TM - CHEOPS Modeling NC-DWR_3-1-2013_REV1

C-W Water Supply Master Plan 1 February, 2013
Technical Memorandum – NC DWR Coordination

Technical Memorandum-REV1
PROJECT: Catawba-Wateree River Basin Water Supply Master Plan
DATE: Revised March 1, 2013
SUBJECT: CHEOPS Modeling Coordination with NC-DWR

1.0 Introduction
On behalf of the Catawba-Wateree Water Management Group (CWWMG), HDR has initiated
discussions with the North Carolina Division of Water Resources (NC-DWR) regarding
upcoming modeling efforts in the Catawba-Wateree River Basin using CHEOPSTM for the
CWWMG’s Water Supply Master Planning efforts. NC-DWR is providing $400,000 of financial
support to this project, subject to the modeling effort conforming to DWR’s basin modeling
requirements and in conformance with Session Law SL2010-143 and the December 3, 2010
Settlement Agreement South Carolina v. North Carolina, No 138, Orig. (Agreement). The
purpose of prior discussions has been for HDR’s modeling staff to fully understand the NC-
DWR’s expectations as we prepare to move ahead with the Water Supply Master Plan
development.
By way of background, the two major drivers of NC-DWR’s interest in these modeling efforts is
Session Law SL2010-143 and the Agreement. This SL2010-143 is an act to direct the North
Carolina Department of Environment and Natural Resources (NC-DENR) to develop basin-wide
hydrologic models, and requires model approval by the Environmental Management Commission
(EMC). The CWWMG and NC-DWR wish to ensure that by investing in an update of the
CHEOPS model, it will meet the requirements of the Agreement, SL2010-143, is approved by the
EMC and meets the obligations agreed to in the Agreement.
The EMC has required NC-DWR to have an open public/stakeholder process in development and
implementation of basin hydrologic models, which includes making the model available for
public use, provide user training, ensuring ease of functionality and user interface of the model,
and producing sound water use projections.
This Technical Memorandum serves to document the requests of NC-DWR related to CHEOPS
model updates and refinement, the correspondence, understandings and agreements made to-date
concerning these efforts, and estimated implementation schedules for such efforts.
Correspondence to-date regarding this subject has included emails, phone conversations and in-
person meetings between NC-DWR and HDR/CWWMG during 2012 and early 2013.
C-W Water Supply Master Plan 2 February, 2013
Technical Memorandum – NC DWR Coordination

2.0 Water Use Projection and CHEOPS Model Development
2.1 OBJECTIVE
The objective of this effort is to update and refine the CHEOPS model for the Catawba-Wateree
River Basin to comply with the Agreement and SL2010-143 requirements, provide ease of
functionality for NC-DWR and other Catawba stakeholders, execute the scope of work for the
CWWMG and secure approval from the EMC.
2.2 ITEMS INCLUDED
Specific items for CHEOPS model enhancement and water use projection methodology updates
that have been requested by NC-DWR to achieve this objective are provided on the attached
summary spreadsheet. The attached document provides specific details of each of these model
enhancement items, as well as key understandings and general comments, and other
considerations of these tasks.
To guide the implementation of the specific items outlined in the summary spreadsheet, HDR will
hold monthly teleconferences with a project Modeling Technical Team (MTT) to discuss
projection refinement and model development items to facilitate progression of the modeling
effort. The MTT will consist of NC-DWR representatives, HDR project management and
modeling staff (representing CWWMG members), South Carolina Department of Natural
Resources (SCDNR) representatives and potentially representatives from the SC Department of
Health and Environmental Control (SCDHEC) representatives. An invitation was extended to
SCDHEC to participate in the MTT, which they have declined at the present time due to staffing
constraints. They did, however, express that they may potentially participate at a later date if
their staffing situation allows.
