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HomeMy WebLinkAboutAgenda - 09-14-2021; 12-2 - Information Item – Memorandum Regarding Administrative Updates to the Eno River Voluntary Water Management Operations Plan (WMOP) 1 ORANGE COUNTY NORTH CAROLINA MEMORANDUM TO: Board of County Commissioners Bonnie Hammersley, Orange County Manager Travis Myren, Orange County Deputy Manager FROM: Christopher J. Sandt, P.E., Staff Engineer Craig N. Benedict, Planning Director DATE: August 30, 2021 SUBJECT: BOCC Information Item —Administrative Updates to the Eno River Voluntary Water Management Operations Plan (WMOP) This purpose of this Information Item is to inform the BOCC of proposed administrative updates to the Eno River Voluntary Water Management Operations Plan (WMOP). Background In 1988, Orange County became party to the Eno River Voluntary Water Management Operations Plan (WMOP). The WMOP was/is intended to preserve a minimum flow in the Eno River, even during times of drought, by restricting the amount of raw water that major water users (i.e. users who withdraw 100,000 gallons of raw water per day or more) can withdraw from the Eno River. The three major water users who are parties to the WMOP are the Town of Hillsborough (Town), Orange-Alamance Water System (OAWS) and Resco Products (formerly Piedmont Minerals). Orange County is party to the WMOP because at the time of the original development of the WMOP, Lake Orange (owned and operated by Orange County) was the only public water supply reservoir located within Orange County that was capable of controlling raw water releases from the dam. In the year 2000, the WMOP was revised/modified to incorporate the West Fork Eno Reservoir (WFER) into the WMOP. The WFER (owned and operated by the Town) is a public water supply reservoir located on the West Fork of the Eno River. The WMOP sets forth a minimum release schedule from both the Lake Orange dam (County-operated) and the West Fork Eno Reservoir dam (Town-operated) to provide the major water users with raw water based on allocations as specified within the WMOP. In addition, the WMOP mandates minimum in-stream flow within the Eno River during dry weather periods to help sustain aquatic ecosystem health. The North Carolina Department of Environmental Quality, Division of Water Resources (DWR) currently administers the WMOP. The Orange County Staff Engineer is responsible for monitoring daily Eno River flows and initiating/rescinding raw water withdrawal restrictions during low-flow (dry weather) periods. The Orange County Staff Engineer reviews raw water release data from Lake Orange, Lake Ben Johnston (a run-of-river dam owned and operated by the Town), Corporation Lake (a run-of-river dam owned and operated by OAWS), and the WFER to monitor established river flow and raw water withdrawal targets as specified in the WMOP. Allocated water withdrawers are responsible for monitoring and reporting their raw water withdrawals to DWR and the Page 1 of 2 2 Orange County Staff Engineer. Additional background information on the Eno River and the WMOP is located at the following DWR website links: http://www.ncwater.org/Eno River Management/ http://www.ncwater.org/Eno River Management/plan.phi) Purpose of Information Item The last revision to the WMOP (the addition of the WFER) was made in 2000, over 20 years ago, and involved regulatory changes that required review and approval by the Environmental Management Commission (EMC) prior to execution. The existing WMOP (i.e. the 2000 version) is in typewritten font and needs to transition to the 21st Century. The existing WMOP does not contain a table of contents or page numbers for reference by the reader, and Resco Products (one of the major water users) is noted erroneously as Piedmont Minerals. In addition, the existing WMOP contains some administrative ambiguities that require minor clarifications and/or refinements. See Attachment 1 for a copy of the existing WMOP. The Orange County Staff Engineer originally initiated the proposed administrative updates with the WMOP partners in early 2020. Since that time, Orange County has received formal consent and input from all WMOP partners, including DWR. The WMOP partners have collectively agreed that it is time to update the formatting of the WMOP and provide more background and explanation of the existing WMOP terms. DWR has confirmed, in writing, that the proposed WMOP updates as contained within this Information Item will not require EMC review or approval due to the administrative/cosmetic nature of the proposed updates. The proposed updates involve converting the late-1980's WMOP document to electronic format, providing a table of contents and page numbers, adding an introductory section, making grammar and editorial updates, and providing a better explanation of the allowable raw water withdrawal allocations (i.e. revisions to Table 1 within the WMOP). The proposed revisions also update the names of the current partners and current state agencies. See Attachment 2 for a copy of the proposed WMOP, inclusive of proposed updates. DWR staff has accepted and integrated all of the requested administrative WMOP updates as such. The Hillsborough Board of Commissioners was made aware of the proposed WMOP updates through a Town staff-initiated information item on consent agenda at their August 9, 2021 meeting; see Agenda/Minutes at the link below: http://archive.hillsboroughnc.gov/WebLink/l/doc/3424/Pagel.aspx. There were no Town Commissioner comments and/or exceptions received. There are no Orange County financial impacts associated with the proposed WMOP updates. NOTE: Any future proposed regulatory/material changes to the WMOP (e.g. changing allocated raw water withdrawals, changing minimum water releases, etc.) would require formal presentation to the WMOP partner government leaders and the EMC for review and approval prior to execution. Please communicate any questions or concerns to Christopher J. Sandt, P.E., Staff Engineer (csandt@orangecountync.gov or 919-245-2583). Page 2 of 2 3 Department of Natural Resources and Community Development Division of Water Resources ENO RIVER CAPACITY USE INVESTIGATION ------------------------------------ G11ATER Y,,ANAGERjENT OPERATIONS PLA14 -------------------------------- August 19 , 1988 Endorsed by Environmental Management Commission September 8 , 1988 Modified March 1989 Revised July 1990 4 WATER MANAGEMENT PLAN All water users in the Eno River Basin who withdraw more than 100 , 000 gallons of water per day from surface water or groundwater sources are subject to the management controls of this plan. Both water withdrawals and reservoir releases are subject to controls. Water users affected by controls under the plan are listed below. 