City of Arkadelphia - · PDF fileFigure A5.3 Primary Factors Affecting Low Flow on Ouachita...

Non-Riparian Permit Report

A R K A N S A S

W A T E R

P L A

N

A R K A N S A S

W A T E R

P L A

N

City of Arkadelphia

NON-RIPARIAN INTRA-BASIN TRANSFER

OUACHITA RIVER DIVERSION

Technical Report & Recommendation Arkansas Natural Resources Commission

Sun-Bio Project

City of Arkadelphia Non-Riparian Permit

Table of Contents

TABLE OF CONTENTS

Executive Summary ………….…………………..…………………………………………………….. i

Project Description ……………………………………………………………………………............ i

Permit Considerations ………………………………………………………………………….......... ii

Streamflow …………………………………………………………………………………………………….. ii

Excess Surface Water ….………………………………………………………………..……………….. iii

Environmental Impacts ………………………………………………….………………..……………… iii

Potential Limitations …….………………………………………………………………..……………… v

Recommendations .……….……………………………………………………………………........... vi

A. TECHNICAL ANALYSES …………………………………….…………………………………..... 1

A.1 Available Excess Surface Water ……..……………………………..………………………. 1

Statewide ………………….……………….……………………………………..……………………………. 1

Ouachita River Basin ………………….……………………………………..……………………………. 3

A.2 Subbasin Data …….………………………..…..………………………..……………………….. 5

Controlled & Uncontrolled Drainage Areas ………………………..…………………………… 5

Ouachita River Morphology ….………….………………………………..…………………………… 6

Caddo River Morphology .………………….………………………………..………………………….. 7

Climate Factors ……………….……………………………………….…….……………………………….. 8

A.3 Existing Non-Riparian Use ………..………………………..…………..………………………. 16

Upper Ouachita River Subbasins ………...……………………………..…………………………… 16

A.4 Stream Flow Description ………………..………………………………..………………………. 18

Remmel Dam Releases ………………………...……………………………..…………………………… 18

DeGray Dam Releases …………………………..………………………………………………………….. 20

Arkadelphia Gage ..…..………….……………………………………..…………………………………… 22

A.5 Environmental Considerations ………………………………………..………………………. 24

Instream Resources .….………………….…...……………………………..…………………………… 24

Drought Contingency …………………….…...……………………………..…………………………… 27

Low Flow Condition .………………….…....…..…………………………..…………………………… 28


Table of Contents

TABLE OF CONTENTS

B. AGENCY COORDINATION ….………..……..………………………………………………..... 31

C. PERMIT RECOMMENDATIONS …………………...……..…………………………………. 31

C.1 Curtailment ………………………………………….….……………………………..………………………. 31

C.2 Length of Permit ……………………………….….……………………………..………………………. 31

C.3 Site-Specific Gaging ……..……………….….……………………………..…………….……………. 32

C.4 Reporting Requirements …………….….……………………………..……………..……………. 32

List of Tables

Table ES1 Project Withdrawal & Discharge Quantities …..………………………..………………… i

Table ES2 Withdrawal Rates vs. Ouachita River Flow …………………………..…………………… iii

Table ES3 Permit Monitoring Action Plan ………………………………………………..………………… viii

Table A1.1 Available Excess Surface Water (Ouachita River Basin)…………………..…..……… 4

Table A2.1 Available Excess Surface Water (Ouachita River Subbasins)……….……………… 5

Table A2.2 Temperature and Precipitation ………………………………………………………………… 10

Table A3.1 Active Non-riparian Permits Upstream from Proposed Projects ……………… 17

Table A4.1 Minimum Flow Requirements at Remmel Dam …………………..………………… 19

Table A4.2 Stage Flow Rating Table: Ouachita River at Arkadelphia ………..………………… 22

Table A5.1 Mussel Species in the Ouachita River.. …………………………………..………………… 25

Table A5.2 Palmer Drought Index …………….……………………………………………..………………… 27

Table A5.3 Entergy Drought Contingency Plan Workgroup……………………..………………… 28


Table of Contents

TABLE OF CONTENTS

List of Figures

Figure ES1 Diversion Location ……………………………………....………………………..…………..…….. ii

Figure ES2 Excess Surface Water ………………………………....………………………..…………..…….. iii

Figure ES3 Limitation Factors ……………………………………....………………………..…………..…….. v

Figure A1.1 River Basins in Arkansas ………………………....………………………..…..………..…….. 1

Figure A1.2 Excess Surface Water Diagram ………………....………………………..…………..…….. 2

Figure A1.3 Ouachita River Basin Delineation …………....………………………..…………..…….. 3

Figure A1.4 Ouachita River Basin: 10-Digit HUC ………....………………………..…………..…….. 4

Figure A2.1 Sun-Bio Project Delineation ……………….…....………………………..…………..…….. 5

Figure A2.2 Ouachita River Stream Profile ……………….....………………………..…………..…….. 6

Figure A2.3 Caddo River Stream Profile …………………....………………….……...…………..…….. 7

Figure A2.4 Temperature: July-December …………..…....………………….……...…………..…….. 9

Figure A2.5 Temperature: January-June ……………..…....………………….……...…………..…….. 10

Figure A2.6 Precipitation: January-June ……….……..…....………………….……...…………..…….. 11

Figure A2.7 Precipitation: July-December ……..……..…....………………….……...…………..…….. 12

Figure A2.8 Runoff: January-June ………………….……..…....………………….……...…………..…….. 13

Figure A2.9 Runoff: July-December ……………….……..…....………………….……...…………..…….. 14

Figure A2.10 Precipitation vs. Runoff …………………..…....………………….……...…………..…….. 15

Figure A3.1 Existing Non-riparian Use within Drainage Areas above Sun-Bio Diversion …….……. 16

Figure A4.1 Remmel Dam Minimum Release …………....………………………..…………..…….. 18

Figure A4.2 Monthly Flow Requirements at Remmel Dam …………………..…………..…….. 20

Figure A4.3 Re-Regulation Reservoir Weir downstream of DeGray Lake Dam ….……... 21

Figure A4.4 Minimum Flow through Re-Regulation Reservoir Weir ……....…………..….... 21


Table of Contents

TABLE OF CONTENTS

List of Figures

Figure A4.5 Lowest Recorded Ouachita River Stage …....………………………..…………..…….. 22

Figure A4.6 Average Daily Flow & Arkadelphia (2001-2006) .……………………………..…….. 23

Figure A4.7 Average Daily Flow & Arkadelphia (2006-20011) .………………..…………..……. 23

Figure A4.8 Average Daily Flow & Arkadelphia (2011-2016) .…….…………..…………..…….. 23

Figure A5.1 Example: Intake Head Construction …………..………………..………..………..…….. 26

Figure A5.2 Non-Specific Water Intake Pipe Configuration ……………..……..…………..……. 26

Figure A5.3 Primary Factors Affecting Low Flow on Ouachita River .……..…………..…….. 29

Figure A5.4 Diagram of Ouachita River Projects .………………….……………..…………..…….. 30


Executive Summary i

EXECUTIVE SUMMARY

Project Description

The Sun-Bio facility is to be located in the Clark County Industrial Park south of Arkadelphia on

U.S. Highway 67. Overall project development includes: a water intake and transmission

structures, water/wastewater treatment facilities, rail and road improvements, and other

appurtenances necessary to support the Sun-Bio paper manufacturing facility. The facility will

create paper “bio-products”, up to 690,000 air dried metric tons of dried pulp per year, from

Arkansas’ inventory of unused forest dregs, logging leftovers, imperfect commercial trees, dead

wood and other non-commercial trees in existing forests in the Arkadelphia region.