UPDATED 2-27-2013Catawba‐Wateree CHEOPS Model Development ‐ HDR Responses to NC‐DWR RequestsItem # Functionality Impact to ResultsKey Actions & Understandings Comments Will Incorporate?1Update base model to '.net' format (enhanced response time)Significant Time series data stored in HEC‐DSS format for OASIS/CHEOPS compatabilityThis function will provide improved model operator efficiency and processing time.100,000 gpd limit to be based on current and 50‐year planning horizonNC DWR to provide HDR with example schematic of these entitities.  HDR to provide NC‐DWR (Don Rayno and Neela Sarwar) with GIS database of existing nodes for Catawba‐Wateree.Withdrawals and discharges to be modeled as a system (i.e. as withdrawals increase, the discharges increase accordingly) based on a monthly factorHDR will provide this functionaility through pre‐processor spreadsheet input.Water shortage responses plans or drought protocols for each system need to be included in the model, with ability to adjust parameters HDR to evaluate WSRP's and compare with LIP that is currently programmed into CHEOPS to determine additional needs.?Must be completed chronologically with 100,000 gpd node functionality as some functionality required is included in that cost estimate.Includes tools needed to update inflow records for all nodesCHEOPS software will be supplied at no additional cost to North and South Carolina.Software will be able to run on a Citrix Server with multiple user access.NCDWR has agreed to allow South Carolina to temporarily use NC's Citrix Server until SC estabilishes its own hosting system.All data to be used is publicly available for review. This request for additional functionality is not relevant as all data in model is visible to the user as it has been historically.N/AA universal demand multiplier (spreadsheet) will be provided only for public water supply withdrawals and returns.HDR will provide this funtionaility through pre‐processor spreadsheet input.A universal on/off switch is needed for water shortage response plans.  For the LIP, then this is a user input that is already part of the model.  For WSRPs on new tributary nodes, this functionality will need to be added to the model, dependant upon how WSRPs are treated (to be determined after evaluation of plans).?Agricultural demands will be aggregated sub‐basin demands based on rainfall and crop E‐T curves.  Or so other approach approve d by DWR that varies water consumption for agricultural use based on climatic conditions during the growing season over the model recordCurrent methodology used is the best to date for Catawba‐Wateree projection development; HDR will provide explanation of current methodology used and will develop a seasonal adjustment factor methodology for application to agricultural irrigation projection.Model documentation to include "User's Manual"User's Manual is currently provided for CHEOPS model.Detailed documentation for DWR staff to be able to update inflows, add nodes, modify water shortage response plans, etc. Such functionality cannot be provided in the model programming, but can be performed through a separate "preprocessor" spreadsheet that is subsequently loaded into the CHEOPS model.Needs to be a minimum of 1 training session open to anyone who wants to learn how to use the model.  Copies of training materials need to be supplied to DWR staff so that NC‐DWR can do future training sessions. 1 training session will be provided at HDR's CharloƩe Office (440 South Church Street, Suite 1000, CharloƩe, NC 28202)A general meeting will be held, discussing the project and requesting comments on the model schematic This needs to be completed early in the process of adding nodes (February/March timeframe).A data review meeting will be held, to share the data being used for each water system and review of the inflow data set.  A final meeting and training session will be held to explain the final model and train users.Yield ‐ A major component of the SL 2010‐143 is to identify locations where the yield may be inadequate to meet all needs or all essential needs.  A detailed yield discussion is needed to be sure the work that has been completed or planned to be performed for the Catawba reservoirs will meet the needs of the SL 2010‐143.  One approach being used by the State is a period‐of‐record or annual mass curve analysis.  This functionality needs to be built into CHEOPS similar to OASIS, for both reservoir and tributary safe yield determination.NCDWR has requested formation of a small group to discuss this item and  evaluate yield calculation methodology being used for this Basin.  A decsion regarding the methodology will be made after such dicussion(s), as the approach used for reservoirs and tributaries will likely need to be different.?The modeling process is to be open to anyone interested in the model updated, not just the advisory group. Three meetings will be scheduled.3 AddiƟonal tools to allow user defined nodes and allocation of inflow Not significant2 AddiƟonal nodes for each withdrawal and return of 100,000 gpd or more, located in major tributaries to the Catawba in North Carolina and South Carolina Not significant4Additional tools to allow server support access for individual users Not significant5 Miscellaneous ItemsNot significant2/27/2013Page 1 of 2