1 . Town of Hillsborough -- Lake Ben Johnston withdrawal and reservoir release. 2 . Orange-Alamance -- Corporation Lake withdrawal and reservoir release. 3 . Piedmont Minerals -- Eno Fiver withdrawal. 4 . City of Durham -- Eno River withdrawal. 5 . West Point Grist Mill -- Eno River. 6 . Irrigators whose monthly average withdrawal exceeds 100 , 000 gallons per day. 7. Orange County -- Releases from Lake Orange, Corporation Lake, and Lake Ben Johnston. 5 The limited capacity of the basin requires these users to be subject to the following controls. Hillsborough Water System The Hillsborough Water System will be allowed to withdraw a maximum of 1 ,510 ,000 gallons of water per day from their intake at Lake Ben Johnston. Maximum allowable withdrawals will change as the lake levels at Lake Orange change . Table 1 indicates the maximum allowable withdrawal at successive storage levels. The Orange-Alamance Water System The Orange-Alamance Water System will be allowed to withdraw a maximum of 820 ,000 gallons of water per day from its intake at Corporation Lake. Allowed withdrawals will be reduced as storage at Lake Orange is reduced. Table 1 indicates the maximum allowable withdrawal for given storage levels at Lake Orange. Piedmont Minerals Piedmont Minerals will be allowed to withdraw a maximum of 900 ,000 gallons of water per day from their intake in the Eno River below Lake Ben Johnston when flows at the Eno Gage are 14 cfs and above. This will be reduced to 430 ,000 gallons per day when flows are between 14 cfs and 4 cfs. Below 4 cfs, the maximum allowable withdrawal will depend on the storage and lake levels in Lake Orange, as shown in Table 1 . 6 Durham Water System The Durham Water System will be allowed to withdraw water from the Eno River below the U.S. 501 Bridge in amounts up to 5 , 000 , 000 gallons of water per day when the flows , as measured at the USGS Eno River gage at Durham, are above 30 cfs from March through May and 10 cfs during other times of the year. Withdrawals will cease when flows fall below these levels. West Point Grist Mill. The West Point Grist Idill is a run-of-river operation. The Mill will be permitted to use water from the Eno for mill power and return it to the river immediately downstream. Irrigators With Average Use Exceeding 100, 000 Gallons/Day Irrigators will be allowed to withdraw up to their maximum monthly use, based on water use figures collected by the Division of Water Resources in 1987 for the severe drought year of 1986 . Current (1986) water use would not be restricted, but increases in existing water use and large new users may be restricted. The short-range objective is to limit the expansion of irrigation acreage and facilities until downstream water supply sources can be improved. Users Withdrawing In Excess of 100 ,000 Gallons Per Day Any users, not previously mentioned, which withdraw more than 100, 000 gallons per day from either ground or surface water sources in the Eno River Basin, upstream of the confluence with the Little River, will be required to agree to limits, but are not now included in this plan. 7 Instream Flow In addition to maximum withdrawal limits set for offstream uses in the Eno River Basin, minimum instream flow requirements are established at the Hillsborough streamflow gage (USGS Streamflow Gage # 02085000) . A minimum of 1 . 7 cfs (1 , 100, 000 gallons per day) is to be maintained at the gage when Lake Orange is greater than 80 percent total storage. This value is reduced as the storage level decreases at Lake Orange. Table 1 lists the minimum instream flow requirements. Orange County will be responsible for coordinating releases and maintaining minimum flows at the gage. The three major withdrawers will provide withdrawal schedules to the County at least one week in advance and will notify the County immediately regarding emergencies and other necessary changes in the withdrawal schedule. Additional Storage The withdrawal allocation can be revised whenever additional storage facilities are completed in the capacity use area or when additional water supplies are made available from sources outside the area. New storage facilities will be reviewed to ensure that there are no adverse effects upon the permit holders or on streamflow as measured at the Hillsborough gage. 8 Outside Sources Water obtained from sources outside of the area designated as capacity use will not be limited under the Eno Capacity Use regulations. During periods of higher flows (over 10 cfs or 6 .452 MGD) , public water supply systems may take additional water from the Eno, provided that they have long-term contracts for obtaining an equal amount of water from outside the basin when the flow in the Eno drops. This type of adjustment will be evaluated on a case-by-case basis by the N.C. Division of Water Resources. Plan Administration Orange County will be responsible for notifying affected water users of levels at Lake Orange and of the reductions of water withdrawals as required by the Plan. Periodic Review and Changes Withdrawal allowances will be subject to review every 5 years or when changes have been made to current systems, storage, or supply sources. Plan Support Technical support, plan clarification, and approval of minor interim adjustments and modifications will be provided by the N.C. Division of Water Resources. 9 Reporting Average daily withdrawal in million gallons per day (MGD) for Orange-Alamance, Hillsborough, and Piedmont Minerals will be reported monthly to the Division of Water Resources. Average daily withdrawals in MGD for agricultural users will be reported annually in March. 10 Revised July 1990 Table 1 Maximum Allowable Surface Water Withdrawals ------------------------------------------- Based_on_Lake-Orange-Level Drawdown Allowable Surface Water Withdrawal Percent of in feet --------gallons per day----------- Storage from top Remaining at of 1-ft . Town of Orange- Piedmont Instream Flow Lake-Orange-__-flashboard-_Hillsborough--Alamance--MineralsRequirement > 100 spilling * * ** 1 , 100, 000 100 - 80 0 . 