Loading...
HomeMy WebLinkAbout5 - Motion recommending a Management Option for Thunderbird Lake at Burke Park CITYOFBOULDER WATER RESOURCES ADVISORY BOARD AGENDA ITEM MEETING DATE: January 12, 2009 AGENDA TITLE: Public Hearing and Consideration of a Motion Recommending a Management Option for Thunderbird Lake at Burke Park PRESENTERS: Ned Williams, Director of Public Works for Utilities Alice Guthrie, Interim Recreation Superintendent Matt Claussen, Urban Resource Manager Joy Master, Conservation Ecologist EXECUTIVE SUM117ARY: The purpose of this memo is to provide the Water Resources Advisory Board (WRAB) with additional information on potential management options for Thunderbird Lake as discussed at the December 15, 2008 meeting. The WRAB is asked to make a recommendation to the City Council on a management option for the lake. Along with the Parks and Recreation Advisory Board's (PRAB) recommendation and public input, the WRAB's recommendation will he provided to City Council at a future meeting, tentatively scheduled for February 3, 2009. The key elements identified for Thunderbird Lake are the changing hydrology of the area and the capital and ongoing funds that will be required for ongoing management of the lake. Staff and consultants have been investigating actions to manage the lake including evaluating ways to add water. A comprehensive evaluation of each considered option can be found in Attachment A and was provided to the WRAB on December 15. Recognizing that a plan of action had not yet been determined for Thunderbird Lake, $200,000 for potential capital improvements was approved in the 2009 Capital Improvement Program (CIP) budget. When a management option is identified, Parks and Recreation Department staff will determine the ongoing maintenance costs of the recommended option and discuss funding options, include re-prioritizing current work tasks or identifying trade-offs or reductions in levels of service level. In 2008, approximately $115,000 has been spent on consultants and management actions, not including staff time. These expenses were funded by a supplemental budget request. To assist in the decision-making process, staff has included a matrix of benefits and impacts for each option (Attachment A-1) and has provided additional information on cost estimates for each option (Attachment B). These documents were provided to the WRAB in the December 15, AGENDA ITEM # 5 PAGE 1 2448 meeting packet and are not included with this memo. Responses to questions raised by WRAB members at the December 15 meeting are included in Attachment C. The WRAB is asked to recommend a management strategy, given the City Council filters of economic, environmental and social sustainability. STAFF RECOMII~ENDATION: In consideration of the goals of the Parks and Recreation Department's master plan and the city and department's current fiscal situation, staff recornrnends Option B, Adaptive Management (No Supplemental Water). If this option is selected, staff will develop an appropriate adaptive management plan for the lake. This recommendation aligns with the Parks and Recreation 1Vlaster Plan goal to "Maintain and protect our parks and recreation facilities and programs." With this option, staff will dedicate the resources needed to manage the lake and surrounding area in the manner established in 2448. This involves continuing to address neighbor concerns such as maintaining the water circulation unit, adding microbes to control algae, removing duckweed, maintaining the view corridors, monitoring the water level, monitoring for Culex mosquitoes and applying Bti when present. As part of the Adaptive Management approach, staff will monitor and make adjustments based on the goals established in the management plan. A description of the Adaptive 1Vlanage~nent process can be found in Attachment A-2 and a diagram of the process is also included in Attachment A-3. These documents were provided to the WRAB in December. Additionally, the existing the drain would be maintained, so water would flow into the lake when the groundwater is adequate. Staff does not recommend adding potable water as this would set a precedent for using potable water in other lakes and ponds, such as Viele Lake. If the WRAB does not support the staff recommendation and recommends adding supplemental water to the lake, staff recommends Option D, Potable Water (multiple fills per year), for a period of three years to achieve water quality goals. Staff would manage the lake and surrounding area in the manner established in 2448 (see above), and add potable water as necessary to maintain acceptable water quality. This would be the least costly way to add water to the lake in an effort to achieve the goal of having a visible lake with minimal odors. All expenses (resources and staff time) would be tracked. Ongoing maintenance costs would be calculated and budgeted in the Parks and Planning Division's operating budget and would result in internal re-prioritizations and reallocations. The three-year time frame coincides with the renewal of the necessary wetland permit. At the end of the three-year period, staff would return to the PRAB (and potentially the WRAB and City Council) to review the management information and discuss the continued addition of potable water. If potable water is used, it should only be used at Thunderbird Lake and with the following conditions: • A water budget (separate from the existing parks irrigation budget) is established and followed; • The cost of water would be charged according to Block Rates; and • The availability of water will be subject to the city's drought plan. AGENDA ITEM # 5 PAGE 2 KEY ISSUE IDENTIFICATION: Balancing the priorities of the community as identified in the Parks and Recreation Department's master plan with the expressed interest of the neighbors, the feasibility of adding «~ater to the lake and the financial resources necessary for ongoing management of the lake are the key issues associated with this project. COMMUNITY SUSTAINABILITY ASSESSMENTS AND IMPACTS: • Economic: Thunderbird Lake is located in a neighbourhood park that does not host community wide events. As such, its contribution to overall economic vitality is minimal. Some nearby residents have expressed concern that property values may decline if the lake is not returned to its former condition. • Environmental: According to biologists, the lake in its current condition is a healthy, functional ecosystem providing wetlands and wildlife habitat. With the changes in hydrology in the area, it will be difficult to guarantee sustained water levels in the lake over time. • Social: Community members have expressed diverse perspectives on the condition of the lake. Some residents believe that wetlands and wildlife habitat provide important learning opportunities for residents and nearby school children. Other residents have indicated that the park and lake are important to them as a place to be outdoors and recreate. These residents value a lake with snore water that contains fish and has little vegetation on the surface or the banks. OTHER IMPACTS: • Fiscal: Depending on the method of water delivery, the costs to add water to Thunderbird Lake on an ongoing basis are substantial and range from $77,000 to $766,500. The estimated initial costs for the option that adds potable water multiple tunes per year range from $89,000 - $158,500. The estimated costs to manage the lake without adding water range from $10,500 to $52,500, depending on the level of management. Additional amenities constructed around the lake are not included in this cost estimate. • Stafftirne: All of the management options presented, with the exception of "No Action," will require additional staff time. Ongoing maintenance costs will be calculated and budgeted in the Parks and Planning Division's operating budget and will result in internal re-prioritizations and reallocations such as decreasing park maintenance, urban Integrated Pest Management (IPM), prairie dog management and,~or seasonal staffing. PUBLIC FEEDBACK: Since 2007, some members of the community have contacted the PRAB and City Council requesting that the water level of the lake be returned to previous levels and that it be managed to achieve its historic aesthetic condition. Department staff held two neighborhood meetings (September 27, 2007 and February 21, 2008) to discuss the changes in the lake and to gather community input on potential management options. Some neighbors expressed a desire to have the lake filled with water and several suggestions were made as to how that might be achieved. Staff included the suggestions in the methods that were evaluated. AGENDA ITEM # 5 PAGE 3 Community members have been updated monthly since September 2007 on the work of the consultants and management actions taken at the lake. The updates «~ere emailed and mailed to community members and posted on the department's web site at http:;`/www.bouldercolorado.~ov;`index.php?option=com content&task=view&id=8221&Itemid =3171. In addition, staff has been in regular contact with interested residents. BOARD AND COMMISSION FEEDBACK: Background information on the history of Thunderbird Lake was provided to the PRAB in a February 25, 2008 memo that can be found at http:,~`/www.bouldercolorado.goviindex.phn?option=com content&task=view&id=4554&Itemid =1889. At that meeting, the PRAB recommended that staff conduct additional research and return to the PRAB with the results. At the September 22, 2008 public hearing, the PRAB voted 5-2 to approve Option B, Adaptive Management - No Supplemental Water. BACKGROUND: In 2001 and 2002 the city of Boulder began experiencing drought conditions and the water level at Thunderbird Lake began to drop. In 2007, members of the community contacted the PRAB and City Council requesting that the water level of the lake be increased from current levels and that it be managed to achieve better aesthetic condition such as a clear, visible lake with less vegetation on the surface and around the shore. In the fall of 2007, staff hired Biohabitats, Inc. to prepare a report that would address the history of the lake, current conditions and four potential management options. This information was provided to the public and to the PRAB as part of the February 25, 2008 memo (http://www.bouldercolorado. gov/index. php?option=com content&task=view&id=45 54&Itemid =1889#feb25). The Biohabitats, Inc. report, Potential Future Management ~ption,s for Thunderbird Lake, included an assessment of water quality, water quantity, preliminary cost estimates and next steps. Staff provided cost estimates for initial capital costs and ongoing management costs for each option and noted that there was uncertainty regarding whether water rights would be needed to pursue certain options, among other unknown factors. The PRAB requested that staff conduct additional research to evaluate the management options, including the feasibility and cost of supplemental sources of water for Thunderbird Lake. Due to the complexity of this issue, department staff consulted with other city staff (Water Utilities and Planning and Development Services) as well as experts in several