The city of Arkadelphia will operate the project components necessary to provide potable

water and wastewater treatment services to the Sun Bio facility. Water will be withdrawn from

the Ouachita River near Arkadelphia year round and transported to the Clark County Industrial

Park and treated for process and fire flow water to the Sun Bio facility. The proposed project

does not include development of off-stream storage. Water withdrawn and transported from

the Ouachita River will be treated before entering the Sun Bio facility. Water efficiency within

the facility will be maximized to reduce the amount of unused and untreated process water

leaving the plant. Unused process water leaving the facility will be treated and released back

into the Ouachita River. The average release back into the Ouachita River will be 65-80 percent

of the water originally withdraw. The distance between the water intake and water discharge

structures is approximately six miles. Both structures are to be located along the Ouachita

River. Estimated withdrawal and discharge quantities are listed in Table ES1.

Table ES1: Project Withdrawal & Discharge Quantities

Description Withdrawal Rate Discharge Rate

Peak Daily 29 cfs 19 mgd

Peak Hourly 41 cfs 27 mgd/hr

Average Daily 23 cfs 15 mgd

Average Annual 21,230 acre-ft/yr

Net Consumptive 6 cfs


Executive Summary ii

Figure ES1. Diversion Location

Permit Considerations

On an average annual basis, there is sufficient quantity of excess surface water in the Ouachita

River Basin for this project. Primary considerations for this diversion mostly concern seasonal

streamflow quantities and potential instream impacts to aquatic resources resulting from the

project. The following section provides an overview of these considerations.

Streamflow The proposed diversion on the Ouachita River is located below the confluence of

the Ouachita and Caddo Rivers (see Figure ES1). A significant portion of the upstream runoff

from these two river basins is regulated by Corps of Engineers’ dams. Runoff from the upper

watersheds in the Ouachita River basin is controlled by Blakely (Lake Ouachita), Carpenter (Lake

Hamilton), and Remmel (Lake Catherine) Dams.

However, there is unregulated intervening runoff

below Remmel Dam and the proposed diversion

location at Arkadelphia. Runoff from the Caddo

River Basin is regulated almost entirely through

releases below DeGray Lake Dam, located upstream

of its confluence with the Ouachita River. Water

levels in the reregulation reservoir downstream of

DeGray Lake Dam are maintained to allow pump-

back into DeGray Lake for hydropower generation

and to maintain minimum flows on the Caddo River.

There are minimum releases on the Ouachita and Caddo Rivers below Remmel Dam and the

DeGray Lake reregulation pool. On the Ouachita River, continuous minimum releases from

Remmel Dam vary throughout the year from 200–400cfs as described in the 2003 Federal

Energy Regulatory Commission’s (FERC) relicensing agreement. On the Caddo River, continuous

minimum release from the DeGray Lake reregulation reservoir equals or exceeds 150 cfs.

Minimum releases from these upstream dams contribute to sustained streamflow downstream

of Arkadelphia at the project diversion location. Ouachita River gage records at Arkadelphia

indicate that low recorded stage and accompanying flow was approximately 3.9ft and 600cfs

since FERC relicensed Remmel Dam in 2003. Before 2003, a low stage of 2.8ft was recorded at

Arkadelphia. At a 520cfs Ouachita River flow, the proposed diversion represents 6 percent of

the stream flow at the point of withdrawal. Given the Sun-Bio project will return 60-80 percent

of diverted water back into the Ouachita River after treatment, the net consumptive use when


Executive Summary iii

134,877

42,275

211,620

Excess Surface Water (acre-ft/yr)

Remmel Dam

DeGray Lake Dam

Project Diversion

measured downstream of the discharge to the Ouachita River represents approximately 1

percent of 520cfs. A summary of diversion and streamflow quantities is shown in Table ES2.

Table ES2. Withdrawal Rates vs. Ouachita River Flows

Project Withdrawal Rates Percent of 525cfs Ouachita River Flow at Arkadelphia

Withdrawal Location Discharge Location*

Peak Daily Rate 29.4 cfs 5.6% 1.2%

Peak Hourly Rate 41.3 cfs 7.9% 3.5%

: Discharge of 22.7cfs into Ouachita River is approximately 6 miles downstream of withdrawal location. Note

Excess Surface Water Available non-riparian

excess surface water in Ouachita River

Basin totals 705,401 acre-feet per year

based on the total average annual basin

yield. Figure ES2. includes annual excess

surface water quantities at gages on the

Ouachita River upstream of the proposed

project diversion. Since the instantaneous

quantity of excess surface water physically

available for the proposed project at any

given time is largely controlled by releases upstream, availability or lack of availability is

dependent on operations at Remmel and DeGray Lake dams.

Environmental Impacts In general, potential effects from construction and operation of the

proposed project are described here as either land or water resource impacts. Evaluation of

some potential impacts that could result from the project will require other state or federal

regulatory processes to be completed and are beyond the ANRC’s capacity to investigate.

However, further environmental assessment and impact studies may be required to secure

non-ANRC state and federal permits. Any additional information or data generated through

non-ANRC regulatory processes subsequent to this report will be reviewed and included into

the non-riparian permit file, and if appropriate, will be recognized and incorporated into ANRC’s

permit governing this non-riparian water use.

Figure ES2. Excess Surface Water Quantities


Executive Summary iv

Construction activities associated with the Sun-Bio facility, water/wastewater treatment plants,

river intake, transmission lines, and other appurtenances will cause localized, and in most cases,

temporary disturbances to land resources. These disturbances to jurisdictional lands, whether

temporary or permanent, will be regulated and mitigated through federal regulatory processes.

Potential environmental impacts to land resources are assumed to be non-significant to ANRC’s

review and evaluation of the proposed non-riparian water use.

Many fish and mussel species have been documented in the Ouachita River between the mouth

of the Caddo and the Little Missouri Rivers, including four mussel species that are federally

listed as endangered or threatened. Potential entrainment of these aquatic species in the

water column and disturbance of river bed materials near the water intake are concerns that

affect the design and configuration of the diversion structure. The Arkansas Department of

Environmental Quality’s (ADEQ) National Pollutant Discharge Elimination System (NPDES)

permitting process includes regulation of cooling water intakes for pulp, paper, and paperboard

mills with a design flow greater than 2 MGD. The ADEQ will conduct technical reviews of the

location, design, construction, and capacity of the proposed water intake to ensure: maximum

intake velocities are less than 0.5 feet per second; total design intake flow is less than 5 percent

of the river design technology to minimize impingement mortality; and design technologies to

minimize entrainment and adverse environmental impacts are incorporated into the project.