0 1 , 510,000 820, 000 430, 000 1 , 100, 000 80 - 60 2 . 0 1 , 360, 000 740, 000 380, 000 650, 000 60 - 50 4 . 3 1 , 280 , 000 700, 000 360, 000 450, 000 50 - 40 5 . 8 1 , 280, 000 700, 000 320, 000 450, 000 40 - 30 7 . 4 1 , 130,000 620, 000 190, 000 0 < = 30 9 . 3 680, 000 370, 000 0 0 ------------------------------------------------------------------------ notes: *- Adjusted to reflect outside source agreement for Hillsborough and Orange-Alamance. - Excess withdrawals from Eno River based on outside source agreement may be made when flows at the Eno River at Hillsborough Gage are 10 cubic feet per second (cfs) and above, regardless of water level in Lake Orange. Maximum withdrawals will be limited to the total of the contract amount and the allocated amount. - A low flow period will begin on the 7th consecutive day of the average daily flow at the Hillsborough Gage dropping below 10 cfs. On the 4th day, the Orange County Engineer will request that affected parties prepare for a low flow period. - When flows are between 10 cfs and 3 cfs at the Hillsborough Gage during a low flow period, withdrawals from the Eno River shall be limited to the 100-80 percent of storage remaining amount shown above, regardless of water level in Lake Orange. - When flows are below 3 cfs at the Hillsborough Gage, during a low flow period, withdrawals will be limited to amounts shown above for percent of storage remaining at Lake Orange. - A low flow period will be terminated when average daily flow at the Hillsborough Gage registers 10 cfs or greater for a period of 7 consecutive days. The Orange County Engineer will notify affected parties when the low flow period is terminated. **- For Piedmont Minerals Inc: When flows at the Hillsborough gage are 14 cfs and above, withdrawals from the Eno River will be limited to 9001,000 gallons per day (gpd) . Between 14 cfs and and 4 cfs, withdrawals will be limited to 430,000 gpd, regardless of water level in Lake Orange. Below 4 cfs, withdrawals will be limited to amounts shown above for percent of storage remaining. 11 June 1991 ADDENDUM To the Eno River Voluntary Water Use Agreement When Lake Orange is above 100 percent full and is spilling, Hillsborough will be allowed partial credit for water purchased from an outside source and discharged into the Eno River west of county road 1009 during the monitoring week that the discharge occurs, at a credit rate of 60 percent of the total discharge, when the discharge is made over a 24-hour period or greater. The credit volume will be divided by 7 days and added to the withdrawal limit listed in Table 1, to determine the allowed average daily withdrawal for that week. In the event that the flushing discharge straddles two monitoring weeks, the credit volume will be applied equally between the two weeks. The Orange County Engineer, or DWR staff in his absence, must be notified of the volume and the duration upon completion of the flushing. A written report of the flushing, detailing exact dates, times, and volumes, shall be included in the monthly report to DWR. If notification is not received with that months water use report, no credit will be granted and any excess water use will be labeled as a violation of this agreement . The Division of Water retains the right to revoke permission for Hillsborough to receive credit for flushed flows if at any time , in the opinion of the Division, the ability of Ben Johnston Dam to meet downstream flows may be compromised. Said revocation will be in effect until there is notice by DWR that the problem has been corrected to its satisfaction. If Lake Orange is not spilling, no credit will be allowed. - In the event that flow at the Eno River at Hillsborough streamflow gage is over 10 cfs, Corporation Lake and Lake Ben Johnston are both spilling water over the dams, purchases of water are being made from outside of the Eno River Basin, and the low flow period has not yet ended, users may cease their outside purchase of water and withdraw the amount of water allowed in the absence of a low flow period, as long as the ability to resume purchase of water for immediate customer delivery remains. This time period has been determined to be three days for the OWASA line. Water purchases will be made as often as necessary to flush the lines and keep them from stagnating. If flows drop below 10 cfs before the low flow period is over, Eno River withdrawals must immediately be reduced to Table 1 levels. - Transfer of water allocation between users is permissible under the following conditions: 1) Lake Orange is greater than 80 percent full; 2) notification of the duration and specific volume of the transfer will be given by the surrendering party to the Orange County Engineer, or the DWR in his absence, a minimum of one day before the transfer is to take place; 3) the total allocation will be adjusted if necessary by the averaging period of the surrendering party, and 4) written notification of the duration and volume of the transfer will be provided by both involved parties in their monthly water use reports to DWR. If prior notification is not received, DWR will not recognize the allocation transfer. 