disciplines -geomorphology, hydrology, wetland ecology, engineering, water rights and Colorado water law. Staff again hired Biohabitats, Inc. to assist with the request and to prepare a report that further evaluated the new information. Based on the original options presented at the February 25, 2008 PRAB meeting and additional community input, further analysis by staff and experts identified costs and constraints and AGENDA ITEM # 5 PAGE 4 resulted in an expanded menu of management options for consideration. Staff researched eight options for managing the lake, including methods for adding supplemental water, as well as options for not adding water. Staffreturned to the PRAB at a public hearing on September 22, 2048 with this additional information including the Biohabitats Inc. Memorandum (September 17, 2008) that explained in detail the lake elevation, outflot~~, timing of water availability, nutrient loading, design and construction costs and timefrarne and briefly addressed the benefits or limitations and next steps. Many technical reports were provided by the experts to inform this multifaceted issue. These reports, the PRAB memo and supporting documentation may be found at: http:,`/www.bouldercolorado.gov,'index.phn?option=com content&task=view&id=4554&Itemid =1889. CURRENT MANAGEMENT: While pursuing additional information for long-term management strategies (discussed above), since May 2008 staff has conducted the following management activities at Thunderbird Lake: • Maintained the water circulation unit • Added microbes to the lake to control algae • Removed duckweed • Maintained the view corridors for views of the lake • Monitored the water level in the lake • Monitored water quality • Added 525,000 gallons of potable water • Monitored for Culex mosquitoes and applied Bti when present The results of the ongoing monitoring indicated that the existing the drain was not going to provide enough water to fill the lake and a decision was made to add approximately 1.5 acre feet of potable water to Thunderbird Lake. A wetland permit was obtained for adding water to the lake and removing vegetation along the shore of the lake that would become inundated and decay, causing potential odor problems. Beginning on July 9, 525,004 gallons of water were added to the lake over five days, equaling 12 inches in depth. Since the addition of water, staff has monitored the water levels and evaporation rates. By August 6, 6.72 inches, or 56 percent, of the additional water had dissipated. As of November 12, the v~~ater that was added had decreased an additiona14.32 inches for a total of a 92 percent loss. As of December 3, the water level has further decreased such that the lake has lost 100 percent of the water that was added in July. Staff is working with engineering consultants and construction staff to lower the existing outlet fiom the lake, at a cost of approximately $10,040-$12,000. Construction is scheduled to begin in January but is weather dependent. When the water level is lower than the outlet (existing condition), the lack of flow-through results in poor water quality, as evidenced by increases in algae. The modification of the existing outlet will allow staff to manage water flows depending upon water availability. With the existing outlet height, the lake has a surface area of 2.4 acres. By lowering the outlet, the surface area of the lake could be reduced to 2 acres, and could create aflow-through system that results in improved water quality. AGENDA ITEM # 5 PAGE 5 ANALYSIS: Eight options for management of Thunderbird Lake have been evaluated and are presented here for discussion. tVlarragement 4~tions • No Action* • Adaptive Managements (Original Option 4) • Potable Water • Groundwater Well (Original Option 3) • RetrofittedlLowered Tile Drain (Original Option 1) • Stormwater (Original Option 2) • Diversion from Bear Canyon Creek These options do not involve adding supplemental water. The options were assessed using the following evaluation criteria: • Water rights • Sustainability • Feasibility/implementation • Wetland habitat • Neighbors' desires • Wetland permitting • Policy implications • Timeframe to implement • Cost A brief summary of each option is discussed below. Amore detailed analysis of the options may be found in Attachment A and a matrix that compares the options is included as Attachment A-1. (These attachments were included in the December 15, 2008 WRAB packet.) No Supulemental Water Two management options do not include the addition of water to the lake and expected results and management actions are described below. • Option A: No Action Staff would manage the lake and surrounding area according to current department park maintenance standards (mowing, trash removal, irrigation, health and safety repairs). In addition, the existing the drain would be maintained so that groundwater, if available, could enter the lake. This option meets most of the evaluation criteria; however it would not meet the aesthetic desires of the neighbors. Cost Estimate: $10,500 - $14,500 AGENDA ITEM # 5 PAGE 6 • Option B: Adaptive n'Ianagement Adaptive management, as described in the U.S. Department of Interior Technical guide, is characterized "as an iterative learning process producing improved understanding and improved management over time" (see Attachment A-2). Staff would initially manage the lake and surrounding area in the manner established in 2008, and monitor and make adjustments based on the goals established in a management plan, including water quality goals. Enhancements and capital projects would be explored, including re-assessment of the park amenities, the addition of a boardwalk or dock and the re-configuration of the lake. These costs are not presented here. This option would meet most, if not all, of the evaluation criteria and may address the neighbors' desires for a clear, visible lake. Cost Estimate: $37,500 - $52,500 Su~ulemental Water The following management options include the addition of supplemental water to Thunderbird Lake. It should be noted that in periods of drought supplemental water may not be available. For any option that adds supplemental water to the lake, various permits will be required, including a city of Boulder standard wetland permit. If the wetland permit is approved, mitigation for the affected wetland would need to occur either on site (preferred) or at a different location. A slightly smaller lake would be beneficial from a wetland habitat and mitigation perspective, therefore staff recommends that the lake be maintained at a slightly reduced size as discussed in the Biohabitats. Inc. Memorandum of September 17, 2008. • Option C: Potable V4''ater -one fill per year The addition of potable water would be the least costly of the supplemental water options. The amount of water added in this option may be insufficient to provide the desired water quality benefits. This option meets some of the evaluation criteria. Cost Estimate: $77,000 - $139,500 • Option D: Potable Water -multiple fills per year The Water Utility has established a potable water budget for Thunderbird Lake that is based on Block Rates. While filling the lake multiple times per year would have a slightly higher cost due to modifications to the irrigation system and the cost of the additional water, this option is more likely to improve water quality and meet the neighbors' desires for a clear, visible lake. This option meets some of the evaluation criteria. Cost Estimate: $89,000 - $158,500 • Option E: Groundwater Well The groundwater well option is viable from water availability and water quality perspectives. In order to proceed with this option, a well permit and augmentation plan will be required because the well would extract water from a depth lower than the existing the drain, which is not allowed within the associated water right decree. Additional grounder-ater data is required to develop an augmentation plan. This option would meet some ofthe evaluation criteria and would likely address the neighbors' desires for a clear, visible lake. The cost associated with conducting the groundwater research is $22,000 - $47,000. Total initial costs for this option would include legal fees, AGENDA ITEM # 5 PAGE 7 research, and engineering and construction costs. This process would take 30 to 48 months to implement. Cost Estimate: $279,544 - $593,500 • Option F: Retrofitted/Lowered Tile Drain When originally evaluated, the scope of this option was to repair or retrofit the existing the drain at its existing location. Data fiom groundwater monitoring demonstrated that the groundwater level is below the the drain. As a result, staff has researched the possibility of lowering the the drain to intercept more groundwater. Consultation with the city's water attorney indicates that water court approval or a change of water right would be required in order to lower the the drain. This process is complex and would involve the possible reassessment of the existing water right. The amount of additional water resulting from this option is uncertain, since it is dependent on the availability of groundwater. Due to these factors, this option meets few of the evaluation criteria and would not meet the neighbors' desires for a clear, visible lake. Total initial costs for this option would include legal fees and engineering and construction costs. Cost Estimate: $389,500 - $728,500 • Option G: stormwater The stormwater option, as originally referenced in the February 25, 2008 PRAB memo, would have coordinated with a stormwater management project identified in the Boulder stormwater Master Plan. However, the stormwater management project is a lower priority for Public Works/Utilities and, when originally considered, this option was the most expensive to implement due to extensive infrastructure development costs. Therefore, Biohabitats, Inc. assessed a modified stormwater option using existing infrastructure (diverting stormwater runoff into existing drain lines and catch basins). Concerns remain about water availability and water quality. This option meets few of the evaluation criteria and is unlikely to meet the neighbors' desires for a clear, visible lake due to the dependence on rainfall and water quality considerations. Cost Estimate: $359,500 - $601,500 • Option H: Diversion from Bear canyon creek Upon reviewing the analysis of the water rights needed for a groundwater well, it was suggested that it might he easier to divert city-owned water shares from Anderson Ditch through Bear Canyon Creek to Thunderbird Lake. The water would be available from April through October. This option would require infrastructure development such as installing a pipe under the University of Colorado (CU) property and under Caddo Parkway from Erie Drive past Inca Parkway (approximately 2,700 feet). In order to accomplish this, an easement would be needed from CU; however, staff was notified by a CU representative that granting an easement would not fit with current development plans. Additionally, further analysis would be needed in order to file an application to water court for a change of use. This option satisfies some of the evaluation criteria and