The ADEQ has verified through preliminary NPDES permit review that preliminary design

configuration of intake structure meets national requirements of Section 316(b) of the Clean

Water Act as referenced above.

Localized effects related to entrainment potential and riverbed disturbance that could

theoretically occur in the immediate area surrounding the intake head cannot be documented

until operation of the intake structure is observed. Once withdrawals commence under normal

operating conditions, monitoring of withdrawals for a specified time period may be required by

non-ANRC regulatory processes to satisfy federal regulatory requirements. At this time, it has

not been documented whether operation of the project will adversely impact endangered or

threatened mussel species that possibly could exist in close proximity to the intake structure.

The net consumptive loss or net reduction in Ouachita River streamflow will be minimal and is

approximated to be 7 cfs. It is assumed any significant environmental impact from reduction in

streamflow will occur in the approximately six mile stretch of Ouachita River between the

project’s water intake and discharge locations. As shown in Table ES2, the amount of diversion


Executive Summary v

represents five percent of 520cfs, the low Ouachita River flow recorded at the Arkadelphia gage

since continuous releases from Remmel Dam began in 2003.

Water quality impacts associated with the project affecting temperature, dissolved oxygen, or

other water chemistry parameters are not determined by ANRC as part of the non-riparian

permitting process. Any water quality issues will be addressed by non-ANRC regulatory and

monitoring processes. Potential requirements or recommendations from non-ANRC regulatory

processes intended to reduce or eliminate possible water quality impacts will be incorporated

into ANRC’s non-riparian permit conditions if appropriate.

Potential Limitations Establishment of project withdrawal limitations requires investigation and

an understanding of the interaction between upstream lake operations, water management

activities, on-site factors, and year-to-year seasonal weather patterns. Releases from Remmel

and Lake DeGray Dams for power generation and flood control functions significantly affect

occurrence and duration of low flows on the Ouachita River downstream. In addition, extreme

weather patterns which generate extended drought and flooding events affect the schedule of

dam releases. For these reasons, withdrawal limitation(s) should be evaluated based on a

“multi-tiered” approach and an evaluation

of the relationship between the following:

upstream dam releases and downstream

flow conditions, runoff & precipitation

(forecasting) data, and potential negative

instream impacts which could result from a

combination of circumstances or series of

events. Figure ES3 shows these factors as

primary influences in determining when

restrictions are warranted. As an example,

when upstream (storage) lake levels

necessitate significant reduction of dam

releases for power generation and minimum

environmental instream flows, restriction of

withdrawals downstream may be warranted

if- flows near the withdrawal location are

judged to be inadequate to sustain aquatic

resources and the replenishment of

upstream lake levels and streamflow from runoff or precipitation is not likely (forecasted) to

Restriction

No Restriction

Downstream Conditions:

Critical Low Flows

Runoff & Precipitation:

Extended Drought

Lake Levels:

Reduction in Dam Releases

Figure ES3 Limitation Factors

Restriction

No Restriction

Downstream Conditions:

Critical Low Flows

Runoff & Precipitation:

Extended Drought

Lake Levels:

Reduction in Dam Releases


Executive Summary vi

occur within a specified time period. In this scenario, circumstances and concurrent conditions

would contribute to possible restrictions being imposed on out-of-stream withdrawals in order

to provide a minimum level of protection for instream needs.

Recommendations

Environmental Impacts Annually, there exists sufficient excess surface water in Ouachita River

subbasins upstream of the proposed project to permit this diversion. There is no evidence from

historical period of record flow analyses to indicate this withdrawal, including existing non-

riparian withdrawals upstream, will alter seasonal Ouachita River flow patterns. There remain

some unanswered questions related to potential environmental impacts resulting from the

project. These impacts are more closely associated with physical conditions existing in the six

mile stretch of Ouachita River between the intake and discharge locations and in areas

immediately around these two structures during normal withdrawal and discharge operations.

Any environmental impacts that may result from project construction and normal withdrawal

operations should be verified through other non-ANRC regulatory processes. Recommended

actions to address potential environmental impacts associated with construction and start-up

of the project under non-critical (average or above) Ouachita River flows are included below:

Stream Flow The net consumptive use will be unmeasurable when comparing Ouachita River

flow upstream of the intake and downstream of the discharge structures. Therefore, the six

mile stretch of Ouachita River between the intake and discharge structures will experience a

loss of flow equal to the amount of diversion at the intake structure. This loss is quantified in

Table ES2 and equals five to eight percent of 520cfs, which is representative of low recorded

Ouachita River flow at Arkadelphia since continuous minimum release at Remmel Dam began in

2003. A multi-triggered monitoring action plan is recommended to evaluate and verify

concurrent conditions which, in combination, result in or are predicted to result in an ANRC

declared and require allocation of surface water withdrawal according to ANRC Rules shortage

for Utilization of Surface Water. A is defined as a condition when all beneficial water shortage

uses cannot be met.

relevant data from federal or other non-ANRC regulatory Evaluate and incorporate

environmental assessment processes into non-riparian permit conditions if construction or

normal operation of the project would be affected by results from these data. As well, if

monitoring of project withdrawals is required to complete non-ANRC regulatory processes, all

monitoring data should be evaluated for inclusion into the permit if necessary.


Executive Summary vii

Table ES3 contains the recommended Permit Monitoring Action Plan (PMAP) which identifies

conditions affecting streamflow at Arkadelphia and the downstream withdrawal location. The

PMAP is the check-list to verify: a) multiple conditions (triggers) exist or are forecasted to exist

or remain in the future, and b) a combination of these existing or forecasted circumstances and

conditions may require management action(s) from ANRC and the permittee. The conditions

described in the PMAP will be evaluated by ANRC to determine the net impact of the project on

instream environment and existing in-situ streamflow conditions. The permittee is responsible

for monitoring conditions on the Ouachita River at the Arkadelphia gage and upstream to the

extent necessary to fully coordinate and comply with ANRC during a declared when shortage

restriction of out-of-stream withdrawals may be necessary. Table ES3 contains red, yellow, and

green text corresponding to colored bars on either side of the table. This color scheme is

intended to mimic a theoretical staff gage on an unnamed stream, colored to indicate levels

when restrictions on withdrawals would occur, i.e. stage level in red would represent restriction

or shut-off. Likewise, corresponding items colored red within Table ES3 represent concurrent

conditions that have to exist in order for ANRC to consider restrictions on project withdrawals.

Recommended actions to address impacts and effects of project withdrawals on Ouachita River

during periods of low flow and other critical conditions are listed below:

Incorporate Permit Monitoring Action Plan (PMAP) into the final permit to describe

trigger thresholds and other considerations ANRC will use to evaluate shortages in Ouachita

River subbasins which could affect normal project operations and withdrawals from the

Ouachita River.

if any, and incorporate into Determine site-specific stream monitoring requirements,

the non-riparian permit after all non-ANRC regulatory processes have been completed. ANRC

will use site-specific gaging, if installed, to evaluate shortages in Ouachita River subbasins and

implement surface water allocation during a shortage.