12 Eno River Water Management Plan Table 1 Revised March 2000 Maximum Allowable Surface Water Withdrawals Based on Lake Orange Water Level Allowable Surface Water Withdrawal Instream Flow Requirement at Hillsborough Gage Percent of (gallons per day) (gallons per day) Storage Drawdown Remaining in feet from From Total Flow at at Lake top of 1-ft. Town of Orange- Piedmont From West Fork Eno Hillsborough Orange flashboard Hillsborough+ Alamance Minerals Lake Orange Reservoir Gage > 100 spilling *t * "* 1,100,000 650,000 1,750,000 Stage 1 100 - 80 0.0 1,510,000t 820,000 430,000 1,100,000 650,000 1,750,000 Stage 2 80 -60 2.0 1,360,000t 740,000 380,000 650,000 650,000 1,300,000 Stage 3 60 - 50 4.3 1,280,000t 700,000 360,000 450,000 650,000 1,100,000 Stage 4 50 -40 5.8 1,280,000t 700,000 320,000 450,000 650,000 1,100,000 Stage 5 40 - 30 7.4 1,130,000t 620,000 190,000 0 650,000 650,000 Stage 6 �= 30 9.3 680,000' 370,000 0 0 650,000 650,000 Notes: + Allowable withdrawals for Hillsborough shown above do not include withdrawals of water supply releases from West Fork Eno Reservoir. * - Adjusted to reflect outside source agreement for Hillsborough and Orange-Alamance. - Excess withdrawals from Eno River based on outside source agreement may be made when flows at the Eno River at Hillsborough Gage are 10 cubic feet per second(cfs) and above,regardless of water level in Lake Orange. Maximum withdrawals shall be limited to the total of the contract amount and the allocated amount. - A low flow period will begin on the 7`'consecutive day of the average daily flow at the Hillsborough Gage dropping below 10 cfs. On the 4`i'day, the Orange County Engineer will request that affected parties prepare for a low flow period. - When flows are between 10 cfs and 3 cfs at the Hillsborough Gage during a low flow period,withdrawals from the Eno River shall be limited to the Stage 1 amount shown above (100-80 percent of storage remaining), regardless of water level in Lake Orange. - When flows are below 3 cfs at the Hillsborough Gage during a low flow period, withdrawals shall be limited to amounts shown above for percent of storage remaining at Lake Orange. - A low flow period will be terminated when average daily flow at the Hillsborough Gage registers 10 cfs or greater for a period of 7 consecutive days. The Orange County Engineer will notify affected parties when the low flow period is terminated. "For Piedmont Minerals: When flows at the Hillsborough Gage are 14 cfs and above,withdrawals from the Eno River will be limited to 900,000 gallons per day(gpd). Between 14 cfs and 4 cfs, withdrawals will be limited to 430,000 gpd,regardless of water level in Lake Orange. Below 4 cfs, withdrawals will be limited to amounts shown above for percent of storage remaining. 13 RESOLUTION NO. 88--13 ENVIRONMENTAL MANAGEMENT COMMISSION WHEREAS, at the direction of the Environmental Management Commission (EMC) , the Department of Natural Resources and Community Development has completed a capacity use investigation of the Eno River portion of the Neuse River Basin, pursuant to the provisions of the N.C. Water Use Act ❑f 1967 (G.S. 143-215. 11 et.seq. ) . WHEREAS, the Department found that: 1 . The aggregate use of surface water from the Eno River has grown to the point where coordination is required to prevent conflicts and t❑ protect the interests and rights of riparian owners. 2. During low flow periods the demand for water exceeds the amount of water available from the En❑ River. 3. Limited regulation of water users appears to be an equitable short-term alternative until new water supply sources are developed. 4 . A means is needed to encourage cooperation and conservation among all water users in order that greater efficiencies in water use are promptly implemented. 5. The rapid present and projected growth of water use in the En❑ Basin requires action soon to avoid the risk ❑f even more severe water supply problems. WHEREAS, the Department recommended that the estimated 150 square miles of the Eno River watershed area upstream from the confluence with the Little River be designated as a capacity use area. WHEREAS, the Department developed a proposed water management plan for the Eno Basin to illustrate the types of regulations and permits that would be proposed under the capacity use designation. WHEREAS, the water users in the Eno Basin have committed themselves to follow the proposed water management plan. WHEREAS, the voluntary water management plan includes the essential elements of a declared capacity use area with the exception of the provisions for enforcement. WHEREAS, the General Statute directs the Department to present "actions which might preclude the need for additional regulation. " 14 WHEREAS, the voluntary plan, if adhered to by those involved, satisfactorily addresses the capacity use-related problems in the Eno River area. NOW THEREFORE, BE IT RESOLVED that the EMC accepts the Eno River Capacity Use Investigation Hearing Officer ' s Report and endorses the voluntary Water Management Operations Plan and directs the staff of the Division -of Water Resources to monitor compliance with the plan and make periodic reports to the EMC. BE IT FURTHER RESOLVED, that should the plan not be adhered to by those involved, that the EMC intends to proceed with a designation of capacity use for the Eno River area, as outlined in the Department' s report. This the 8th day of September 1988 . r Charles L. BzfIer Chairman, Environmental Management Commission 15 Department of Environmental Quality (formerly, Department of Natural Resources and Community Development) Division of Water Resources ENO RIVER CAPACITY USE INVESTIGATION WATER MANAGEMENT OPERATIONS PLAN August 19, 1988 Endorsed by Environmental Management Commission September 8, 1988 Modified or Revised: March 1989, July 1990, March 2000, and July 2021 2 16 Table of Contents INTRODUCTION................................................................................................................. 4 Background ................................................................................................................................4 HillsboroughWater System ........................................................................................................6 Orange-Alamance Water System ................................................................................................6 Resco Products (formerly, Piedmont Minerals)...........................................................................6 Cityof Durham Water System.....................................................................................................6 WestPoint Grist Mill...................................................................................................................6 Irrigators with Average Use Exceeding 100,000 Gallons/Day.......................................................6 Users Withdrawing in Excess of 100,000 Gallons Per Day............................................................6 FLOW AND STORAGE REQUIREMENTS............................................................................... 