meets the neighbors' desires for a clear, visible lake. This option is one of the most expensive due to significant design and construction costs. Cost Estimate: $454,500 - $766,500 AGENDA ITEM # 5 PAGE 8 A more comprehensive review of each option, including the evaluation by the aforementioned criteria may be found in Attachment A. Funding The department prioritizes parks and recreation facility development based on criteria identified in the master plan. Priorities include providing safe parks and facilities, maintaining the current system, complying with the 1995 Ballot Initiative and re-investing in revenue producing facilities. While criteria are included in the master plan, they are intended to be flexible and the rationale for specific capital projects is reviewed each year by the PRAB, Planning Board and City Council during the budget process. During the 2009 budget process, staff included $200,000 in the Capital Improvement Program (CIP) budget in Fund 118 (.25 Cent Sales Tax Fund) for potential capital actions at Thunderbird Lake, recognizing that a plan of action had not been determined. If the initial capital cost of the recommended management option is in excess of $200,000, staff will review the CIP budget for 2010 and beyond and return to the PRAB with a list of potential trade-offs. Potential sources of funds for implementing the capital aspects of the management option for Thunderbird Lake are Fund 230 (Permanent Parks and Recreation), Fund 118 (.25 Cent Sales Tax Fund) and Urban Parl:.s Renovation and Refurbishment funds (Fund 230 and Fund 118). Since those funds are currently allocated, the monies for project implementation at Thunderbird Lake will require that currently identified CIP and major maintenance projects be deferred. Outside of the capital funds, ongoing maintenance costs for the recommended option will be calculated and budgeted in the Parks and Planning Division's operating budget, resulting in internal re-prioritizations and reallocations causing a decrease in levels of service. Service reductions could be seen in such areas as park maintenance, urban Integrated Pest Management (IPM), prairie dog management and seasonal staffing. QUESTIONS FOR the WRAB: 1. Does the WRAB support the PRAB's and staff's recommendation of Option B, Adaptive Management - No Supplemental Water? 2. If the WRAB does not support the PRAB's and staff's recommendation, which option does the WRAB recommend to City Council? ¦ Option A - No Action Or Addition of Supplemental Water ¦ Option C -Potable Water (one fill per year) ¦ Option D -Potable Water (multiple fills per year) ¦ Option E groundwater Well ¦ Option F -Retrofitted/Lowered Tile Drain ¦ Option G -Stormwater ¦ Option H -Diversion of Anderson Ditch Water from Bear Canyon Creek AGENDA ITEM # 5 PAGE 9 NEXT STEPS: The WRAB's recommendation will be provided to the City Council along with the PRAB's recommendation and public comment. A public hearing before City Council is scheduled for February in order to make a final decision and implement approved management actions for 2009. Based on the management option selected by City Council, staff will develop a management and implementation plan that includes a task list, schedule, detailed cost estimate, on-going maintenance costs and potential funding sources. Staff may return to the PRAB and/or the tA~RAB at a future date for a discussion of the implementation plan, cost estimates and any needed trade-offs. ATTACHMENTS: (Attachments A throrigh B were included in the December 15, 2008 WRAP paclret anal are not provided with this memo.) Attachment A: Evaluation of Management Options for Thunderbird Lake Attachment A-1: Analysis of Management Options Attachment A-2: U.S. Department of the Interior Technical Guide, Executive Summary on Adaptive Management Attachment A-3: Diagram of the Adaptive Management Process Attachment B: Cost Estimates for Thunderbird Lake Management Options Attachment C: Response to Questions from WRAB Members AGENDA ITEM # 5 PAGE 10 Attachment A City of Boulder Parks and Recreation Department Evaluation of Management Options for Thunderbird Lake December 2008 Eight options for management of Thunderbird Lake have been evaluated and classified into two main categories: no addition of supplemental water (two options) or the addition of supplemental water (six options). The evaluation was performed in order to determine the best method to address water quality and neighbor concerns. The options were assessed using the following evaluation criteria: • water rights • sustainability • feasibilitylimplementation • environmental factors • neighbors' desires (to see a clear lake surface and have access to the water) • wetland permitting • policy implications • timeframe to implement • cost For each of these options, it is assumed that the existing water right decree remains viable. The the drain system that was scoped and cleaned in 2007/2008 will be maintained ($2,000 - $4,500). The outlet will also be lowered for each option ($10,000 - $12,000). For each option community education and outreach would be beneficial in order to address concerns and keep the public informed as to the process and progress. As was discussed during the February 25 Parks and Recreation Advisory Board (PRAB) meeting, this would also include interpretive sings being posted around the lake. The cost would be approximately $8,500 - $10,000 for the first year and is included for each option. NO ADDITION OF SUPPLEMENTAL WATER The two options that do not add supplemental water to the lake as part of the management plan are Option A - No Action and option B -Adaptive Management. There are no special circumstances that apply strictly to these two methods. ADDITION OF SUPPLEMENTAL WATER The six options that do add supplemental water to the lake as part of the management plan are described below. For each of these options, the Adaptive Management items listed above may be performed in addition to adding water to the lake (no matter the method) and some may still need to be performed if addition of supplemental water is not sufficient to address the concerns on its own. The items incorporated would be dependent upon factors such as the amount of water, water retention and the effects upon the ecosystem such as water quality. Page 1 of 21 Attachment A The premise of adding water is that it was thought to be the best way to address the desires of some neighbors. They have expressed an interest in being able to see the water, having the water surface clear of vegetation, having access to the lake and potentially having fish restored to the lake. Improved water quality is a factor in obtaining these results and while the microbes and Solar Bee® assist in this function, a flow-through system would increase the effects. The visibility of the water and the access can be addressed by either adding water to the lake or in other ways such as the installation of a boardwalk. If water is to be added to the lake, more groundwater monitoring wells may need to be installed to determine the potential for the lake to be connected to the groundwater. In some instances a few more monitoring wells may need to be installed to determine the conditions between the water source and South Boulder Creek. This is further explained in the memorandum from AlVIEC. The groundwater monitoring wells could be installed in approximately t~~-~o months for between $14,444-$27,404 dollars, depending upon the number of monitoring wells. Some of the existing (9) monitoring wells would also need to be permanently permitted at $250/each. Permits and Mitigation Per city ordinance, any option that adds water to the lake would require that a "standard wetland permit" be obtained ($5,440 - $8,444) in order to change the hydrology and habitat of the wetland area. A mitigation plan for the affected wetland area is part of the permit application. The permit is issued by the Planning and Development Services department (P&DS) and approval is based upon the factors set forth in the wetland ordinance. If approved, the permit may contain conditions that are required to be met which can increase the cost of the project. If the permit is not approved by the P&DS department, it can be called up by the Planning Board and if not approved by that body, it can be called up to City Council. The process can take anywhere from 3 to 8 months. If approved, mitigation would need to occur once. The ratio of affected habitat to the amount of habitat that would need to be created would depend upon the type of mitigation. If a wetland could be restored, the mitigation ratio would be less than if one needs to be created. Typically the ratio is 2:1 for creation and 1.5:1 for restoration. There may be justif°ication for lower ratios if some of the wetland functions are able to be kept versus totally destroying the wetland areas that are impacted. Mitigation costs vary significantly since they are very site specific. Staff and Biohabitats recommend not filling the lake to its historic 2.4 acre surface area. For the options that add supplemental water, the recommendation is to add enough water to obtain 2.0 acres in surface area (up from the approximate 1.5 acres it is now). The desires of the neighbors should still be met and there would be less impact upon the existing habitat. This would better meet the wetland permitting requirement to show that impacts to the wetlands were avoided or minimized. A change to the wetland with mitigation within the buffer around the wetland to replace some of the impacted functions on site would range in cost from $24,444 to $54,404. If off-site mitigation or creation of anew wetland is required the cost estimate could be up to $244,444 per acre. Page 2 of 21 Attachment A Potable Water Overview For any option that adds potable water to the lake, an annual Colorado Department of Public Health and Environment (CDPHE) Minimal Industrial Discharge (MINDI) permit is required. A permit is required to have any discharge/flow out of the lake via the outlet and a permit is necessary because the lake is not likely lined and has the potential to recharge the groundwater. One permit can cover both of these issues. The permits typically have a 30-day review period. They are generally approved, but with conditions such as necessary monitoring, sampling and flow metering. The MINDI permit was waived for the addition of «~ater earlier this year but would be required in the future. The cost for the permit is currently $630 per year. Using potable water would be the least costly supplemental water option because the other options require significant monitoring and an application to the water court for approval of an augmentation plan and/or change of the terms of a water right. The Water Utility staff and Parks and Recreation Department staff have developed a tentative plan for along-term water rate structure for the possible addition of potable water to Thunderbird Lake only. This plan is compatible with but separate from the city's newly- adopted water budget billing structure and will supplant previous cost estimates for use of potable water. These previous estimates were based on the city's bulk water rate for