UPDATED 2-27-2013Catawba‐Wateree CHEOPS Model Development ‐ HDR Responses to NC‐DWR RequestsItem # Functionality Impact to ResultsKey Actions & Understandings Comments Will Incorporate?If model development follows a parallel path with the ongoing Catawba‐Wateree Water Management Group Water Supply Master Plan activities (i.e. CW WMG scenarios are being run while model enhancemen and State version), the CWWMG and stakeholders should decide.Everyone needs to understand tradeoffs from moving forward with the dual apporach.  If the group decides to proceed with this path, the State needs assurances upon EMC approval of the model that the basin users would use only the approved model and that there would not be two competing versions.This approach should be accetpable.Spreadsheet is part of a pre‐processor for inuptting demand information into CHEOPS model.  The spreadsheet is aggregating the demand and discharge data and the model simulates a net withdrawal from each of the lakesNet aggregated approach vs. the nodes at discrete withdrawal and discharge points is part of the discussion on a CWWMG version and a State version of the model.  Both withdrawals and returns are programmed into the CHEOPS model from the pre‐processor spreadsheet.In the spreadsheet, summary tabs for crop irrigation and livestock are not shown, only the compiled monthly numbers.  No explanation of how the estimates were developed is provided.Details on irrigation are not in the master spreadhseet, but rather contained in a separate A/I projection development spreadsheet and the results are then populated into the master spreadsheet. A technical memorandum will be developed to speak to this methodology and access to the A/I projection development spreadsheet will be provided.Approach of using constant monthly demand for A/I has been acceptable in the past since work to date has been focused on the mainstem reservoirs.  Now that more detail on tributaries will be included, NC‐DWR doesn't feel this approach is still valid.An approach that takes in account the annual variability of rainfall should be implemented, as irrigation varies too much from one year to the next depending on rainfall. Agricultural irrigation water use projections will be adjusted seasonally through the use of a seasonal coefficient to account for varying use throughout the year as the result of growing seasons, historical rainfall averages, etc.More definition is needed for the irrigation categorical projections.  This category is currently 1% of the overall basin demand.NC DWR suggested linking evaporation to irrigation, which would need to be performed in the demand spreadsheet (pre‐processor).  To address this concern, HDR will apply a seasonal adjustment factor to irrigation to account for variability of water use for this category during the year.Is modeling the LIP adequate to cover WSRPs? For many of the WSRPs in the CW Basin, the triggers are based on the LIP.  Several systems have additional triggers to provide flexibility, but are not something that can be modeled.  All the WSRP's need to be checked to confirm this is true.Responses need to be evaluated.  The LIP has ranges for the amount of reduction at the various levels.  Most WSRPs have a specfic target.  The WSRPs need to be reviewed to determine the best approach to model the responses.  Develop a template and selection criteria.Tributary systems' WSRPs are not linked to the LIP.  These systems WSRP's need to be included in the model.If tributary systems on the South Fork have WSRP's linked to South Fork streamflow, then to some extent this is linked to the LIP as LIP uses South Fork Streamflow as a trigger.  Local WSRPs for these entities will need to be evaluated individually.?Since the model will be including the tributary users, a basinwide meeting is needed to include all basin users and NC‐DWR defined stakeholders to make them aware of the process and get input on the expanded model schematic.  The EMC has found this basinwide stakeholder process to be important.A CHEOPS training session will be included to assist with this process.  The Catawba Wateree Water Management group will then make a formal request (more of a project update) to the ND‐DWR stakeholder group for acceptance of the CHEOPS model as the accepted model for use by NC‐DWR in the Catawba Basin.CWWMG makes a formal request at end of our project/NC‐DWR stakeholder team to meet quarterly as a joint meeting with DWR and stakeholders.Need to define where cost support comes from and what level of support is to be provided.Hold initial kickoff meeting to introduce the basin planHold model meeting with data and basin layout and present model training session.Hold formal training session to focus on model development and initial reveal.Hold monthly technical team call with NC and SCNeela Sarwar at NC‐DWR is the point of contact for this technical review team, which will also include HDR project management team and modelers and SCDNR staff (if they wish to participate).9678NC‐DWR Stakeholder Meetings and Technical Review TeParallel model development pathWater Shortage Reponse Plans (http://www.ncwater.org/Water Supply Planning/Water Shortage Response Plans/plan) and the CW LIPAgriculture/Irrigation Projections2/27/2013Page 2 of 2