Executive Summary viii

Table ES3. Permit Monitoring Action Plan: City of Arkadelphia Non-Riparian Permit

Location(s) Existing Condition (Trigger) ANRC Management Action(s)

Remmel Dam DeGray Lake Dam Arkadelphia Gage

Existing conditions at all sites above trigger thresholds

None

DeGray Lake Dam (Average Daily Flow)

(Weir) <150 cfs

1) Contact Vicksburg District Corps of Engineers to verify operational deviations at DeGray Lake Dam and document existing conditions

2) Document average daily releases from Remmel Dam

3) Document average daily flow at Arkadelphia gage

Remmel Dam (Average Daily Flow)

(Jan-Feb) <200cfs (March) < 400cfs (April) < 350cfs (May) < 250cfs (June-Nov) < 200cfs (Dec) < 250cfs

1) Contact Entergy Corporation to verify deviation in minimum flow releases at Remmel Dam and document existing conditions at Blakely Dam

2) Document average daily flow at DeGray Lake Dam

3) Document average daily flow at Arkadelphia gage

Arkadelphia Gage Average Daily Stage <4 ft 1) Check conditions at DeGray Lake and Remmel Dams

2) Verify precipitation stats and forecasts

Remmel Dam DeGray Lake Dam Arkadelphia Gage

1) Existing conditions at all sites meet trigger thresholds

2) Entergy implements drought contingency planning

1) Compare project withdrawals and Ouachita River flows

2) Document precipitation statistics and forecast 3) Evaluate conditions existing at all sites and

implement restrictions if determined necessary 4) Coordinate ANRC action with Entergy’s drought

contingency planning efforts

Permittee Management Responsibilities- Maintain a monitoring system capable of reporting instantaneous and average daily withdrawal rate(s) to ANRC when requested, complying with permit provisions and annual compliance reporting, and adhering to provisions in Title 3 Rules for Utilization of

Surface Water.


Executive Summary ix

Permit Issuance In addition to annual compliance and reporting, overall project operations

affecting withdrawals from the Ouachita River should be re-evaluated at least every 10 years to

confirm existing permit conditions are appropriate and project withdrawals are not adversely

impacting instream or other resources in Ouachita River subbasins. The frequency of re-

evaluation should coincide with expiration dates on non-riparian permit. A provisional permit

should be issued initially to remain in effect until construction and start-up of project, federal

regulatory, environmental assessment, and permitting processes are completed. A final permit

should be issued when the project begins normal withdrawals from the Ouachita River and

after any environmental monitoring that is required by other non-ANRC processes have been

completed. Recommended actions to address issuance of the final permit and frequency of re-

evaluation are listed below:

(to include any environmental and regulatory data from non-Issue non-riparian permit

ANRC processes once completed) for a period of 25 years, with regular, periodic evaluation of

project withdrawals and permit conditions during this 25 year period. These evaluations will

verify that existing permit conditions remain appropriate and normal project withdrawals are

not negatively impacting instream or other environmental resources in the upper Ouachita

River watershed.


Technical Analyses 1

Figure A1.1 River Basins in Arkansas

A. TECHNICAL ANALYSES General analyses were conducted to evaluate water availability in the Ouachita River Basin and

identify potential effects of the proposed Sun-Bio non-riparian diversion on land and water

resources in the watershed. These efforts were focused primarily on water availability and

stream flow analyses within the context of existing ANRC Rules for the Utilization of Surface

Water and enabling Commission authority enumerated in state water law. Additional studies

and review of more detailed project design and proposed operations may be required in other

federal and state regulatory processes. Information and data generated from non-ANRC state

or federal regulatory processes will be reviewed by Arkansas Natural Resources Commission

staff and incorporated into the non-riparian water use permit where appropriate.

A.1 Available Excess Surface Water

Statewide

On an average annual basis, there is estimated to be 8.7 million acre-feet per year of excess

surface water available for interbasin transfer and use by non-riparians. It is important to note-

although there is an abundance of water available on an average annual basis; demand for that

water does not necessarily occur during times of the year when the water is physically

available. Therefore, streamflow variability and possible reoccurring seasonal and multi-year

flow patterns need to be identified when determining physical availability of water at individual

locations within a specific basin or sub basin.

Excess surface water is quantified statewide by 9

river basins and 32 sub basins in the recent 2014

Arkansas Water Plan update (see Figure A1.1). The

amount of surface water available for non-riparian

use is defined as excess surface water in ANRC Title

3, Rules for the Utilization of Surface Water. Title 3

specifies excess surface water will be calculated

from the average annual basin yield, existing uses,

instream flow, and future water demands. Excess

surface water is quantified as 25 percent of the total

available water summarized in the 2014 Arkansas

Water Plan. Total available water is the amount of

water over and above what is required to meet both instream and out-of-stream water needs.



Instream needs are quantified by the Arkansas Game & Fish Commission’s Arkansas Method

and is the highest of instream flow considerations in most basins.

Figure A1.2 divides total average annual basin yield (runoff) among in-stream and out-of-stream

needs (demand) and total available water (potential for future use). Excess surface water in

Figure A1.2 is highlighted in RED and is equal to 25% of Total Available Water on an annual basis.

The 25% is calculated by basin or individual Hydrologic Unit Code (HUC) and represents the

quantity, by basin or HUC, available to permit non-riparian water use.

Figure A1.2 Excess Surface Water Diagram

Existing Riparian Use Federal Projects Projected Future Riparian Use

Basin Yield

In-Stream Needs Excess Surface Water (25% of total available water)

Total Available Water (Potential for future use)

Average Annual

Out-of-Stream Needs

Aquifer Recharge, Fish & Wildlife, Navigation, Water Quality, Recreation, and Interstate Compacts



Ouachita River Basin

The Ouachita River Basin, located in the southwest region of Arkansas, comprises 10,885 square

miles. The Ouachita River Basin includes several subbasins which are delineated in the 2014

Arkansas Water Plan (AWP). In Figure A1.3 below, the Saline River subbasin is delineated within

the Ouachita River Basin for purposes of calculating excess surface water quantities for the Sun-

Bio Project. In determining excess surface water for this project, the 3,230 square mile Saline

River subbasin does not contribute any surface water runoff above the project location and

therefore must be subtracted from the overall Ouachita River Basin area. The remaining

drainage area for the Ouachita River Basin is 7,655 square miles.

The 2014 AWP estimates total excess surface water for 10,885 square miles of the Ouachita

River Basin at 1,349 cubic-feet per second or 977,583 acre-feet per year. The Saline River

subbasin comprises approximately 27 percent of the Ouachita River Basin and excess surface

water for this subbasin is estimated at 272,182 acre-feet per year. Removing the Saline River

subbasin leaves 73 percent of the Ouachita River Basin with excess surface water estimated at

705,401 acre-feet per year. The drainage area above the Sun Bio Project diversion is

approximately 30 percent of the remaining Ouachita River Basin area, which equates to

Figure A1.3 Ouachita River Basin Delineation



211,620 acre-feet per year of excess surface water. The Ouachita River Basin’s 10-digit HUCs

and the Sun-Bio Project drainage area are shown in Figure A1.4.