users such as water hauling companies that fill from a designated tap at the city's maintenance complex. The 2008 rate for this type of use is $8/1000 gallons or $2607/acre foot (af). The proposed payment plan would set the budget for potable water for Thunderbird Lake based on the average annual net evaporation amount (total evaporation less the amount offset by precipitation) estimated to occur from the lake surface. The net evaporation would become the amount defined as 100 percent of the annual budget for this use. Therefore, the Parks and Recreation Department would pay the Water Utility at Block 1 rates ($1.95/1000 gallons in 2008) for use up to 60 percent of the budgeted amount and Block 2 rates ($2.60/1000 gallons in 2008) for the remainder of the budgeted amount. Total potable water usage would be expected to stay at or below 100 percent of the budget, but if it did not, payments for the additional water would be made at the higher rates for Blocks 3, 4 or 5 in accordance with the established water budget rate procedure. In 2008, these rates range from $5.20/1000 gallons to $13.00/1000 gallons. This proposal is contingent on a commitment to maintain the existing the drain to obtain flows into the lake that would offset seepage and provide for flow-through needs based on the existing water right for the drain tile. Under the proposal, potable water available to the lake would be reduced during droughts severe enough to affect the entire municipal water system. The water budget would be reduced in drought years, with corresponding higher charges if potable water use for the lake was not reduced accordingly. In more severe droughts, potable water use for this purpose could face mandatory restrictions or complete elimination. This year, the Department paid the city Water Utility $100/af for water discharged into Thunderbird Lake on a one-time basis only. This rate was based on the cost to bring Windy Gap Project water over from the western slope through the Colorado-Big Thompson Project facilities specifically for this purpose. The payment covered only the pumping and delivery costs for the Windy Gap water. It did not cover any of the capital Page 3 of 21 Attachment A cost for the water, treatment costs, pipe infrastructure costs or any of the other costs incurred by the Water Utility in delivering treated water. Therefore, the $1Q4/af rate should not serve as the basis for along-term commitment for the provision of potable water for Thunderbird Lake. Options E -Hall require some version of water rights implications. While going through the water rights process, our existing water right may be called into question. If this happens, a change in the existing water right decree may also be needed. Each of the options described below is susceptible to being affected by drought and is in no way a guarantee that water would be provided during such periods. Options A-H are presented as follows and a graphic representation of this information is provided in Attachment A-1: Analysis of Management Options. No Supplemental Water Option A - No Action Page 5 Option B -Adaptive Management. Page 6 - 7 Addition of Supplemental Water Option C -Potable ~~~'ater -One Fill per Year Page 8 - 9 Option D -Potable Water -Multiple Fills per Year Page 1(~ - 11 Option E -Groundwater Well at 8.5 or 3 gpm Page 12 - 14 Option F -Retrofitted/Lowered Tile Drain Page 15 - 16 Option G - Stormwater Page 17 - 18 Option H -Diversion from Bear Canyon Creek Page 19 - 21 Page 4 of 21 Attachment A OPTION A - NO ACTION Analysis of Evaluation Criteria Water Rights • Not applicable if no addition of water. .S'ustainability • 1Vlost sustainable option as it would let the water stabilize given current circumstances. Feasibility/Implementation • Most feasible option as there would be no new practices to implement. Environmental • The ecosystem would evolve and if water did not increase naturally, it would likely transform into a more vegetative wetland with more diverse habitat value. Neighbors' Desires • Would not meet the expressed desires of some of the neighbors. Wetland Permitting • Would not require a wetland permit. Policy Implications • None Total Estimated Timeframe to Implement • Immediate Total Estimated Cost: ~$10, 000 - $14,504 for the first year • Capital/Initial set-up: $8,504 - $10,444 • Legal: none • Ongoing: $2,444 - $4,544 for the the drain 0 other maintenance is already incorporated into budget Additional Information This option would control for potential health issues but would not provide the clear, visible lake some of the neighbors have requested. Staff would manage the natural area around the lake and the lake itself as it was prior to the drought of 2442. IVlanagement actions would focus on the health and safety of the public and include the following actions: • weed control (part of staff work plans, so no additional cost) • mosquito mitigation (part of existing contract) • other health and safety tnanagetnent actions • maintenance Page 5 of 21 Attachment A OPTION B -ADAPTIVE MANAGEMENT Analysis of Evaluation Criteria YT~ater Rights • Not applicable if no addition of water. Sustainability • Sustainable as this option would let the water stabilize given current circumstances but requires increases in staff resources. Feasibility/Implementation • With exception of major maintenance/capital items, this option is very feasible as there would be no new practices to implement. The major maintenance/capital items vary in feasibility and are in order from most to least feasible. Environmental • The system would evolve and if water did not increase naturally, it would likely transform into a more vegetative wetland with more diverse habitat value. Neighbors' Desires • 1VIay meet some to most of the neighbors' desires depending upon which items are performed. i~Vetland Permitting • Would not require a wetland permit. Policy Implications • None Total Estimated Timeframe to Implement • Immediate to one year for major maintenance/capital items. Total Estimated Cost: $37, 500 - $52, 50(1 for th e first year • Initial set-up: $8,544 - $14,444 o Additional costs may be incurred if maintenance and major maintenance/capital items are chosen • Legal: none • Ongoing: $29,444- $42,544 Page 6 of 21 Attachment A OPTION B -ADAPTIVE MANAGEMENT Additional Infot~nxation As defined in the Boulder Valley Comprehensive Plan (BVCP), "an adaptive management approach involves ongoing monitoring of resource conditions, assessment of the effectiveness of management actions, revision of management actions based on new information from research, and learning from experience what works and what does not." The adaptive management approach is more fully explained in Attachment A-2: Adaptive Management -The U.S. Department of the Interior Technical Guide Executive Summary which can be found at httpa,,'www.doi.~ov-'initiatives/AdaptiveMana~ernent~'documents.html and an illustrative guide to the process is provided in Attachment A-3: The Adaptive Management Process. This approach would be utilized at Thunderbird Lake with the intention of improving water quality and decreasing neighbor concerns. This option would incorporate and go beyond the "No Action" option. It would attempt to address the neighbors' concerns. This option would maintain and potentially go beyond the current level of management being performed at the lake. Staff would manage the natural area around the lake and the lake itself including the following actions: • weed control (part of staff work plans, so no additional cost) • mosquito mitigation (part of existing contract) • adding microbes to decrease algae and sludge ($4,000 - $5,000/year) • maintaining Solar Bee® circulation unit ($1,000 - $1,500/year) • water quality sampling ($1,000 - $2,500/year) • removing duckweed ($1000 - $5,000/year)1 • continuing management of the trees along the shoreline including thinning per the best management practices ($500 - $1,000) • maintaining simple wetland permit and clearing of viev~~ corridors ($1,500 - $3,000 includes permit and consultant fees) o permits may or may not be approved; permits take approximately 1-2 months to obtain and need to be re-issued every three years These actions would be assessed for effectiveness and further management actions would be determined based upon this information and new information or research. Staff may also perform one or all of the following actions: • Maintenance o adding an aeration unit or a fountain to improve water quality • Major Maintenance/Capital o adding a boardwalk and dock to improve views and access to the lake ¦ A wetland permit would be required. o re-assessment of other amenities o reconfiguring the lake Page 7 of 21 Attachment A OPTION C -POTABLE WATER -ONE FILL PER YEAR Analysis of Evaluation Criteria YVater Rights • No water right application would be needed for this option because the potable water will come from City water rights that are already legally decreed for all municipal uses. Sustainability • Water will be available as long as there are no drought restrictions. City Council previously adopted reliability criteria for the Water Utility with the goal of meeting all municipal water demands up to droughts severe enough to occur no more often than once every 20 years on average. As long as a drought stage has not been declared and no emergency situation exists with water system facilities, water will likely be available from the municipal system to fill the lake. Therefore, water should be available for purchase in approximately 19 out of 20 years. Some stafF oversight and maintenance would be required. Feasibility/Implementation • Feasible assuming the standard wetland permit is obtainable and mitigation possible. Environmental • Depending upon the amount of water added, the existing habitat may be minimally to mostly altered from emergent/wetland and upland~`riparian habitat to a small amount of emergent/wetland vegetation and more aquatic habitat. This would be a less diverse habitat overall. Neighbors' Desires • Will meet some of the neighbors' desires at least while lake retains water. Would meet more if some of the Adaptive Management items were performed in conjunction. Wetland Permitting • Required Policy Implications • This would set a policy precedent related to filling other city lakes. Total Estimated Timeframe to Implement • 3-8 months depending upon permitting process but not including mitigation time. Total Estimated Cost: $77,t10d - ~139,5(1t1 for the firstyear • Initial set-up: $35,000 - $75,500 • Legal: none • Ongoing: $42,000 - $64,000 Page 8 of 21 Attachment A OPTION C -POTABLE WATER -ONE FILL PER YEAR Additional Infot~rraation Filling of the lake could be accomplished each year by working with the city Water Utility to tap into a nearby fire hydrant. This method was used to add water to the lake in 2008. The hydrant produced 250-325 gallons per minute (gpm) and provided 525,000 gallons of water 0$244 per the 2448 rate but future years will be subject to the rate structure described above) in about five days (running approximately seven hours per day). This could be done at any time of the year, subject to priority needs of the water system to