7 InstreamFlow.............................................................................................................................7 AdditionalStorage......................................................................................................................7 OutsideSources..........................................................................................................................7 PLAN ADMINISTRATION.................................................................................................... 7 Periodic Review and Changes......................................................................................................7 PlanSupport...............................................................................................................................7 Reporting....................................................................................................................................8 Addendum 1 —Hillsborough Water Purchases (June 1991).................................................. 9 Table 1 —Eno River Water Management and Operations Conditions(revised October 2020) ........................................................................................................................................ 10 Appendix A: EMC Resolution............................................................................................ 12 Appendix 8: Original Table 1 (July 1990).......................................................................... 14 3 17 INTRODUCTION The Water Management Operations Plan (WMOP) was the result of a Capacity Use Investigation (CUI) by the Department of Environmental Quality(DEQ) (formerly, Department of Natural Resources and Community Development)—Division of Water Resources (DWR) and a subsequent cooperative effort by the DWR and primary water users at the time to avoid a formal Capacity Use designation and regulations. The WMOP, instead, established voluntary water use restrictions that provide for equitable use of the water resources, while providing for minimum flows in the Eno River. The requirements in the WMOP are managed and administered by the water users and Orange County, with oversight and coordination by DWR. The DWR is responsible for production of the quarterly and annual reports based on available information and organization of an annual meeting of the water users group. Based upon the EMC Resolution (attached), the intent of the WMOP is to institute a "voluntary water management plan [that] includes the essential elements of a declared capacity use area with the exception of the provisions for enforcement, ... [to] satisfactorily address the capacity use-related problems in the Eno River area." The specific changes or additions made for each of the previous modifications or revisions listed on the cover page (March 1989, July 1990, March 2000) are not entirely known. However, the changes made in July 1990 and March 2000 included revisions to Table 1. Both versions of Table 1 are included in this current version of the WMOP.The March 2000 revision of Table 1 was specifically concerned with integrating the minimum release requirements for the newly constructed West Fork Eno River Reservoir (WFER). These minimum release requirements were from federal and state permits (Clean Water Act - Sections 401/404, and NCDEMLR Dam Safety Permit) for the dam construction and established outside of requirements by the EMC related to the Eno River WMOP. This revision is limited to editorial changes for clarifications, background information, intent statement based on the EMC Resolution, and to create a modern digital version. This revision in no way implies any management or operational changes to the WMOP. Issues with using the Eno River as a dependable water supply had been documented for many years, dating back to the 1950's, especially during times of drought. As a result, the Orange County Board of Commissioners formed a water resource task force in the early 1980's to study potential options available to improve the situation, who issued a report of their findings in May 1981. According to the Capacity Use Investigation (CUI), issued December 1988, by the DEQ, "The [task force] report discussed possible designation of the Upper Neuse Basin as a Capacity Use Area; concerns over maintaining instream flow needs; water supply limitations; water conservation; potential reservoir sites; and other related items.The County has worked closely with the State in attempting to achieve their water resource objectives." The CUI continues describing the findings from the task force report, "The State has worked closely with the local governments in the Eno River Area in attempting to provide for adequate water supplies and minimum instream flow needs. The State has assisted local water supply interests in determining storage volumes available in the three reservoirs [i.e, 4 18 Lake Ben Johnson, Corporation Lake and Lake Orange], developing and improving system operating rules, and assisting the County in preparing a draft water conservation ordinance." Several years later, as documented in the CUI, "at the request of the [Orange] County Manager, a simulation was conducted reflecting water demands for Hillsborough and Orange- Alamance as they existed in June of 1986." The results of this modeling concluded that "with the projected water demands in the early 1990's the Eno River would cease to flow at the water intakes ten times and the systems would be in crisis mandatory rationing thirty-two times (a total of 1,830 days). The CUI goes on to say, that "even under existing water supply demands, the potential for a water supply disaster is imminent." Orange County is not one of the six water users, listed below, directly affected by controls under the WMOP, because Orange County does not withdrawal water from the Eno River, as it does not operate a water system or other water withdrawal purpose. However, as the owner of Lake Orange, the County is responsible for the management and operations of Lake Orange to meet specified flow targets in the Eno River through the release of water from Lake Orange. This WMOP establishes the three existing reservoirs as the means by which required minimum flows in the Eno River are controlled; however, with Lake Orange the largest and most upstream, at the time of the issuance of the WMOP, it serves as the primary controlled water source (i.e., reservoir) to meet flow targets in the Eno River downstream during low flows. All water users in the Eno River Basin who withdraw more than 100,000 gallons of water per day from surface water or groundwater sources are subject to the management controls of this plan. Both water withdrawals and reservoir releases are subject to controls. Water users affected by controls under the plan are listed below. 