Lake Level – DLWID Perspective

By now you should be aware that changes to the summer time lake level are once again on the DLWID Board agenda.  We feel it is important to understand the Districts perspective on this matter and we are fortunate that our Lake Manager wrote extensively on the subject in the Managers Report.  It is unusual for us to post such a large excerpt; normally we would simply provide a link.  In order for there to be no misunderstanding or re-interpretation we included the text from the report pertaining to lake level in its entirety. We do feel compelled to note that in the fact checks and clarification section the report mentions some inaccurate statements made by a blog.  This was not as we have not yet reported on the water rights issue.  We’re still checking our facts; we do make mistakes but not this time.

Except from Devils Lake Manager Report 2010-06-03

Lake Level: Potential operational changes to the dam are being discussed at this meeting as additional information about lake level has been presented that represent that much less recreational water use benefit (e.g. deeper water at docks and shorelines) may be apparent at 9.53’ than assumed. Meanwhile many of the 22 property owners, that petitioned the District in 2009 for a lake level of 9.0 feet may be being impacted without substantial benefit to other lake users as previously assumed. Copies of that petition and subsequent flier distributed by an equally concerned homeowner opposing any change in the water level are available as reference items on our website. Working through these seemingly conflicting interests is thus to be addressed at the District’s next meeting. Public input will be afforded, but please limit your input to a concise statement at the beginning of the process, reserving additional comments should you have them for the end of the meeting.

Current Status: Currently (2010-05-27) the lake is sitting at 9.5’. The latest lake level measurements are available on our Water Quality page of the website ( Currently one section of the dam is open again at this time as rains have brought the lake up and fish passage issues are at least being attempted to be mitigated for by pulsing and/or section removal. This period of pulsing and/or whole section release will end after May 31st. The utilization of the dam from June through October, is thus open for consideration.

Current Considerations: It had been voiced in March 2010 meeting that if the dam was not installed in April, many properties would not have access to the lake for additional months. A motion was made to install the dam allowing for the new lake contractor the flexibility to allow for fish passage by means of leaving one section out of the dam providing the lake level could be maintained between 9.5’ and 9.3’ through June 1, 2010. At the time of the meeting (March 4, 2010) the lake level was 9.0’ above MSL. It was stated by a member of the audience that at this lake level many properties would not have access to the lake. Data were subsequently gathered by two of the District’s board members to investigate the potential impact on users at this same lake level of 9.0’. This presentation was made at the April 4, 2010 meeting and is available online at our website on the Project page under Lake Level (Director Presentation 2010-04-01 UPDATED). Some of the conclusions of that presentation were that nearly all of the properties surveyed the depth of the water when the lake was at 9.0’ was sufficient for drafting a typical pleasure craft. Where draft was insufficient at the far end of the canal on Thompson Creek, the addition of 6” of water to 9.53’ would have marginal benefit. For a complete review please revisit the slideshow from our website. Additionally a comprehensive review of this issue of the 2009 review is also available online (Staff Presentation 2009-04-01 ). What is presented below is new or additional information in no particular order that may be pertinent to the board discussion and decision on this issue along with some summary issues from previous meetings.

Water Rights: Rock Creek & Siletz POD: Irrigation of the golf course in our watershed came before City Council Monday 2010-05-24 for consideration. This is a proposal between the Confederated Tribes of Siletz Indians (CTSI) and the City of Lincoln City for selling water from the City’s existing water right on Rock Creek, a tributary of Devils Lake for irrigation of the Chinook Winds Golf Resort. This water right is held by the city, and as a municipal right it a permanent right, originally obtained by the town of Oceanlake. In fact, an existing, but unused pipe runs under Devils Lake that once served this community. As many will remember in 2006, the Devils Lake Water Improvement District, partnered with the Salmon Drift Creek Watershed Council, USFWS, ODFW and the City to alter a dam at the current Point of Diversion (Approximately River Mile 3.2) for fish passage. The current proposal would be to add a second Point of Diversion (POD) on this certificated municipal water right. City Council voted unanimously to approve this agreement.