meet municipal demands. This process invohres: • metering the amount of water o $6,500 to fill the first year and about $3,000 each year thereafter - given 2008 potable water rates and only filling to 2 acres in surface area o $15,500 to fill the first year and about $3,500 each year thereafter - given 2008 potable water rates and filling to about 2.4 acres in surface area • putting the water through a de-chlorination chamber ($2,000 - $4,000) • running a fire hose across the street • signage for traffic and a speed bump to protect the hose • diffusing the water with a diffuser and straw matting to decrease sediment disturbance • a staff person on site to monitor flow and chlorine content • water quality sampling ($1,000 - $2,504/year). Page 9 of 21 Attachment A OPTION D -POTABLE WATER -MULTIPLE FILLS PER YEAR Analysis of Evaluation Criteria YT~ater Rights • No water right application would be needed for this option because the potable water will come from City water rights that are already legally decreed for all municipal uses. Sustainability • Water will be available as long as there are no drought restrictions. City Council previously adopted reliability criteria for the Water Utility with the goal of meeting all municipal water demands up to droughts severe enough to occur no more often than once every 20 years on average. As long as a drought stage has not been declared and no emergency situation exists with water system facilities, water will likely be available from the municipal system to fill the lake. Therefore, water should be available for purchase in approximately 19 out of 20 years. Some stafF oversight and maintenance would be required. Feasibility/Implejnentation • Feasible assuming the standard wetland permit is obtainable and mitigation possible. Environmental • Depending upon the amount of water added, the existing habitat may be minimally to mostly altered from emergent/wetland and upland~`riparian habitat to a small amount of emergent/wetland vegetation and more aquatic habitat. This would be a less diverse habitat overall. Neighbors' desires • Should meet the Neighbors' desires especially if some of the Adaptive Management items were performed in conjunction. Wetland Permitting • Required Policy Implications • This would set a policy precedent related to filling other city lakes. Total estimated timeframe to implement: • 3-8 months depending upon permitting process but not including mitigation time. Total Estimated Cost: $89, 0©0 - $Y58,500 for the first year • Initial set-up: $40,000 - $85,500 • Legal: none • Ongoing: $49,000 - $73,000 Page 10 of 21 Attachment A OPTION D -POTABLE WATER -MULTIPLE FILLS PER YEAR Additional Information The lake could once again be filled fiom a fire hydrant; however if potable water is to be used on a recurring basis, it may be easier to retro-fit the existing irrigation system with one or two lines discharging into the lake. This method could provide 140-200 gpm. This would need to be worked within the current irrigation schedule and this rate would require more time to fill the lake. One of the existing irrigation system taps is near electricity and would therefore be easier to winterize. Filling could then be done between mid-March and mid-December {9 months}. This would incur some construction costs for the new line and, potentially, a cobble bed to assist with de- chlorination ($5,440 - $14,440). Page 11 of 21 Attachment A OPTION E -GROUNDWATER WELL at $.5 or 3 gallons per minute (fpm) Analysis of Evaluation Criteria Mater Rights • The existing water right is not able to be utilized because the well would tap into a part of the underground aquifer that the existing system could not. A well permit would be required. This well is not exempt and would therefore require a plan for augmentation prior to the permit being issued. An augmentation plan would require that a depletions study/MODFLOW analysis ($10,000 - $15,000) be performed to find out where the water for the well would be removed from and where it would need to be augmented back to. In order to perform a depletions study, eight to nine more groundwater monitoring wells may be needed. Once this data is obtained and the depletions study complete, an augmentation plan could be written, negotiations held with objectors to the plan, and, if no settlement on terms to protect against injury to other water users can be reached, trial preparation and participation would occur ($10,000 - $35,000). Replacement water for an augmentation plan may be hard to secure and expensive depending upon the location of the depletions, mainly Boulder Creek and likely some South Boulder Creek. Water rights to augment depletions to Boulder Creek may be available for purchase from the City Water Utility, but private sellers would need to be sought for water rights on South Boulder Creek. Also, it may be easier to gain use of reservoir storage space for augmentation water on Boulder Creek than on South Boulder Creek as described in the AMEC memorandum. The delayed effect from well pumping would need to be tracked for every day that the well operates and provisions made to have water available when the depletion affects the river. It may require two to four hours a week for a staff person to do the augmentation accounting. For depletions to Boulder Creek, water such as Anderson and Farmers Ditch could be acquired, either from the City Water Utility or from a private seller. For South Boulder Creek, Howard or Dry Creek No. 2 shares could be acquired from private sellers. The water shares would need to he changed through water court to allow augmentation and storage in a reservoir above the point on the stream affected by the well depletions. The augmentation water could then be released as needed to match depletions occurring to the river during the winter when the ditches that are the source of the augmentation water are not operating. Since reservoir storage is likely to be at a time when the space in Barker Reservoir would otherwise he filled with municipal water, a small reservoir on Boulder Creek might need to be constructed. For any depletions that occur to South Boulder Creek, the Department would have to construct a reservoir since the Water Utility does not own any reservoir storage on South Boulder Creek suitable for this use. Abroad estimate of cost to acquire shares yielding sufficient augmentation water would be $40,000 to $80,000. Augmentation methods such as the storage facility must be in place. Cost of constructing a small reservoir of about 10 acre-feet might be in the range of $50,000 to $120,000. Page 12 of 21 Attachment A OPTION E -GROUNDWATER WELL at 8.5 or 3 fpm (continued) The substitute water supply plan mentioned in the memorandum from Ronni Sperling could be approved during the time the application for approval of a plan for augmentation and/or change of water rights is pending in water court. This would mean that all potential objectors would need to be notified rather than simply allowing objectors to come forward. It would also require that the storage requirements, if any, be in place beforehand. Although the water right will be a junior right, there will also be an augmentation plan and therefore the well can pump (including during droughts) even though its water right is out-of-priority as long as a water supply is available to augment the well depletions. Thus, with a secure augmentation supply, the well will he able to provide water to the lake year round unless the well itself dries up. Sustainability • Sustainable even during most drought years if the augmentation plan is solid enough to account for drought. The water right will be an augmented junior right that can only he pumped if augmentation water is available to satisfy senior water rights. A shortage of augmentation water would mean that the well can't be used at that time. This situation could happen in serious drought years, which might occur every 10 to 25 years. • Sustainable if the well does not go dry. Feasibility/Ittapletnentation • Feasible from water outflow and quality perspectives. Dependent upon ~~~ater rights. More "fi•ont-end" information is needed initially than other options but similar in monitoring and tracking tune at least for Diversion to Bear Canyon Creek option. Environmental • Depending upon the amount of water added, the existing habitat may be minimally to mostly altered fiom emergenthwetland and upland/riparian habitat to a small amount of emergent/wetland vegetation and more aquatic habitat. This would be a less diverse habitat overall. Neighbors' Desit~es • Should meet the neighbors' desires especially if some of the Adaptive Management items were performed in conjunction. Wetland Permitting • Required Policy Implications • None Page 13 of 21 Attachment A OPTION E -GROUNDWATER WELL at 8.5 or 3 fpm (continued) Total Estimated Timeframe to Implement • 30 to 48 months Total Estimated ~'ost: $279,S1IQ - $593,5/1Q for the fit~st yeah • Initial set-up: $168,500 - $333,000 • Legal: $25,000 - $100,000 • Ongoing: $86,000 - $160,500 Additional Information As part of the groundwater monitoring and well feasibility evaluation, a monitoring well has already been drilled at the corner of Inca and Caddo Parkways. (This monitoring well cannot be used for filling the lake without a well permit and a plan for augmentation.) This monitoring well was found to have a sufficient water supply for up to an 8.5 gpm rate. The 3 gpm rate would still provide outflow and, over the long term, would be more desirable from a water rights augmentation perspective. It may not allow for a good initial flushing of the system. A higher than 3 gpm amount could be settled upon for the augmentation plan to cover flushing the system and then the amount of actual use can be adjusted back down on a regular basis. The augmentation plan obligation is only to augment whatever amount is actually pumped, so the higher rate could be decreed but would not have to be used nor would it need to be augmented if it was not used. However, if the higher rate is decreed and the well does not ultimately pump into the lake at that rate, the gpm rate in excess of what is actually pumped might eventually be cancelled in a diligence case. Implementation time is dependent upon the level of input received by objectors and the State Engineer's Office. A pumping station would still need to lie installed to transform the monitoring well to an extraction well. This would include connecting to a power source (~$55,000~$65,000). Page 14 of 21 Attachment A OPTION F -RETROFITTED/LOWERED TILE DRAIN Analysis of Evaluation Criteria YT~ater Rights • The existing water right is anon-tributary water right, and it is not administered within the priority system. Initial information suggested that the the drain could be repaired or realigned within 200 feet of its current location without water court approval (under the existing water rights decree). Staff began to explore the potential to lower the the drain to meet the groundwater. It was later determined by the city's water right attorney that while the the drain could be re-aligned within 200 feet, it could not be lowered without water court approval or a