1. Town of Hillsborough -- Lake Ben Johnston and West Fork Eno River Reservoir withdrawal and reservoir releases. 2. Orange-Alamance -- Corporation Lake withdrawal and reservoir releases. 3. Resco Products (formerly, Piedmont Minerals) -- Eno River withdrawal. 4. City of Durham -- Eno River withdrawal. 5. West Point Grist Mill -- Eno River. 6. Irrigators whose monthly average withdrawal exceeds 100,000 gallons per day. The limited capacity of the basin requires these users to be subject to the following controls. 5 19 Hillsborough Water System The Hillsborough Water System will be allowed to withdraw a maximum of 1,510,000 gallons of water per day from their intake at Lake Ben Johnston. Maximum allowable withdrawals will change as the lake levels at Lake Orange change.Table 1 indicates the maximum allowable withdrawal at successive storage levels. Orange-Alamance Water System The Orange-Alamance Water System will be allowed to withdraw a maximum of 820,000 gallons of water per day from its intake at Corporation Lake. Allowed withdrawals will be reduced as storage at Lake Orange is reduced. Table 1 indicates the maximum allowable withdrawal for given storage levels at Lake Orange. Resco Products (formerly, Piedmont Minerals Resco Products will be allowed to withdraw a maximum of 900,000 gallons of water per day from their intake in the Eno River below Lake Ben Johnston when flows at the Eno gage are 14 cfs and above. This will be reduced to 430,000 gallons per day when flows are between 14 cfs and 4 cfs. Below 4 cfs, the maximum allowable withdrawal will depend on the storage and lake levels in Lake Orange, as shown in Table 1. City of Durham Water System The City of Durham Water System will be allowed to withdraw water from the Eno River below the U.S. 501 Bridge in amounts up to 5,000,000 gallons of water per day when the flows, as measured at the USGS Eno River gage at Durham, are above 30 cfs from March through May and 10 cfs during other times of the year. Withdrawals will cease when flows fall below these levels. West Point Grist Mill The West Point Grist Mill is a run-of-river operation. The Mill will be permitted to use water from the Eno for mill power and return it to the river immediately downstream. Irrigators with Average Use Exceeding 100,000 Gallons/Day Irrigators will be allowed to withdraw up to their maximum monthly use, based on water use figures collected by the Division of Water Resources in 1987 for the severe drought year of 1986. Current (1986) water use would not be restricted, but increases in existing water use and large new users may be restricted. The short-range objective is to limit the expansion of irrigation acreage and facilities until downstream water supply sources can be improved. Users Withdrawing in Excess of 100,000 Gallons Per Day Any users, not previously mentioned, which withdraw more than 100,000 gallons per day from either ground or surface water sources in the Eno River Basin, upstream of the confluence with the Little River, will be required to agree to limits, but are not now included in this plan. 6 20 FLOW AND STORAGE REQUIREMENTS Instream Flow In addition to maximum withdrawal limits set for offstream uses in the Eno River Basin, minimum instream flow requirements are established at the Hillsborough streamflow gage (USGS Streamflow Gage #02085000). A minimum of 1.7 cfs (1,100,000 gallons per day) is to be maintained at the gage when Lake Orange is greater than 80 percent total storage. This value is reduced as the storage level decreases at Lake Orange. Table 1 lists the minimum instream flow requirements. Orange County will be responsible for coordinating releases to maintain minimum flows at the gage. The three major withdrawers will provide withdrawal schedules to the County at least one week in advance and will notify the County immediately regarding emergencies and other necessary changes in the withdrawal schedule. Additional Storage The withdrawal allocation can be revised whenever additional storage facilities are completed in the capacity use area or when additional water supplies are made available from sources outside the area. New storage facilities will be reviewed to ensure that there are no adverse effects upon the permit holders or on streamflow as measured at the Hillsborough gage. Outside Sources Water obtained from sources outside of the area designated as capacity use will not be limited under the Eno Capacity Use regulations. During periods of higher flows (over 10 cfs or 6.452 MGD), public water supply systems may take additional water from the Eno, provided that they have long-term contracts for obtaining an equal amount of water from outside the basin when the flow in the Eno drops. This type of adjustment will be evaluated on a case-by-case basis by the N.C. Division of Water Resources. PLAN ADMINISTRATION Orange County will be responsible for notifying affected water users of levels at Lake Orange and the West Fork Eno Reservoir and of the reductions of water withdrawals as required by the Plan. Periodic Review and Changes Withdrawal allowances will be subject to review when changes have been made to current systems, storage, or supply sources. Plan Support Technical support, plan clarification, and approval of minor interim adjustments and modifications will be provided by the N.C. Division of Water Resources. 