This agreement would have to go through Water Resources as explained in Mr. Hawker’s email and attachments provided on our website. As we have discussed there are many benefits to irrigating with water already loaded with nutrients, as it would greatly reduce the amount of fertilizer added to the watershed. Chlorinated tap water is currently used which must be infused with N-P-K to grow grass. This would have the effect of reducing the loading on the lake, and in fact be a nutrient reduction strategy for the lake water itself. There are of course other considerations including water extraction during the summer months and the potential of other types of runoff  (pesticides/fungicides) should the water not be used conservatively. These however already exist under the current state of irrigation. Pesticide and fungicide use may in fact be reduced as irrigation with chlorinated water ceases. Reducing the stress on the grass which comes with chlorinated irrigation reduces the plant’s susceptibility to infestation by fungus and pests. I would expect a formidable presentation by the Tribe and the City at some time which would allow for the mindful consideration of this existing water right transfer. While I reserve the right to further consider this agreement, it is certainly a proposal with merit considering the current state of affairs with tap water and fertilizers being sprayed on the golf course. Other provision in the potential agreement would require the City and the Tribe to meet regularly to seek alternative water sources, specifically re-use assumingly of the City WWTP effluent.

As a note 0.5 CFS is being negotiated with provisions that the previous applications by the Tribe for Neotsu Creek be withdrawn which were near or above the same amount as I recall. This is about an acre foot a day which on a 680 acre lake would be 0.017 inches a day * 30 days * 3 months for about 1.5 inches a summer season if my calculations are correct. The current usage of 12 million gallons of tap water would be about 0.7 inches off the lake surface for the year. This is at the current footprint of the golf course, but that would increase potentially as I understand. Previously the Tribe has stated that they would need 75 AF of water for the full build out of the golf course which is about double (24 million gallons) what they are buying today which would convert to about 1.3 inches of lake level. This is what was being talked about (I specifically remember 1 and 5/16” = 1.3125” being considered) over a year ago so the proposals seem to remain in line with the previous applications for well water and or those currently on hold for other streams in the watershed.

The Tribal Council must also approve of this agreement for it to be passed on to Water Resources who would have the final say. If the District would like to comment of this Point of Diversion, a formal request should be made through Water Resources. The District might also request from the City and the Tribe a presentation of their proposal and an opportunity to ask question or seek clarification prior to submitting comments. This is what Mr. Hawker in his email suggested he would like to have the opportunity to do.

Both of these steps (Reservation of opportunity to comment and a request for a presentation) are recommended by staff to pursue as a separate manner.

Relating to the issue of lake level, the District should bear in mind that potentially approximately 75 AF of lake water would be extracted over the course of a summer. This would not necessarily drop the lake by the 1.5” that this calculates to be as the maximum water diversion being considered of 0.5 CFS is only a fraction of the volume of water flowing in Rock Creek at that time of year, and the 75 AF extraction would come over the course of the summer. Hydrology is complex, and only in the extreme bathtub model of a watershed where the tub is filled and then water an amount of water such as 1.5” of the level be drained would that be measureable. None-the-less, water extraction may have some effect on the ultimate level of the lake.

Fact Checks and Clarification: Recently many inaccurate statements and comments have circulated which demand refuting or clarification. A blog recently posted the Siletz Tribe would give up its water use of Rock Creek should the agreement go through. Such use does not, nor has not existed. Supplemental irrigation has been with municipal water purchased from the City of Lincoln City. A suggestion of the lake being used as storage is inaccurate. The lake has a residence time based on its volume of 0.15 years, thus only a month or so of the average total annual flux of water would refill the lake. While arguably much of the water comes in winter, the 0.5 CFS water right also necessarily would have to be available in the tributary (e.g. Rock Creek) at the time of water extraction for the water right be executable. Basically should that creek dry up, the City would not have the water to sell, and would be unable to provide the water to the Siletz Tribe A suggestion that monitoring this extraction would be impossible or that it would be likely be in excess of the agreement are completely unfounded. Not only would it be unwise to overwater the golf course, a self regulating mechanism, the City has an invested stake in assuring that the water that they have the legal right to sell is properly tabulated correctly. Oregon Department of Water Resources would also require defensible documentation of such water use. Another statement recently circulated is that this agreement would not serve the lake in anyway. While this may be certainly the author’s and others opinion, it is scientifically clear that fertilizer reductions can be seen by using nutrient rich water as opposed to basically sterile tap water when growing plants. It is also clear that nutrients in that water could then be sequestered in plants and soils upland as opposed to their current location in the lake or its sediment where they feed cyanobacteria and potentially exotic weeds. Fair evaluation of the potential nutrient abatement and nutrient sequestration should be given merit when considering the larger District goals of water quality, not just water quantity as is being discussed currently.

Lastly, it should be clear that while the District may have a right to comment on this water right as would any other potentially affected entity or individual, the water right on Rock Creek already exists, and the City can at their choosing fully exercise the water right of a full 1.5 CFS at its current Point of Diversion. The City’s right is senior to the District’s recreational water use right, and thus it is the District’s right that would be curtailed should water needs be in conflict. Irrigation from this existing POD would seemingly also require supplemental nutrient enrichment, continuing a measureable influx of N-P-K as fertilizer on to the watershed. Additionally should the water transfer not occur, the Tribe currently has existing water rights for wells in the watershed and has an application on hold for Neotsu Creek. Should these rights be used to fulfill the some 75 AF of water currently necessary for irrigation, supplemental fertilization would likely also be required as it does currently under the chlorinated water irrigation regime.