change of water right for the existing the drain water right, as it may result in diversion of water from a different source or in amounts greater than those available from the original depth. Filing an application with the water court for a change of this water right will likely put the current decree's non-tributary finding concerning the water right at issue, with the risk that the non-tributary finding could be modified by the court. If the source of water for the the drain water right is found to be tributary groundwater, then the water right will thereafter be subject to administration within the priority system, similar to the process described for the groundwater well. Sustainability • This option is not sustainable. The amount of the additional water that could be obtained is unknown. It relies upon rain and other groundwater sources that fluctuate. If the the drain is lowered, the water table could drop even further. Feasibility/Ittapletnentation • A large portion of the the drain was cleaned and scoped and found to be in good repair. Groundwater monitoring wells were installed and the water table was found to be lower than the the drain and therefore, the only water reaching the the drain is fiorn rain or other surface permeation. Given the water rights implications of retrofitting the the drain, the unknown feasibility of being able to lower the the drain and the fact that it would still rely on intermittent sources, this option is minimally feasible. Environmental • Depending upon the amount of water added, the existing habitat may be minimally to mostly altered from emergenti'wetland and upland%riparian habitat to a small amount of emergent/wetland vegetation and more aquatic habitat. This would be a less diverse habitat overall. 1Veighbors' ?esires • IVIay not meet any of the neighbors' desires especially without Adaptive 1Vlanagement items as well. Wetland Permitting • Required Page 15 of 21 Attachment A OPTION F -RETROFITTED/LOWERED TILE DRAIN Policy Implications • None Total Estimated Timeframe to Implement • 30 to 48 months Total Estimated Cost: $389, SflI1- X728, S©f/ fot~ the fit~st yeah • Initial set-up: $278,500 - $468,000 • Legal: $25,000 - $100,000 • Ongoing: $86,000 - $160,500 Additional Infot~mation This option has changed from its original intent. In February the PRAB asked staff to further investigate the condition of the existing the drain to determine if by cleaning and repairing it, flows might be increased into the lake. The main section of the the drain was cleaned and scoped and found to be free of blocks or breaks. From the installation of the groundwater monitoring wells, it was determined that the the drain is situated higher than the groundwater level; therefore, staff did not pursue the process of finding, accessing, cleaning and scoping the rest of the the drain. Page 16 of 21 Attachment A OPTION G - STORMWATER Analysis of Evaluation Criteria YT~ater Rights • The existing water right could not be utilized for this option as it would potentially collect water that would not have made it into the the drain. No decreed water right is required to run storm water through Thunderbird Lake proj~ided no storage occurs (i.e. the same amount of storm water that enters the lake must flow out of the lake). Storm water can be stored in Thunderbird Lake during free river periods (when there are no downstream "calls" for water by decreed water rights.) If storage occurs during periods of "call," a decreed water right and an augmentation plan is required unless any storm water stored out of priority is released from, or pumped out of, the lake within a short time after the storage occurs, generally within 24-72 hours of the storage. These requirements would apply whether the storm water is directed into the the drain before being delivered into the lake, or delivered directly into the lake." There would need to be great attention toward monitoring the inflow and outflow of water on a daily basis. Sustainability • An average precipitation year may provide enough water but drier years will not and water is only available during storm events. Feasibilityflmplementation • The nutrient load would be higher and therefore ~~~ater quality would be lower likely causing more management issues in regard to fish, algae and other vegetation. A treatment wetland created on the western side of the lake may help to offset the nutrients and pollutants. Significant staff time would be required to prevent water rights violations without obtaining a decreed water right. Obtaining a decreed vt~ater right is similar in feasibility to the ~~~ell option. Environmental • Depending upon the amount of water added, the existing habitat may be minimally to mostly altered from emergent/wetland and upland/riparian habitat to a small amount of emergent/wetland vegetation and more aquatic habitat. This would be a less diverse habitat overall. Neighbors' Desires • May not meet the neighbors' desires without Adaptive Management items. Wetland Permitting • Required Policy Implications • None Total Estimated Timeframe to Implement • Greater than 12 months without the water right and 34 to 48 months with the water right. Page 17 of 21 Attachment A OPTION G - STORMWATER Total Estimated Cost: $359, Sf1(1- $G(11, 500 for the first year • Initial set-up: $248,500 - $341,000 • Legal: $25,000 - $100,000 • Ongoing: $86,000 - $160,500 Additional Information The original stormwater option involved worl~ing with Public Worl~s on future improvements and the creation of a new system per the Boulder stormwater Master Plan. As the option was found to be expensive and less feasible than others, but was still an expressed interest, the option was modified to evaluate tying into the existing system. Page 18 of 21 Attachment A OPTION H -DIVERSION OF ANDERSON DITCH WATER FROM BEAR CANYON CyREEK Analysis of Evaluation Criteria Mater Rights • A change of use analysis would need to be performed on a share of the Anderson Ditch Company and associated water right that the City Water Utility currently has and would be willing to sell or lease to the Parks and Recreation Department. The portion of the water associated with the share from the Anderson Ditch that had historically been fully consumed could be released into Bear Canyon Creek at the end of the Anderson Ditch at Table Mesa and Broadway. The water could then be diverted out of Bear Canyon Creek and into an extension of the drain the line. This use of Anderson Ditch water diverted out of Bear Canyon Creek would involve a change of use proceeding through the Water Court to allow the water right to be used in a location other than the historic place of use and to store the water in the lake where it would be used for aesthetic, wildlife, recreation, piscatorial (relating to fish) and related uses other than just the currently decreed irrigation use. Therefore, it would require an analysis of the historic use of the water to identify the historic return flow pattern fiom that use in order to continue that pattern so that downstream water rights that had depended on the return flows would not be injured. Once the historic return flow pattern is quantified, on-going releases would need to be made to replicate any return flows that were not offset by the new use of the water in the lake. Winter return flow obligations from the historic use, if any, would be to Boulder Creek or Bear Creek based upon the location of the historically-irrigated Anderson land. During the irrigation season, a portion of the divertible Anderson water can either be left at the headgate at Boulder Creek or released down Bear Creek to cover the return flows that were generated by the historic use of the Anderson water. When Anderson is not running, the water to replace historic return flows will have to come from a reservoir. Following a water court change proceeding, non- irrigation season return flow obligations, if any, could be made up by storing a small portion of the Anderson share yield in Barker Reservoir during the irrigation season for later release in the winter. If the Anderson water were stored beginning in late August, it is likely that it could most often be stored in space that had been already emptied of its municipal water for the year. Costs would be approximately a few hundred dollars annually to cover administration, accounting and release of the water. It should be noted that this option is a direct use of Anderson water for the lake and no water will be available for delivery into the lake when Anderson Ditch is not running from about mid-October until mid-April. If the Department were to acquire 1/2 share of Anderson water from the Water Utility or from another seller, the cost would be about $4Q,00~ - $45,00. Page 19 of 21 Attachment A OPTION H -DIVERSION OF ANDERSON DITCH WATER FROM BEAR CANYON CyREEK Sustainability • Direct diversion of Anderson Ditch water through Bear Canyon Creek is based on a water right that has historically been decreed for agricultural use; therefore, it would only be available roughly mid- April through mid-October (six months). The Anderson Ditch Company right is very senior (1860) and would yield water during the irrigation season in almost every year. Feasibility/Implementation • Feasibility is dependent upon obtaining an easement over CU property and installing infrastructure among existing systems such as the storm sewer. No augmentation plan is necessary, but on-going coverage of any historic return flows may be required. Monitoring and tracking would slightly less than for an augmentation plan for a well. Environmental • Depending upon the amount of water added, the existing habitat may be minimally to mostly altered from emergent/wetland and upland/riparian habitat to a small amount of emergent/wetland vegetation and more aquatic habitat. This would be a less diverse habitat overall. Neighbors' Desires • Should meet the neighbors' desires especially if some of the Adaptive Management items were performed in conjunction. YVetland Permitting • Required Policy Implications • None Total Estimated Timeframe to Implement • 30 to 48 months Total Estimated Cost: $454, S00 - $766, 5[10 far the first year • Initial set-up: $343,500 - $541,000 • Legal: $25,000 - $100,000 • Ongoing: $86,000 - $125,500 Page 20 of 21 Attachment A OPTION H -DIVERSION OF ANDERSON DITCH WATER FROM BEAR CANYON CyREEK Additional Information Upon analysis of the well, it was determined that, from a water rights perspective, it may be easier to get water from the Anderson Ditch that has been released into Bear Canyon Creek. This option was added to the assessment so that the water rights implications could be evaluated against the design and construction implications. This option would also require an easement agreement with CU. Upon discussions with a CU representative, it was stated that future development is planned for the area and an easement would not be feasible until the plans are complete. There is no current schedule for completion of the plans. Page 21 of 21 Attachment A-Z Ar~alysgs of ~Ia~aagerr€en.t Glati€strs I,egeasd T I ~ Neuhai - I Igo known implications rla t Requires application to water Water Rights Implications ~ court, change of water light and/or an augmentation lan Easy/Probable Neatral Difficult/Impossible Sustainability I j Easy/Probable 1vreauai ~ DiPficuldImpossib7e i Feasibility/Implementation ~ ~I, j V'~o known negative impacis Nenerai ~ Will change existing wetland i Wetland Habitat ~ hydrology and habitatby ~ ~ replacing the diverse vegetative I habitat with a uatic habitat R/lay meet desires ~ 1V1a~~ or may not meet desires ~ May not meet desires Meets Neighbors Desires a No n%a Yes and mitigation required Wetland Permit Needed i either on or off-site i j No known implications ria Sets a precedent related to filling Policy Implications I j ~ other lakes with potable water _ _ i Immediate i! Less than one year ~ Greater than one year; i Timeframe to Implement Likely 3-4 years ~ I Are explained in further detail in attachment B: Cost Estimates for Thunderbird Lake Management Costs ~ Options. I -t -t a fad~~e~,f ~ _ 2 ANALYSIS OF MANAGEMENT OPTIONS (ASSUMES ALL EVALUATION CRITERIA ARE WEIGHTED EQUALLY) WATER RIGHTS SUSTAINA8ILIT'f ~ FEASIBILItt/ WETLAND MEETS WETLAND POLICY TIMEFRAME TO COSTS- COSTS- CO5T5- TOTAL OPTION IMPLICATIONS ~ IMPLEMENT.4 HABITAT NEIGHBORS PERMIT IMPLICATIONS INITIAL TION ~ DESIRES NEEDED IMPLEMENT CAPITAL LEGAL ONGOING COSTS OPTION A +1 i +1 +7 +1 +1 +l NO SUPPLEMENTAL WATER - I I ~ $8,500 - $0 $2,000 - $10,500 - NO ACTION $10,000 $5,000 $14,500 O -1 i ~ r i OPTION B ~ +1 I +1 +i +il +1 NO SUPPLEMENTAL WATER - ~ I , $8,500 - $0 $29,000 - $37,500 - i ADAPTIVE MANAGEMENT i I NEUTRAL I $lo,oo0 542,500 $52sao U OPTION C SUPPLEMENTAL WATER - +1 $35,000 - $0 $42,000 - $77,000 - O ~NEUTRAI NEUTRAL 'NEUTRAL POTABLE WATER ONE FILL - - ! - $75,500 $64,000 $139,500 PER YEAR -7 OPTION D SUPPLEMENTAL WATER - +7 t~ *1 $40,000 - $0 ' $49,000 - 1589,000 - O NEUTRAL NEUTRAL O POTABLE WATER MULTIPLE ~ - $85,560 $73,000 $158,500 FILLS PER YEAR ~ 1 ~ I OPTION E SUPPLEMENTAL WATER- +1 GROUNDWATER WELL ,NEUTRAL', ' NEUTRa-', i NEUTRAL $168,500 • $25,000 - $86,000 - $279,500 - - - $333,000 $100,000 $160,500 $593,500 ~:.a _ i OPTION F SUPPLEMENTAL WATER - i +1 RETROFITTED/ I i i i $278,500 - $25,000 - $86,000 - $389,500 - ~j LOWERED TILE DRAIN -1 it •1 ' -1 I ~ -1 I $468,000 $100,000 $160,500 $728,500 I OPTION G ~ SUPPLEMENTAL WATER - +1 $248,500 - $25,000 - $86,000 - $359,500 - O STORMWATER I $341,000 $100,000 $160,500 $601,500 ,T._ ~ .1 i OPTION H ~ SUPPLEMENTAL WATER - +1 DIVERSION OF ANDERSON $343,500 - $25,000 - $86,000 - $454,500 - DITCH WATER FROM BEAR w,~_i- ' $541,000 $100,000 $125,500 $766,500 CANYON CREEK '1' I I I 'LEGEND INCLUDED ON SEPARATE PAGE A-~-~ Attachment A-2 Adaptive Management U.S. Department of the Interior Technical Guide http://www.doi.~ov/initiatives/AdaptiveMana~ement/documents.html From the Executive Summary: Adaptive management is framed within the context of structured decision making, with an emphasis on uncertainty about resource responses to management actions and the value of reducing that uncertainty to improve management. Though learning plays a key role in adaptive management, it is seen here as a means to an end, namely good management, and not an end in itself. The operational definition used in the guide is adopted from the National Research Council, which characterizes adaptive management as an iterative learning process producing improved understanding and improved management over time: Adaptive management [is a decision process that] promotes flexible decision making that can be adjusted in the face of uncertainties as outcomes from management actions and other events become better understood. Careful monitoring of these outcomes both advances scientific understanding and helps adjust policies or operations as part of an iterative learning process. Adaptive management also recognizes the importance of natural variability in contributing to ecological resilience and productivity. It is not a `trial and error' process, but rather emphasizes learning while doing. Adaptive management does not represent an end in itself, but rather a means to more effective decisions and enhanced benefits. Its true measure is in how well it helps meet environmental, social, and economic goals, increases scientific knowledge, and reduces tensions among stakeholders. Adaptive management as defined here involves ongoing, real-time learning and knowledge creation, both in a substantive sense and in terms of the adaptive process itself. It is described in what follows in a series of 9 steps, as summarized in section 4.1, involving stakeholder involvement, management objectives, management alternatives, predictive models, monitoring plans, decision making, monitoring responses to management, assessment, and adjustment to management actions. !"TTT0..CVt~Me~~ ~ ASSESS SITUATION ADJUST DESIGN EVALUATE IMPLEMENT MONITOR TH E ADAPTIVE MANAGEMENT PROCESS _ A~~~-I Cost Estimates for Thunderbird Lake Nlannge~ment Options Attachment B ITEM DESCRIPTION COST ESTIMATES Low High Option A - No Action Costs associated with initial set-uplcapital investment Community education & outreach $8,500 $10,000 InitiallCapital Subtotal $8,500 $10,000 LegallAttorney fees Legal Subtotal $0 $0 Annual or on-going costs Maintenance of the the drain $2,000 $4,500 AnnuallOngoing Subtotal $2,000 $4,500 Total Initial Costs for No Action option $10,500 $14,500 Page[Page] Cost Estimates for Thunderbird Lake Nlannge~ment Options Attachment B ITEM DESCRIPTION COST ESTIMATES Low High Option B-Adaptive Management Costs associated with initial set-uplcapital investment Potential projects to be further evaluated Boardwalk Re-assessment of other amenities Re-designing the configuration of the lake Aeration unit or fountain Community education & outreach $8,500 $10,000 Subtotal $8,500 $10,000 LegallAttorney fees Legal Subtotal $0 $0 Annual or on-going costs Contract to add microbes $4,000 $5,000 Solar Bee ®solar panel replacements $1,000 $1,500 Water quality sampling {staff} $1,000 $2,500 Duckweed removal $1,000 $5,000 Tree thinning {staff} $500 $1,000 Re-application for simple wetland permitfor view corridors (every 3 years} $1,500 $3,000 Maintenance of the the drain $2,000 $4,500 AnnuallOn-going Subtotal $11,000 $22,500 Staff OversightlMaintenance {OIM} Estimate $18,000 $20,000 AnnuallOn-going Subtotal with Staff 0IM $29,000 $42,500 Total Initial Costs for Adaptive Management option $37,500 $52,500 Page[Page] Cost Estimates for Thunderbird Lake Nlannge~ment Options Attachment B ITEM DESCRIPTION COST ESTIMATES Low High Option C -Potable Water -one fill per year Costs associated with initial set-up/capital investment Hydrant $0 $0 Community education & outreach $8,500 $10,000 Wetland mitigation on site for addition of water to 2 acres in surface area $20,000 $50,000 Potable water {2008 potable water rate -ranges from 2 to 2.4 acres in surface area -initial fill} $6,500 $15,500 Initial/Gapital5ubtotal $35,000 $75,500 LegallAttorney fees Legal Subtotal $0 $0 Annual or on-going costs Standard wetland permit for addition of water {3 years} $5,000 $8,000 MINDUdischarge permit $1,000 $1,000 Potable water {2008 rate -ranges from 2 to 2.4 acres in surface area -may be more if water loss is higher than estimated} $3,000 $3,500 De-chlorination $2,000 $4,000 Adaptive management practices- subtotal of items listed below $11,000 $22,500 Contract to add microbes $4,000 $5,000 Solar Bee ®solar panel replacements $1,000 $1,500 Water quality sampling (staff} $1,000 $2,500 Duckweed removal $1,000 $5,000 Tree thinning (staff} $500 $1,000 Re-application for simple wetland permit for view corridors {every 3 years} $1,500 $3,000 Maintenance of the the drain $2,000 $4,500 AnnuallOn-going Subtotal $22,000 $39,000 Staff O1M Estimate $20,000 $25,000 AnnuallOn-going Subtotal with Staff OIM $42,000 $64,000 Total Initial Costs for Potable Water option -one fill per year $77,000 $139,x00 Page[Page~ Cost Estimates for Thunderbird Lake Nlannge~ment Options Attachment B ITEM DESCRIPTION COST ESTIMATES Low High Option D -Potable Water -multiple fills per year Costs associated with initial set-up/capital investment Hydrant $0 $0 Community education & outreach $8,500 $10,000 Wetland mitigation on site for addition of water to 2 acres in surface area $20,000 $50,000 Potable water (2008 potable water rate -ranges from 2 to 2.4 acres in surface area -initial fill} $6,500 $15,500 Retro-fit irrigation $5,000 $10,000 InitiallCapital Subtotal $40,000 $85,500 LegallAttorney fees Legal Subtotal $0 $0 Annual or on-going costs Standard wetland permit for addition of water (3 years} $5,000 $8,000 MINDUdischarge permit $1,000 $1,000 Potable water (2008 rate -ranges from 2 to 2.4 acres in surface area -may be more if water loss is higher than estimated} $3,000 $3,500 De-chlorination $4,000 $8,000 Adaptive management practices- subtotal of items listed below $11,000 $22,500 Contract to add microbes $4,000 $5,000 Solar Bee ®solar panel replacements $1,000 $1,500 Water quality sampling {staff? $1,000 $2,500 Duckweed removal $1,000 $5,000 Tree thinning (staff) $500 $1,000 Re-application for simple wetland permit for view corridors (every 3 years} $1,500 $3,000 Maintenance of the the drain $2,000 $4,500 AnnuallOn-going Subtotal $24,000 $43,000 Staff O/M Estimate $25,000 $30,000 AnnuallOn-going Subtotal with Staff OIM $49,000 $73,000 Total Initial Costs for Potable Water option -multiple fills per year $89,000 $158,500 Page[Page] Cost Estimates for Thunderbird Lake Nlannge~ment Options Attachment B ITEM DESCRIPTION COST ESTIMATES Low High Option E -Groundwater Well at 8.5 or 3 gpm Costs associated with initial set-uplcapital investment Community education & outreach $8,500 $10,000 Wetland mitigation on site for addition of water to 2 acres in surtace area $20,000 $50,000 Groundwater monitoring wells (3 to 9} $10,000 $27,000 Hobo data logging units for the monitoring wells {3-9} $2,000 $5,000 MODFLOW analysis/depletions study $10,000 $15,000 Substitute water supply plan/permit fortemporary use $1,500 $3,000 Application fees {such as supply permits, court application, publication fees, etc} $1,500 $3,000 Augmentation planlEngineering $10,000 $35,000 Pumping station {10 acre feet) $55,000 $65,000 Storage facility for augmentation water {10 acre feet- necessary prior to temporary pumping} $50,000 $120,000 Initial/Capital Subtotal $168,500 $333,000 LegallAttorney fees Legal Subtotal $25,000 $100,000 Annual or on-going costs Standard wetland permit for addition of water {3 years} $5,000 $8,000 Water or water rights for augmentation $40,000 $80,000 Adaptive management practices- subtotal of items listed below $11,000 $22,500 Contract to add microbes $4,000 $5,000 Solar Bee ®solar panel replacements $1,000 $1,500 Water quality sampling {staff} $1,000 $2,500 Duckweed removal $1,000 $5,000 Tree thinning (staff} $500 $1,000 Re-application for simple wetland permit for view corridors (every 3 years} $1,500 $3,000 Maintenance of the the drain $2,000 $4,500 AnnuallOn-going Subtotal $56,000 $110,500 Staff O/M Estimate $30,000 $50,000 AnnuallOn-going Subtotal with Staff 0IM $86,000 $160,500 Total Initial Costs for Groundwater Well option 5279,500 $593,500 Page[Page] Cost Estimates for Thunderbird Lake Nlannge~ment Options