7 21 Reporting Average daily withdrawal in million gallons per day (MGD) for Orange-Alamance, Hillsborough, and Piedmont Minerals will be reported monthly to the Division of Water Resources. Average daily withdrawals in MGD for agricultural users will be reported annually in March. Additional detailed information regarding the management of water releases and withdrawals, including contact information for membership of the water users group is available at, http://www.ncwater.org/Eno River Management/ 8 22 Addendum 1 -Hillsborough Water Purchases (June 1991) To the Eno River Voluntary Water Use Agreement When Lake Orange is above 100 percent full and is spilling, Hillsborough will be allowed partial credit for water purchased from an outside source and discharged into the Eno River west of county road 1009 during the monitoring week that the discharge occurs, at a credit rate of 60 percent of the total discharge,when the discharge is made over a 24-hour period or greater.The credit volume will be divided by 7 days and added to the withdrawal limit listed in Table 1,to determine the allowed average daily withdrawal for that week. In the event that the flushing discharge straddles two monitoring weeks,the credit volume will be applied equally between the two weeks. The Orange County Engineer, or DWR staff in his absence, must be notified of the volume and the duration upon completion of the flushing. A written report of the flushing, detailing exact dates,times, and volumes, shall be included in the monthly report to DWR. If notification is not received with that month's water use report, no credit will be granted, and any excess water use will be labeled as a violation of this agreement. The Division of Water retains the right to revoke permission for Hillsborough to receive credit for flushed flows if at any time, in the opinion of the Division,the ability of Ben Johnston Dam to meet downstream flows may be compromised. Said revocation will be in effect until there is notice by DWR that the problem has been corrected to its satisfaction. If Lake Orange is not spilling, no credit will be allowed. -In the event that flow at the Eno River at Hillsborough streamflow gage is over 10 cfs, Corporation Lake and Lake Ben Johnston are both spilling water over the dams, purchases of water are being made from outside of the Eno River Basin, and the low flow period has not yet ended, users may cease their outside purchase of water and withdraw the amount of water allowed in the absence of a low flow period, as long as the ability to resume purchase of water for immediate customer delivery remains. This time period has been determined to be three days for the OWASA line. Water purchases will be made as often as necessary to flush the lines and keep them from stagnating. If flows drop below 10 cfs before the low flow period is over, Eno River withdrawals must immediately be reduced to Table 1 levels. -Transfer of water allocation between users is permissible under the following conditions: 1) Lake Orange is greater than 80 percent full; 2) notification of the duration and specific volume of the transfer will be given by the surrendering party to the Orange County Engineer, or the DWR in his absence, a minimum of one day before the transfer is to take place; 3)the total allocation will be adjusted if necessary by the averaging period of the surrendering party, and 4)written notification of the duration and volume of the transfer will be provided by both involved parties in their monthly water use reports to DWR. If prior notification is not received, DWR will not recognize the allocation transfer. 9 23 Eno River Water Management Plan Table 1 - Eno River Water Management and Operations Conditions (revised October 2020) Triggers Allowable Surface Water Withdrawal Minimum Releases West Fork Instantaneous Percent of Drawdown in Eno Instream Flow Storage Lake Orange Town of Orange- Resco Reservoir Requirement at Remaining in from top of Hillsborough Alamance Products Lake Orange (WFER)(mgd Hillsborough Stage Lake Orange flashboard (ft) (mgd [cfs]) (mgd [cfs]) (mgd [cfs]) (mgd [cfs]) [cfs]) Gage(mgd [cfs]) no stage >100 spilling * * 0.9 [1.4] 1.1 [1.7] 0.65 [1.01] Stage 1 100-80 0 1.51 [2.34] 0.82 [1.27] 0.43 [0.67] 1.1 [1.7] 0.65 [1.01] 1.75 [2.71] Stage 2 80-60 2.0 1.36 [2.10] 0.74[1.15] 0.38 [0.59] 0.65 [1.01] 0.65 [1.01] 1.3 [2.01] Stage 3 60-50 4.3 1.28 [1.98] 0.7 [1.08] 0.36 [0.56] 0.45 [0.7] 0.65 [1.01] 1.1 [1.7] Stage 4 50-40 5.8 1.28 [1.98] 0.7 [1.08] 0.32 [0.5] 0.45 [0.7] 0.65 [1.01] 1.1 [1.7] Stage 5 40-30 7.4 1.13 [1.75] 0.62 [0.96] 0.19 [0.29] 0 0.65 [1.01] j 0.65 [1.01] Stage 6 <30 9.3 ir 0.68 [1.05] 0.19 [0.29] 0 0 0.65 [1.01] 0.65 [1.01] million gallons per day(mgd);cubic feet per second(cfs);feet(ft) *When flows are greater than 10 cfs as measured at the Hillsborough gage,additional withdraws beyond those allowed in Table 1 can commence at rates less than or equal to that of contracts held by the Town of Hillsborough &Orange-Alamance for water supply sources outside the basin. Low Flow Stage Conditions: -A low flow period will begin at the end of the 7th consecutive day when the average daily flow at the Hillsborough gage has been below 10 cfs.At the end of the 4th day,the Orange County Engineer will request that affected parties prepare for a low flow period. -When flows are between 10 cfs and 3 cfs at the Hillsborough gage during a low flow period,withdrawals from the Eno River shall be limited to the Stage 1 amount shown above(100-80 percent of storage remaining), regardless of water level in Lake Orange. -When flows are below 3 cfs at the Hillsborough gage during a low flow period,withdrawals shall be limited to amounts shown above for percent of storage remaining at Lake Orange. -A low flow period will be terminated when average daily flow at the Hillsborough gage registers 10 cfs or greater for a period of 7 consecutive days. The Orange County Engineer will notify affected parties when the low flow period is terminated. 10 24 -The Orange County Engineer will notify the affected parties when moving between Low Flow Stages. Conditions for All Water Users: -Allowable withdrawal values are based on natural flow estimates and releases from Lake Orange. -Excess withdrawals from the Eno River based on an outside source agreement may be made when flows at the Hillsborough gage are 10 cfs and above, regardless of water level in Lake Orange. Maximum withdrawals shall be limited to the total of the contract amount and the allocated amount. Conditions for the Town of Hillsborough: -Allowable withdrawals for the Town of Hillsborough shown above do not include withdrawals of water supply releases from the WFER. -Minimum releases from the WFER are based on Army Corps of Engineers Permit Condition, not the Eno River Water Management and Operations Plan. -Releases from Lake Orange and/or the WFER may need to exceed the minimum releases shown in Table 1 to meet the minimum instream flow requirements as shown in Table 1 due to natural conditions. Conditions for Orange County: -Releases from Lake Orange and/or the WFER may need to exceed the minimum releases shown in Table 1 to meet the minimum instream flow requirements as shown in Table 1 due to natural conditions. Conditions for Resco Products: When flows at the Hillsborough gage are 14 cfs and above,withdrawals from the Eno River will be limited to 0.9 mgd. Between 14 cfs and 4 cfs, withdrawals will be limited to 0.43 mgd, regardless of water level in Lake Orange. Below 4 cfs,withdrawals will be limited to amounts shown above for percent of storage remaining. 