Septics Systems: We are on the verge of a comprehensive review of septic systems in the watershed. Work conducted by Seth has revealed that 665 tanks are in the watershed with about 267 set on lake front properties. Roughly 1/3 of all of these systems have no record at all, suggesting that they were placed in the ground prior to 1974 when regulation became more stringent. Development for much of our area began closet to the lake and work outward as many of the earliest settlers chose to have summer camps on the lake. These camps, now summer homes, vacation rental dwellings, and full time residences still heavily rely on septic tanks and drain fields for domestic waste treatment. Key to the functionality then is the maintenance of all these systems currently being address under the proposed ordinance.

What will become more clear through these inspection is how and if many of these systems are functioning or to what extent. What we know now however is that the density in which they currently exist greatly exceeded what EPA recommends, and that many of the low lying properties (particularly on Loop Drive near Sand Point and in areas of Neotsu) have systems that inherently are either near, at, or potentially below the water table. Aggravating that at, or near saturation condition then is when the lake level is artificially held at 9.53’ during the summer months when the lake level would otherwise be lower, and at a time when homes are occupied at their maximum. It is fairly clear that as a consequence of living on a lakeshore, the water table may sit only feet or inches below the surface at most anytime of the year. This may significantly impact the efficiency of waste water treatment in such soil environments. Firstly when tanks sit in groundwater, they tend to rust or corrode more quickly and may thus leak. Secondarily when drainfields are saturated, they fail to function properly as bacteria in the soils must digest the wastes anaerobically, a process 30-50 times less efficient then under properly drained, aerobic conditions. A few of the effects then that pervade are the risk of poorly treated wastewater entering the lake at a time of peak recreational use and the release of nutrients which feed cyanobacteria blooms which also occur in the summer months.

Boating Access: This as I understand continues to be the number one concern raised by individuals. While ideally each parcel on Devils Lake and the canals that have been dredged in the watershed in past years would have ample water draft for most any type of vessel, this just isn’t a practical matter. Lakeshores are inherently diverse as wind and wave energy over the centuries (and even years with the advent of wake boards) mold the shape of the shoreline and the lake bathymetry. To attempt to assure all lake and canal front properties had sufficient draft for motorized and wind powered water craft would require continual dredging and/or a water level that greatly exceeds the legal height the District can hold the water at, 9.53’ above MSL. A means then to address public access to the lake then can and should be met with public boat accesses, for which three improved and two lesser improved accesses exist. The improved launches are at Regatta Grounds, Holmes Road Park, and East Devils Lake State Park, which allow generally for day-use parking and launching and retrieving of pleasure boats and vessels of many sizes and shapes. Other options for public access may include use of private and/or commercial launches or moorages. These are beyond the scope of the District currently, but are available to at least some extent. Should insufficient moorages exist, the District or other entity could seek to develop such moorages which would facilitate draft requirements for vessels not otherwise able to be anchored along 100% of a shoreline such as the case is with Devils Lake.

Campground: A tour of the campground during Thursday’s (May 27th) sampling  showed many sites heavily inundated with water. Typically when the lake is held at 9.53’ after a rain the low lying campsites have continued to be inundated, but will dry out to a fair degree with consistently drier weather. Saturation of the campground has been an ongoing problem, particularly at the beginning of the summer season, dating back at least to when the dam was repaired. This is at the beginning of the Memorial Day Weekend, which certainly has a negative impact to visitors to our area and to those that might choose elsewhere to spend their holidays and vacation in the future. As Lincoln City is inextricably connected to tourism, this impact can not be overlooked.

Cyanobacteria Blooms: It has been suggested that any decrease in the lake level would increase the intensity of cyanobacteria blooms. There may be some merit to that claim, but there may be an equal number of considerations to argue against it. Case in Point: While it is true the temperature is related to blooms, the reduced depth that could facilitate heating during the day, similarly can increase radiational cooling at night potentially negating the effect. This would be particularly important at the end of bloom as temperature begin to cool, potentially providing a much quicker demise to the bloom than if additional water was in storage. Also should a larger volume of water be created by impoundment, the affect of cold water entering from the various tributaries would have a proportionately reduced effect on cooling. Thus if a bloom was active and a rain event brought cold water into the lake, the relative affective cooling would be diminished by a higher lake level, potentially allowing the bloom to sustain for longer.