Attachment B ITEM DESCRIPTION COST ESTIMATES Low High Option F -RetrofittedlLowered Tile Drain Costs associated with initial set-uplcapital investment Community education & outreach $8,500 $10,000 Wetland mitigation on site for addition of water to 2 acres in surtace area $20,000 $50,000 Groundwater monitoring wells (3 to 9} $10,000 $27,000 Hobo data logging units for the monitoring wells {3-9} $2,000 $5,000 MODFLOW analysis/depletions study $10,000 $15,000 Substitute water supply plan/permit fortemporary use $1,500 $3,000 Application fees (such as supply permits, court application, publication fees, etc} $1,500 $3,000 Augmentation planlEngineering $10,000 $35,000 Tile drain construction $165,000 $200,000 Storage facility for augmentation water {10 acre feet- necessary prior to temporary pumping} $50,000 $120,000 Initial/Capital Subtotal $278,500 $468,000 LegallAttorney fees Legal Subtotal $25,000 $100,000 Annual or on-going costs Standard wetland permit for addition of water (3 years} $5,000 $8,000 Water or water rights for augmentation $40,000 $80,000 Adaptive management practices- subtotal of items listed below $11,000 $22,500 Contract to add microbes $4,000 $5,000 Solar Bee ®solar panel replacements $1,000 $1,500 Water quality sampling {staff} $1,000 $2,500 Duckweed removal $1,000 $5,000 Tree thinning (staff} $500 $1,000 Re-application for simple wetland permit for view corridors (every 3 years} $1,500 $3,000 Maintenance of the the drain $2,000 $4,500 AnnuallOn-going Subtotal $56,000 $110,500 Staff O/M Estimate $30,000 $50,000 AnnuallOn-going Subtotal with Staff OIM $86,000 $160,500 Total Initial Costs for RetrofittedlLowered Tile Drain option $389,500 $728,500 Page[Page] Cost Estimates for Thunderbird Lake Nlannge~ment Options Attachment B ITEM DESCRIPTION COST ESTIMATES Low High Option G -Stormwater -assumes that water rights are pursued Costs associated with initial set-uplcapital investment Community education & outreach $8,500 $10,000 Wetland mitigation on site for addition of water to 2 acres in surtace area $150,000 $160,000 Groundwater monitoring wells (3} $10,000 $12,000 Hobo data logging units for the monitoring wells (3} $2,000 $3,000 Analysis $20,000 $50,000 Substitute water supply plan/permitfor temporary use $1,500 $3,000 Application fees (such as supply permits, court application, publication fees, etc} $1,500 $3,000 Augmentation planlEngineering $10,000 $35,000 Stormwater system $45,000 $65,000 InitiallCapital Subtotal $248,500 $341,000 Legal/Attorney fees Legal Subtotal $25,000 $100,000 Annual or on-going costs Standard wetland permit for addition of water (3 years} $5,000 $8,000 Water or water rights for augmentation $40,000 $80,000 Adaptive management practices- subtotal of items listed below $11,000 $22,500 Contract to add microbes $4,000 $5,000 Solar Bee ®solar panel replacements $1,000 $1,500 Water quality sampling (staff} $1,000 $2,500 Duckweed removal $1,000 $5,000 Tree thinning (stafF} $500 $1,000 Re-application for simple wetland permit for view corridors (every 3 years} $1,500 $3,000 Maintenance of the the drain $2,000 $4,500 Annuall0n-going Subtotal $56,000 $110,500 Staff O/M Estimate $30,000 $50,000 AnnuallOn-going Subtotal with Staff OIM $86,000 $160,500 Total Initial Costs for Stormwater option $359,500 $601,500 Page[Page~ Cost Estimates for Thunderbird Lake Nlannge~ment Options Attachment B ITEM DESCRIPTION GOST ESTIMATES Low High Option H -Diversion from Bear Canyon Creek Gosts associated with initial set-uplcapital investment Community education & outreach $8,500 $10,000 Wetland mitigation on site for addition of water to 2 acres in surtace area $20,000 $50,000 Groundwater monitoring wells (3} $10,000 $12,000 Hobo data logging units for the monitoring wells (3} $2,000 $3,000 Historical use/change of use analysis $20,000 $50,000 Substitute water supply planlpermitfortemporary use $1,500 $3,000 Application fees (such as supply permits, court application, publication fees, etc} $1,500 $3,000 Diversion Infrastructure and Easements $280,000 $410,000 InitiallCapital Subtotal $343,500 $541,000 LegallAttorney fees Legal Subtotal $25,000 $100,000 Annual or on-going costs Standard wetland permit for addition of water (3 years} $5,000 $8,000 Water or water rights $40,000 $45,000 Adaptive management practices- subtotal of items listed below $11,000 $22,500 Contract to add microbes $4,000 $5,000 Solar Bee ~ solar panel replacements $1,000 $1,500 Water quality sampling (staff $1,000 $2,500 Duckweed removal $1,000 $5,000 Tree thinning (staff} $500 $1,000 Re-application for simple wetland permit for view corridors (every 3 years} $1,500 $3,000 Maintenance of the the drain $2,000 $4,500 AnnuallOn-going Subtotal $56,000 $75,500 Staff O!M Estimate $30,000 $50,000 AnnuallOn-going Subtotal with Staff O!M $86,000 $125,500 Total Initial Costs for Diversion from Bear Canyon Creek option $454,500 $766,500 Notes: Construction costs do not include city costs to hire and manage contractor. Costs are for the P&R Department only and do not include staff time or ofher costs to ofher departments. Cost estimates are based upon costs for similar projects but are preliminary of this time. The $70, 000 to $12,000 estimate to lower the outlet was removed as the work is in progress. Page[Page] ATTACHMENT C Response to Questions from WRAB Members December 15, 2008 1. Haw much has been spent so far on this project, such as consultants and studies? Response: To date, $115,000 has been spent, not including staff time. 2. Coulcl staff use volunteers or other personnel to lessen the cost of sampling? Response: Possibly, although water sampling costs include the services normally provided by a water quality specialist, which include; - Access to water (which may include boat or special equipment to reach sample areas and sample multiple water depths). - Method to ensure non-contamination of sample (sterile vials, protection from non-source contaminants, temperature control, preservation methods, etc.) - Field calibration of instruments - Weather and site documentation - Laboratory procedure and analysis - Reporting 3. ~'t~hy is a wetland permit required is water is added to Thunderbizd Lake? Response: The city of Boulder has stricter guidelines than state or federal regulations concerning wetland protection. Wetlands in the city of Boulder were updated and mapped in 2004, and the wetland area of Thunderbird Lake was part of those updates. Any modification of wetlands currently requires a wetland permit. 4. Are there any other pre-existing scenarios where water level was raised and wetlands inundated and permits were issued (or not)? Response: No. The example of Boulder Reservoir was raised relevant to fluctuating water levels and effects to nearby wetlands. Boulder Reservoir is part of a water distribution system and according to the city wetland ordinance, is therefore exempt from city of Boulder wetland permit requirements. 5. Can the city waive or exempt a requirement for a wetland permit? Response: In the case of Thunderbird Lake, any action item affecting the existing wetland would require a wetland permit. There would be no waivers or exemptions for this situation. 6. Just how bad would it be to add chlorinated water to the lake environment? Response: State and federal regulations require treatment of chlorinated water before any discharge into the environment. Chlorinated water can have adverse affects to aquatic biota. ATTACHMENT C 7. What techniques are used to de-chloiznate water when hydrants or water lines are flushed? Response: The city uses either tablets or liquid via a de-chlorination chamber as part of the releasei'flushing process to treat the water before it is discharge into the stormwater system. S. What is the incremental cost per gallon to treat water? Response: The city does not have records to specifically determine the exact cost per gallon to treat raw water. Cost include, but are not limited to, water rights, transportation, maintenance, staffing, chemicals and delivery. Extrapolating from 2007 data fiom both treatment facilities (Betasso and 63'~`~ Street): Number of gallons produced: 6.067 billion gallons Operational budget: $4.0 million Approximate cost per 1,000 gallons: $0.65 9. In regards to the Admiral Burke Memorial, was the lake part of the planning process? Response: No, the lake itself was not integral to the memorial planning process. It does enhance the naval theme of the memorial by its presence, but was not taken into consideration as part of the formal planning process. 10. ~Vhat is the irrigation use in the neighborhood currently verses historical? Is the development of the neighborhood contributing to the lower groundwater level issue? Response: The exact usage patterns for this neighborhood regarding irrigation water usage are unknown. V4~ater usage is tracked by total water use per household. The urban development has likely contributed to altering ground«~ater levels as sump pump usage is common in this area to protect homes from seepage. This «~ater is discharge into the stormwater system and not directly back into groundwater system. 11. If neighbors are saving on water use, then couldn't those savings be used to justify adding water to the lake or used to assist in maintaining groundwater levels? Response: The city of Boulder has emphasized water conservation practices ley the city as a whole as a matter of environmental sustainability. The water savings by surrounding residents result in savings to the water delivery system and are not linked to the groundwater system in the area. Any reduction in grater use by residents would not be used to balance increased water use by the Parks and Recreation Department. ATTACHMENT C 12. What are the causes for the lower water table? Response: A detailed report regarding the groundwater, local hydrology, topology, geology and other affecting factors that may be contributing to the lower water table was provided by the consulting firm Biohabitats, Inc. This report was provided to the city in February 2448, Potential Future Management Options fot~ Thunderbit~d Lake. Generally speaking, the drought conditions that were experienced from 2444 - 2443, appear to have had the greatest affect on the local water tables, coupled with the residential urbanization near the Thunderbird Lake area. 13. Would the city be called upon to add treated water to other lakes and ponds in the city that have no other viable source of ditch or untreated water? Response: Possibly, although this would be the first time that the city has been asked to add water to a body of water that is not part of a water delivery system. 14. Is the precedent beuig set to manipulate water levels elsewhere in the city? Response: Yes, this could result in other situations where the city may be asked to affect ~~-~ater levels in areas outside the city's water delivery system. 15. Aie there water rights associated with Thunderbird Lake? Response: Yes. Records indicate that the water right references a flow of 1.2 cubic feet per second. They are not, however, associated with a live stream thus no historical flow records are available. This is further explained in the February 2448 report by Biohabitats, Inc.