Table A1.1 contains available annual excess surface water quantities for the Ouachita River

Basin and its subbasins. Annual excess surface water for the Sun-Bio Project is estimated to be

211,620 acre-feet per year.

Table A1.1 Available Excess Surface Water (Ouachita River Basin)

Available Excess Surface Water Drainage Area Acre-Ft/Year

Ouachita River Basin 100% 977,583

Saline River Subbasin 27.8% - 272,182

Ouachita River subbasin 72.2% 705,401

Sun Bio Project 21.6% 211,620

Figure A1.4 Ouachita River Basin: 10-Digit HUC Delineation



Figure A2.1 Sun-Bio Project Delineation

A.2 Subbasin Data

Controlled & Uncontrolled Drainage Areas

For excess surface water calculation, hydrologic runoff analyses, and assessment purposes, the

Sun-Bio Project subbasin has been delineated as shown in Figure A2.1 and encompasses 2313

square miles originating in the headwaters of the Ouachita River and ending at the project

diversion location near Arkadelphia. The project’s watershed is equivalent to thirty percent

(30%) of Ouachita River subbasin, excluding the Saline River subbasin. Available excess surface

water for this portion of the Ouachita

River subbasin is equivalent to 973

cubic-feet per second or 705,401

acre feet per year. The project’s

drainage area is transected by two

primary river systems and delineated

into the Caddo and Ouachita River

subbasins. Historical period of record

gage data provide analyzes capability

for these two subbasins: 1) 07359002

Ouachita River at Remmel Dam

above Jones Mill, Arkansas, and 2)

07359910 Caddo River at DeGray

Regulating Dam near Arkadelphia,

Arkansas.

Table A1.2 below contains available

excess surface quantities for the two hydrologic subbasins and shows that eighty eight percent

(88%) of the project’s drainage area (runoff) is regulated through Remmel and DeGray Lake

Dams. Approximately twelve percent (12%) of the subbasin drainages are not controlled by

these two dams and thus represents the unregulated portion of flow measured at the

Arkadelphia gage.

Table A2.1 Available Excess Surface Water Quantities (Ouachita River Subbasins)

Drainage Area % of Project Runoff Excess (cfs) Excess (ac-ft/yr)

Above Remmel Dam 1550 mi2 67% 186 134,877

Above DeGray Dam 480 mi2 21% 58 42,275



Ouachita River Morphology

The Ouachita River headwaters are located in western Arkansas at an elevation of

approximately 1572 feet (NAD 83). The stream profile drops 1,402 feet over the course of 196

miles to the diversion location near Arkadelphia. Figure A2.2 shows the Ouachita River stream

profile from the headwaters to the diversion location and includes Blakely Dam which creates

Lake Ouachita, Carpenter Dam which creates Lake Hamilton, and Remmel Dam which creates

Lake Catherine. The stream profile is indicative of Ouachita Mountains terrain and associated

topography.

Figure A2.2 Ouachita River Stream Profile



Caddo River Morphology

The Caddo River headwaters are located in western Arkansas at an elevation of approximately

1148 feet (NAD 83). The stream profile drops 969 feet over the course of 85 miles to the

confluence of the Ouachita River east of Caddo Valley. Figure A2.3 shows the stream profile

from headwaters to the confluence and includes DeGray Dam which creates Lake DeGray and

the Reregulation Dam which creates the Regulating Pool. Headwaters of the Caddo River

mirror similar runoff and slope characteristics consistent with the Ouachita Mountains.

Figure A2.3 Caddo River Stream Profile



Climate Factors

Temperature, precipitation, and runoff are interrelated factors that affect stream flow and lake

level in the Ouachita River Basin. Temperature affects weather patterns and specifically rates

of evaporation from lakes and streams in the basin. Higher temperatures increase the rate of

evaporation. Extended duration and more frequent occurrence of higher temperatures (loss),

in combination with lack of precipitation (recharge), influence significantly water availability on

a seasonal basis. Therefore, seasonal climate and stream flow trends should be identified and

evaluated when data is available. Historical high, low, and average temperatures in the project

watershed are included in Table A2.2 below. Temperature, precipitation, and runoff (lake

storage, etc.) are factors associated with forecasting future drought and intensity of droughts.

These factors may need to be monitored during a declared . Figures A2.4 through A2.9 shortage

on pages 9-14 contain period of record monthly means for temperature, precipitation, and

runoff in the project subbasin. Data from NHDPlus Version 2.1 data set was used to create the

maps for these figures.

Figure A2.10 on page 15 correlates annual mean temperature and precipitation with runoff.

Runoff is most critical beginning the end of July and continuing through August, September and

October, which is historically when temperatures are warmest and precipitation lowest. These

months represent the time of year when climatic conditions have the greatest potential for

affecting Ouachita River flow in the project subbasin.

Table A2.2 Temperature and Precipitation

Temperature (Fahrenheit)

High (annual) 74.2°

Low (annual) 49.8°

Average 62°

Annual Precipitation Mean

57.1 Inches



Figure A2.4 Temperature: July-December



Figure A2.5 Temperature: January-June



Figure A2.6 Precipitation: January-June



Figure A2.7 Precipitation: July-December



Figure A2.8 Runoff: January-June



Figure A2.9 Runoff: July-December



0.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

8.00

9.00

10.00

Janu

ary

Febr

uary

Mar

ch

April

May

June July

Augu

st

Sept

embe

r

Oct

ober

Nov

embe

r

Dec

embe

r

Mea

n M

onth

ly A

vera

ge

(Yea

rs re

cord

ed 1

970

-200

0)(In

ches

)

Precipitation Versus Runoff

Run Off Precipitation

39.244.1

52.3

60.2

68.1

75.780.2 79.1

72.3

61.5

50.4

41.9

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

90.0

Janu

ary

Febr

uary

Mar

ch

April

May

June July

Augu

st

Sept

embe

r

Oct

ober

Nov

embe

r

Dec

embe

r

Mea

n M

onth

ly A

vera

ge T

empe

ratu

re (Y

ears

197

0 -2

000)

(Fah

renh

eit)

Temperature

Figure A2.10 Precipitation vs.Runoff



A.3 Existing Non-Riparian Use

Upper Ouachita River Subbasins

The ANRC Non-Riparian Water Use Program holds five active permits within the 2,313.75

square mile delineated watershed drainage area upstream of the proposed (Sun Bio) project

diversion on the Ouachita River (see Figure A3.1 for locations of these five diversions). Four of

the five active permits collectively divert 91,900 acre-feet per year within a 37 mile segment

(length) of the Ouachita River. Of those five diversions, MN06-13 is the northern most

diversion located on Lake Hamilton between Blakely and Carpenter Dams. Permits 02-13, 01-

11, and 00-10B are both located below Remmel Dam. The one remaining active permit, 1687-

13 diverts 61 acre-feet per year from the Caddo River and is located upstream of Lake DeGray

and Lake DeGray Dam.

