.2 mgd, one can conclude that current well capacity is above and beyond the firm supply capacity standard.
Due to the rapid drop in water demand in the last few years, and the continued expansion of the well system, Bend’s well capacity currently meets firm supply capacity standards for a groundwater only utility. The City could convert to a groundwater-only system immediately. That Mr. Hickmann does not agree with this point – as made by Mr. Bruckner – suggests that he is offering a novel interpretation of his own consulting reports.