Dilution has also been evoked as cause for holding additional water, however the water in the lake is largely homogenous in regards to nutrients, and thus the stacking of water at the D River by a dam is simply storing the same quality of water and is not like the dilution with distilled water. The glut of nutrients in the sediment are at some state of balance with the water above, these nutrients are largely free to migrate into the water column and do so based on the chemical properties of the nutrients and the water which mobilize them. Wetlands also play roles in regulating cyanobacteria blooms which under a reservoir hydrology are negatively impacted. Wetlands give rise to plant materials that once dead and degrading can produce hydrogen peroxide, a powerful oxidant that kill cyanobacteria. This is the same process as when barley straw is use to treat cyanobacteria, and is only beginning to be understood scientifically. Functional wetlands also are a primary nutrient sink for nitrogen in particular. While additionally lake level might seemingly provide a growth in wetted area, the unnaturally hydrology does not necessarily sustain the plant population. The most important consideration may be that while some affects may actually occur given the extreme variability of cyanobacteria blooms, teasing out the causative effects would be very difficult. The larger influence on cyanobacteria bloom development such as nutrients in the lake and the watershed are likely to be much more significant than the plus or minus associated with a moderate change in lake level.

Erosion: Reports of ongoing erosion of the shoreline, assumingly attributable to the saturation of the soils and the increase wave energy associated with higher lake levels during the summer months, have been received. The District is seeking to evaluate these reports though an independent erosion study it is developing a RFP for currently. What can be said though is that impoundments and reservoir conditions as have been established on Devils Lake generally can have a significant impact on plant distribution, which is the basis of a stabilized shoreline. Riparian species have uniquely evolved to protect a shoreline from the impact of flowing water. These and wetland species (capable of greater saturation) have evolved under flow regimes repeated for millennia where peak rain follows peak water heights, followed by drier times with increase sunlight where root and shoot growth is most substantial. These wetland and riparian species have difficulty competing on shorelines without these periodic wet and dry conditions, and thus may be supplanted by more aquatic species and/or upland species as the case may be. Aquatic species though lack the root structures to provide for stabilized shorelines and thus are not able to hold shorelines. Confounding in the Devils Lake basin then are the presence of Chinese Grass Carp which make the establishment of even these aquatic species an impracticality. Upland plants which might try to move into areas made drier by hydrology intervention (e.g. draining wetlands, etc.) are unable to withstand the pressures of inundation should they return, limiting the upland plants expansion. These regions where plant redistribution occurs are vulnerable to the subsequent change in hydrology when a reservoir is drained or flooded. What is known in these reservoir systems is that the areas become devoid of much of the plant life where vital communities of riparian and wetland species would otherwise grow. This lack of vegetation is known to lead to erosion.

Another element of erosive forces may be enhanced by higher lake levels, that of increase wave action and wave battering on more upland areas as a result of additional water level. This is a primary investigative item for the erosion study. What can be gleaned prior to such a study is that water being the universal solvent will seek to dissolve and erode rock upon which it sits or surrounds. Increasing the surface area of that interaction inherently increases the dissolution and erosive capacity on the rocks or in this case the shoreline.

Fixed Docks: An issue has been raised with fixed docks and how they have only one optimal height for entering and exiting a boat. While many of the recently installed fixed height docks installed by at least one local contractor have an average height of 10.0’, this is only a fraction, less than 1/20th as mentioned in a past meeting by that same contractor, of the docks on the lake. Particularly, other fixed docks certainly might have been built at a time and to a height prior to when the lake began being impounded (1998). The lake level would at least reach approximately 8.3’ in the decades prior (this according to the notably scant, but at least consistent reporting of one founding and long-term member of PADL and former District board member, Al Rice (see Figure 1)). Many docks built before impoundment would assumingly have been built to the height of the water generally seen during the peak recreational use of the summer months. Effectively these docks might be swamped by conditions in the winter and/or during times of summer time impoundment to 9.53’ or historically even higher. What then can be concluded is no lake level is going to serve all docks equally. There are ways to mitigate for such variability, notable the use of ladders for access to vessels and/or the use of or modification to a floating dock which can guarantee a fixed height above the water.

SOS: The District has been through investment in staff and through direct funding been encouraging and facilitating the planting of native plants on the shoreline. These native plants are typically suited to the periodic inundation normally present on a shoreline. This occurs only during the natural hydrology and is negatively impacted by reservoir conditions as explained in the section above on erosion.

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Filed under DLWID, Lake Level, Lakeside, Rulings

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