Table A3.1 on the following page provides a listing of active non-riparian permits located in the

drainage area above the proposed Sun Bio project. Each listing provides the Name of the

Permittee, Date the permit was issued, Water Source, Latitude (decimal degrees), Longitude

(decimal degrees), Drainage Area in square miles above diversion location (if known), Estimated

Low Flow in cubic feet per second (if known), Estimated Daily Discharge of the water source in

cubic feet per second (if known), Maximum Diversion Rate in cubic feet per second of the

diversion, and the Annual Maximum Permitted Volume in acre-feet per year.

Figure A3.1 Existing Non-riparian Use within Drainage Areas above Sun Bio diversion



Table A3.1 – Active Non-riparian Permits Upstream from Proposed Project

NRWU Permit MN06-13 Permittee: City of Hot Springs Date of Issuance: 01/27/2014

Source Latitude Longitude Drainage Area

Estimated Stream Flow Conditions

Max Diversion Rate Max Annual Volume Permitted Low Flow Daily Average

Lake Hamilton 34.549925 -93.183721 1,103.85mi2 56cfs 1,460cfs 36cfs 22,420 acre-ft/year

The City of Hot Springs, Arkansas is permitted to withdraw 30 million gallons per day (MGD) from Lake Hamilton, not to exceed an average of 20 million gallons per day (MGD) within a rolling 3-month period.

NRWU Permit 02-13 Permittee: James Kimzey Regional Water District Date of Issuance: 05/13/2002




Ouachita River 34.432 -92.8787 - - - 39cfs 28,000 acre-ft/year

The James Kimzey Regional Water District depends on two water sources to supply its system. This diversion is for the Ouachita River at Jones Mill (Kimzey East). The projected need for potable water supplied by Kimzey East is 12 million gallons per day (MGD). The District is also under contract with Hot Spring Power Company, L.L.C. (HSPC) to supply 6 MGD of raw water from the Ouachita River to a 720 megawatt (MW) power generating station northwest of Malvern. The proposed generation station could expand to 1500 MW, at which time the full capacity of 12 MGD of raw water will be required. To meet the combined needs of the District, the permitted diversion is for 28,000 acre-feet per year.

NRWU Permit 00-10 B Permittee: Malvern & Quad-County Public Facilities Board Date of Issuance: 05/15/2000





The City of Malvern and the Quad County Public Facilities Board is permitted to withdraw a maximum of 24 million gallons per day (MGD) from the Ouachita River for municipal water supply.

NRWU Permit MN06-13 Permittee: Entergy Arkansas, Inc. Date of Issuance: 09/21/2000



Max Diversion Rate Max Annual Volume Permitted Low Flow Daily Discharge


Entergy Arkansas’s is permitted to withdraw 13 MGD to support a 620 Megawatt (MW) natural gas-fired combined-cycle Hot Springs generating plant, 5 miles southwest of Malvern, Arkansas. The largest consumption in the power plant is make-up water for the cooling system, whose water is primarily used in a surface condenser to cool and condense low energy steam. The low energy steam is used to drive a steam turbine, and after condensation, the water is returned to the steam generator system.

NRWU Permit 1687-13 Permittee: Glenwood Country Club Date of Issuance: 07/09/2013



Max Diversion Rate Max Annual Volume Permitted Low Flow Daily Discharge

Caddo River 34.32415 -93.533978 1,103.85 21cfs 17cfs 1cfs 61 acre-ft/year

The diversion is for Glenwood Country Club in Glenwood, Arkansas to withdraw a maximum of 61 acre-feet per year from the Caddo River. The water withdrawn is stored in holding ponds and ultimately used to irrigate the fairways and greens.



A.4 Stream Flow Description

Remmel Dam Releases

Entergy, prior to the FERC licensing agreement of 2003, was allowed to withhold and reduce

water releases from Remmel Dam in order to maximize power generating capacity through

management and maintenance of lake levels upstream. This had an effect of marginalizing

downstream consistency, allowing fluctuations in stream flow throughout any given period of

time. Under the current FERC licensing there is now a requirement for continuous minimum

daily flow which varies by month (see Table A4.1 and Figure A4.1).

Remmel Dam creates Lake Catherine and Carpenter Dam creates Lake Hamilton. The dams and

lakes together form the Federal Energy

Regulatory Commission Project #271. Under

normal conditions, Lake Ouachita levels

slowly fall through hydroelectric generation

through Carpenter and Remmel dams. Lake

Ouachita is then allowed to refill during the

winter months through rainfall. To conserve

water during drought conditions, FERC

licensing allows Entergy to restrict power

generation in the fall season at Remmel and

Carpenter dams, and if necessary through a

request for temporary deviation from Article

401, reduce the flow from Remmel dam

below the normal minimum Federal Energy

Regulatory Commission (FERC) requirements.

The contingency plan allows a reduction in the continuous minimum flow normally required

from Remmel Dam into the Ouachita River to conserve water in Lake Ouachita. In addition,

operations under the FERC license require and authorize Entergy to control certain activities

that affect the lake’s environmental, safety and recreational values.

Should the drought contingency plan be requested, the Licensee can initiate a consultation

meeting during a moderate drought and make recommendations to the Commission. During

extreme drought conditions, Entergy may request the FERC to lower the minimum required

flow by 10%, below the already existing or agreed upon reduced rate of 200cfs by an additional

10%, to a new minimum of 180cfs, if agreed upon by the Commission.

Figure A4.1 Remmel Dam Minimum Release



The drought plan is written such that it is implemented at Entergy’s option once the Moderate

or Severe Drought trigger is met. This option would likely be exercised if it were late in the

summer, fall or spring when there is a desire to refill Lake Ouachita and they are ready to stop

generating power. The exact level of Lake Ouachita is a variable and would be a management

decision at the time a critical decision is made on whether to continue to generate and thus pull

the lake down further, or to stop generation and allow it to refill. This Entergy option, once

implemented, imposes limitations on generation to emergency system needs only. Decisions

will be affected based on an evaluation of the level of the lake versus the desire to continue

generation which does not allude to a specific lake level.

Minimum flow requirements (without hydropower generation), as specified in the FERC license

for Remmel Dam, are shown below in Table A4.1.

Monthly minimum flow requirements described above and contained in Entergy’s drought

contingency plan are shown in Figure A4.2. These flows represent potential incremental

reductions in minimum flow from Remmel Dam during drought conditions. Entergy would

reduce minimum flows at Remmel Dam in order to conjunctively manage levels in Lakes

Ouachita, Hamilton, and Catherine. A full description of Entergy’s drought contingency

responsibilities and guidelines is contained in a later section of this report.