11 25 Appendix A: EMC Resolution RESOLUTION NO. 88-13 ENVIRONMENTAL MANAGEMENT COMMISSION WHEREAS, at the direction of the Environmental Management Commission (EMC) , the Department of Natural Resources and Community Development has completed a capacity use investigation of the Eno River portion of the Neuse River Basin, pursuant to the provisions of the N.C. Water Use Act of 1967 (G.S. 143-215. 11 et. seq. ) . WHEREAS, the Department found that: 1 . The aggregate use of surface water from the Eno River has grown to the point where coordination is required to prevent conflicts and to protect the interests and rights of riparian owners . 2 . During low flow periods the demand for water exceeds the amount of water available from the Eno River. 3. Limited regulation of water users appears to be an equitable short-term alternative until new water supply sources are developed. 4 . A means is needed to encourage cooperation and conservation among all water users in order that greater efficiencies in water use are promptly implemented. 5. The rapid present and projected growth of water use in the Eno Basin requires action soon to avoid the risk of even more severe water supply problems. WHEREAS, the Department recommended that the estimated 150 square miles of the Eno River watershed area upstream from the confluence with the Little River be designated as a capacity use area. WHEREAS, the Department developed a proposed water management plan for the Eno Basin to illustrate the types of regulations and permits that would be proposed under the capacity use designation. WHEREAS, the water users in the Eno Basin have committed themselves to follow the proposed water management plan. WHEREAS, the voluntary water management plan includes the essential elements of a declared capacity use area with the exception of the provisions for enforcement. 12 26 WHEREAS, the General Statute directs the Department to present "actions which might preclude the need for additional regulation. " WHEREAS, the voluntary plan, if adhered to by those involved, satisfactorily addresses the capacity use-related problems in the Eno River area. NOW THEREFORE, BE IT RESOLVED that the EMC accepts the Eno River Capacity Use Investigation Hearing Officer' s Report and endorses the voluntary Water Management Operations Plan and directs the staff of the Division of Water Resources to monitor compliance with the plan and make periodic reports to the EMC. BE IT FURTHER RESOLVED, that should the plan not be adhered to by those involved, that the EMC intends to proceed with a designation of capacity use for the Eno River area, as outlined in the Department' s report. This the 8th day of September 1988 . Charles L. Baker Chairman, Environmental Management Commission 13 27 Appendix B: Original Table 1 (July 1990) 14 28 Eno River Water Management Plan Table 1 Revised March 2000 Maximum Allowable Surface Water Withdrawals Based on Lake Orange Water Level Allowable Surface Water Withdrawal Instream Flow Requirement at Hillsborough Gage Percent of (gallons per day) (gallons per day) Storage Drawdown Remaining in feet from From Total Flow at at Lake top of 1-ft. Town of Orange- Piedmont From West Fork Eno Hillsborough Orange flashboard Hillsborought Alamance Minerals Lake Orange Reservoir Gage > 100 spilling *t * ** 1,100,000 650,000 1,750,000 Stage 1 100 - 80 0.0 1,510,000t 820,000 430,000 1,100,000 650,000 1,750,000 Stage 2 80 -60 2.0 1,360,000t 740,000 380,000 650,000 650,000 1,300,000 Stage 3 60 - 50 4.3 1,280,000' 700,000 360,000 450,000 650,000 1,100,000 Stage 4 50 -40 5.8 1,280,000' 700,000 320,000 450,000 650,000 1,100,000 Stage 5 40 - 30 7.4 1,130,000t 620,000 190,000 0 650,000 650,000 Stage 6 <=30 9.3 680,000t 370,000 0 0 650,000 650,000 Notes: t Allowable withdrawals for Hillsborough shown above do not include withdrawals of water supply releases from West Fork Eno Reservoir. * - Adjusted to reflect outside source agreement for Hillsborough and Orange-Alamance. - Excess withdrawals from Eno River based on outside source agreement may be made when flows at the Eno River at Hillsborough Gage are 10 cubic feet per second(cfs)and above,regardless of water level in Lake Orange. Maximum withdrawals shall be limited to the total of the contract amount and the allocated amount. - A low flow period will begin on the 7"'consecutive day of the average daily flow at the Hillsborough Gage dropping below 10 cfs. On the 4"'day, the Orange County Engineer will request that affected parties prepare for a low flow period. - When flows are between 10 cfs and 3 cfs at the Hillsborough Gage during a low flow period,withdrawals from the Eno River shall be limited to the Stage 1 amount shown above (100-80 percent of storage remaining),regardless of water level in Lake Orange. - When flows are below 3 cfs at the Hillsborough Gage during a low flow period,withdrawals shall be limited to amounts shown above for percent of storage remaining at Lake Orange. - A low flow period will be terminated when average daily flow at the Hillsborough Gage registers 10 cfs or greater for a period of 7 consecutive days. The Orange County Engineer will notify affected parties when the low flow period is terminated. **For Piedmont Minerals: When flows at the Hillsborough Gage are 14 cfs and above,withdrawals from the Eno River will be limited to 900,000 gallons per day(gpd). Between 14 cfs and 4 cfs, withdrawals will be limited to 430,000 gpd,regardless of water level in Lake Orange. Below 4 cfs, withdrawals will be limited to amounts shown above for percent of storage remaining.