Table A4.1 Minimum Flow Requirements at Remmel Dam

Month Minimum Flow Requirement

January 300cfs

February 300cfs

March 400cfs

April 350cfs

May 250cfs

June-November 200cfs

December 250cfs



0

50

100

150

200

250

300

350

400

Required flow cfs- normal conditions

Minimum flow cfs- moderate drought

Minimum flow cfs- extreme drought

Figure A4.2 Monthly Flow Requirements at Remmel Dam (Entergy’s drought contingency plan)

DeGray Lake Dam Releases

Caddo River streamflow is controlled by a permanent weir in the re-regulation reservoir

immediately downstream of DeGray Lake Dam. The purpose of the permanent weir (low water

dam) is to allow water from the re-regulation reservoir to be pumped back into DeGray Lake

during off-peak times when electricity costs are relatively cheaper, creating the potential to

generate electricity from releases through DeGray Lake Dam when hydropower power is

needed and energy can be produced at a profit. The re-regulating pool has 5 water release

gates, two of which remain open year round to allow a continuous flow of 150cfs out of the re-

regulation reservoir. Figure A4.3 shows the permanent weir structure which controls water

levels in the re-regulation reservoir. Continuous flow through the two open gates is shown in

Figure A4.4.



Figure A4.3 Re-regulation Reservoir Weir downstream of DeGray Lake Dam

150 ft3/sec minimum flow through two gates

Figure A4.4 Minimum Flow through Re-regulation Reservoir Weir

Gates open at all times



0.0

1.0

2.0

3.0

4.0

Figure A4.5 Lowest Ouachita River Stage

Arkadelphia Gage

The term “gage height” or stage (usually measured in feet) is used when referring to elevation

of the water surface as measured at the gaged location. At some gaging stations, rating curves

have been created to develop correlations between stage measurements and stream discharge.

However, stream channels are irregular in shape and cross-sectional area at any given location.

Therefore, correlations between stage and discharge are generally not linear.

Ouachita River discharge was recorded and reported at the Arkadelphia gage prior to 1973.

From 1973 to present, stage readings only have been reported by the Vicksburg District Corps

of Engineers and used to estimate stream discharge (flow) at Arkadelphia, implying that the

rating curve was most likely developed prior to 1973. The Vicksburg District indicates the rating

table (see Table A4.2) is sufficiently accurate at stages above 4ft, but is less confident in flow

accuracy at stages below 4ft. At a 3ft stage, flow is estimated to be approximately 400cfs.

Lowest recorded Ouachita River flow at

Arkadelphia is shown in Figure A4.5. Since the

FERC relicensing agreement at Remmel Dam

in 2003, the lowest recorded stage at

Arkadelphia gage is 3.9ft or approximately

600cfs. Figures A4.6, A4.7, and A4.8 show

average daily stream flows from 2001-2016,

reflecting effects of instantaneous continuous

minimum releases from Remmel Dam after

2003.

Table A4.2 Stage Flow Rating Table: Ouachita River @ Arkadelphia

Stage Flow Stage Flow Stage Flow

3ft ≈400cfs 12ft 13800cfs 20ft 32000cfs

4ft 630cfs 13ft 15400cfs 21ft 34700cfs






10ft 9900ft 19ft 29200cfs 27ft 88197cfs

11ft 11900cfs



Figure A4.6 Average Daily Flow @ Arkadelphia (2001-2006)





A.5 Environmental Considerations

Instream Resources

The Arkansas Game & Fish Commission has identified aquatic species (mussels and fish) that

are documented in the Ouachita River between the mouth of the Caddo and the Little Missouri

Rivers. Forty-one mussel species are known to occur within this segment of the Ouachita River

and includes several species that are federally listed as endangered (3) or threatened (1). An

additional 14 species are designated as Species of Greatest Conservation Need (SGCN) in the

Arkansas Wildlife Actin Plan. This segment of the Ouachita River contains at least four sites that

are occupied by the Endangered Spectaclecase mussel, one of which is the most robust

population known for the Ouachita River while a smaller population occurs at the City of

Arkadelphia water intake structure. While not in immediate proximity to the proposed

Ouachita River intake structure, the Federally Threatened mussel, Lampsilis powellii (Arkansas

fatmucket), occurs in the Caddo River upstream of its confluence with the Ouachita River and in

the Ouachita River upstream of the mouth of the Caddo River. The status of this species within

the segment of the Ouachita River between the mouth of the Caddo River and Little Missouri

River is currently unknown but the species could occur in this segment of the Ouachita River

since biotic and abiotic factors are capable of supporting this species. Ninety fish species have

been documented in this segment of the Ouachita River. Only one, Alabama shad, has a federal

status, which is a Candidate for listing. Twelve additional fish species are of conservation

concern, as designated by their SGCN status in the Arkansas Wildlife Actin Plan.

Mussel species which occur in the Ouachita River upstream from the proposed diversion are

listed in Table A5.1. Primary concern for these species involves potential entrainment and

riverbed material disturbance that could occur near the water intake head. The ADEQ has legal

responsibility to verify water intake design and proposed operations meet NPDES federal

guidelines and criteria. Further detail on federal criteria is included in the Executive Summary

section of this report. Figure A5.1 shows construction of intake manifold similar in design to the

proposed Sun Bio project.



Table A5.1 Mussel species in the Ouachita River (between Caddo & Little Missouri River confluences)

Species Common Name G Rank S Rank Federal Status SGCN

Actinonaias ligamentina Mucket G5 S4

Alasmidonta marginata Elktoe G4 S3

Y

Amblema plicata Threeridge G5 S5

Anodonta suborbiculata Flat floater G5 S4

Arcidens wheeleri Ouachita rock pocketbook G1 S1 Endangered Y

Cumberlandia monodonta Spectaclecase G2G3 S2 Endangered Y

Cyprogenia sp. cf aberti "Ouachita" Fanshell G2 S3

Y

Ellipsaria lineolata Butterfly G4 S4

Elliptio dilatata Spike G5 S5

Fusconaia flava Wabash pigtoe G5 S5

Lampsilis abrupta Pink mucket G2 S3 Endangered Y

Lampsilis cardium Plain pocketbook G5 S5

Lampsilis hydiana Louisiana fatmucket G4 S4

Lampsilis ornata Southern Pocketbook G5 S2

Y

Lampsilis teres Yellow sandshell G5 S5

Leptodea fragilis Fragile papershell G5 S5

Ligumia recta Black sandshell G5 S4

Ligumia subrostrata Pondmussel G4G5 S4

Megalonaias nervosa Washboard G5 S4

Obliquaria reflexa Threehorn wartyback G5 S5

Obovaria arkansasensis Ouachita creekshell G2 S4

Y

Plectomerus dombeyanus Bankclimber G4 S4

Pleurobema rubrum Pyramid pigtoe G2 S4

Y

Pleurobema sintoxia Round pigtoe G4 S3

Y

Potamilus purpuratus Bleufer G5 S5

Ptychobranchus occidentalis Ouachita kidneyshell G3G4 S4

Y

Pyganodon grandis Giant floater G5 S5

Quadrula cylindrica cylindrica Rabbitsfoot G3 S3 Threatened Y

Quadrula metanevra Monkeyface G4 S4

Quadrula nobilis Gulf mapleleaf G4 S3

Y

Quadrula nodulata Wartyback G4 S4

Quadrula pustulosa Pimpleback G5 S5

Quadrula quadrula Mapleleaf G5 S4

Quadrula verrucosa Pistolgrip G4 S5

Reginaia ebenus Ebonyshell G4G5 S3S4

Strophitus undulatus Creeper G5 S4

Toxolasma parvum Lilliput G5 S3

Toxolasma texasense Texas liliput G4 S3

Y

Truncilla truncata Deertoe G5 S4

Utterbackia imbecillis Paper pondshell G5 S4

Villosa sp. cf lienosa Little spectaclecase G5 S3

Y

Total Mussel Taxa: 41



Figure A5.1 Example: Intake Head Construction

Radial Intake Screening

Crushed Stone

Figure A5.1 shows construction of an intake

manifold head similar in design to the City

of Arkadelphia diversion project. Figure

A5.2 shows a common configuration for

river intake piping and manifold. As shown

in Figure A5.1, the intake pipes are buried

and covered with crushed rock and stone.

The intake manifold is wrapped in radial

screenings as shown in Figures A5.1-A5.2,

which helps reduce entrainment potential

and entrance velocities. The streambed is

disturbed temporarily during construction,

but once installed the intake heads do not

present significant instream obstructions.

Figure A5.2 Non-Specific Intake Pipe Configuration

Profile

Plan





Localized effects related to entrainment potential and riverbed disturbance that could occur in

the immediate area surrounding the intake head cannot be documented until operation of the

intake structure is observed. Once withdrawals commence under normal operating conditions,

monitoring of withdrawals for a specified time period may be required by regulatory agency(s)

to satisfy federal permit conditions and standards. It has not been documented whether

operation of the project will adversely impact endangered or threatened mussel species that

may exist in near proximity to the intake and discharge structures.

Drought Contingency

Minimum releases from Remmel Dam are affected by moderate to severe drought conditions.

Entergy’s Drought Contingency Plan Responsibilities and Guidelines enumerate measures

specified in the FERC license which establish monthly minimum flow requirements from

Remmel Dam. Entergy monitors drought indices and identifies when conditions for triggering a

response have been met. Entergy will periodically obtain the most recent and appropriate

Palmer Hydrological Drought Index report from the National Climatic Data Center (NCDC),

National Oceanic and Atmospheric Administration (NOAA) and the National Environmental

Satellite Data and Information Service (NESDIS). Should a review of this data show that a

drought condition exists; Entergy will initiate provisions of the drought contingency plan.

The Palmer Drought Index (PDI) is used as an indicator of drought severity, and a particular

index value is often the signal to begin or discontinue elements of a drought contingency plan.

The Standardized Precipitation Index (SPI) quantifies a precipitation deficit for different time

scales and it is often used in conjunction with the Palmer Drought Index. The Palmer Drought

Index uses a scale of +4 to –4, which identify wet to dry conditions (see Table A5.2).

Table A5.2 Palmer Drought Index

Index Value Condition

0.49 to -0.49 Near Normal

0.50 to 0.00 Incipient dry spell

-1.00 to- 1.99 Mild drought

-2.00 to -2.99 Moderate drought

-3.00 to -3.99 Severe drought

-4.00 or less Extreme drought



When a moderate drought condition exists and Entergy seeks to reduce minimum releases at

Remmel Dam, Entergy will convene representatives from agencies listed in Table A5.3.

Table A5.3 Entergy Drought Contingency Plan Workgroup

Federal Energy Regulatory Commission National Weather Service

US Army Corps of Engineers, Vicksburg District Malvern Water Works

Arkansas Game & Fish Commission Kimzey Water District

Arkansas Natural Resources Commission Hot Springs Water Department

US Fish & Wildlife Service Other Non-Governmental Organizations as needed to represent recreational and property interests Arkansas Department of Environmental Quality

This workgroup will discuss existing moderate drought conditions and make recommendations,

if any, to the FERC, (and Army Corps of Engineers Vicksburg District if Lake Ouachita is affected)

for short-term modifications to instream flow requirements and/or elevation changes in Lakes

Catherine, Hamilton and Ouachita. Upon Entergy’s request and FERC approval (and Army Corps

of Engineers if Lake Ouachita is affected), the recommended short-term modifications may be

implemented. The workgroup’s original recommendations and accompanying federal agency

approvals must contain language specifying what conditions will trigger a return to “normal”

operations. It is desirable for the workgroup to contemplate recommendations and operational

responses to address a severe drought if an existing moderate drought worsens.

When a severe drought condition is determined to exist, Entergy may implement instream flow

reductions below Remmel Dam of 30% during the months of June, July and August, and by 40%

in any other month that the severe drought condition exists. Agencies on the workgroup will be

notified in writing at least 10 working days before these instream flow modifications go into

effect. In this written correspondence, Entergy will specify the conditions under which they will

return to “normal” operations. These flow and power generation responses will not require

FERC approval as they are considered conditions of Entergy’s license. Whenever the drought

condition is determined to improve from severe to moderate, the plan that was previously

approved for the moderate drought condition, (if any) shall be in effect. Whenever conditions

improve beyond a moderate drought, recommended modifications and drought contingency

plans will cease to be in effect.

Low Flow Condition

Historic period of record low flows on the Ouachita River at Arkadelphia have been described in

Section A.4 of this report. A low flow condition, as described here, represents a culmination of



circumstances which cause significant and sustained below-average flows on the Ouachita River

or its tributaries to the extent that ANRC would contemplate a declaration of . During shortage

a , watershed-level allocation would be implemented according to Title 3 Rules for the shortage

Utilization of Surface Water. Non-riparians would experience withdrawal restrictions before

riparians during allocation if a was declared. Verification of individual non-riparian net shortage

consumptive uses and a subbasin assessment would preface any restrictive action imposed by

ANRC during a declared . shortage

The Project Monitoring Action Plan (PMAP) describes conditions that must exist at multiple

locations before restrictions are considered by ANRC (PMAP is contained in the Executive Summary

section of this report). Figure A5.3 diagrams the primary factors which will influence surface

water availability in the upper Ouachita River subbasins. If deterioration of these factors

prevails, the cumulative impact could result in the implementation of drought management

planning and possible restriction. A defined low flow condition which requires restriction on

surface water withdrawals has not been quantified because: 1) there are no concentrated

clusters of registered diverters on the Ouachita River to restrict, and 2) there is not one factor

that can be measured which solely represents overall subbasin conditions. The low flow

condition, as defined by ANRC, represents a sustained, physical , as evidenced by shortage

concurrent deterioration of factors in Figure A5.3 and forecasted circumstances which cannot be

overcome through normal, routine efforts.

Figure A5.3 Factors Affecting Low Flow on Ouachita River



-Blakely Dam-

-Remmel Dam-

-DeGray Lake Dam-

City of Arkadelphia

-Project Diversion-

-Carpenter Dam-

Figure A5.4 Diagram of Ouachita River Basin Regulation

Thatcher Lock & Dam

Felsenthal Lock & Dam

The PMAP (see Executive Summary) describes the thresholds at specific locations which trigger

monitoring and management actions. The Figure A5.4 schematic shows locations of federal

projects on the Ouachita River between Lake Ouachita and the Arkansas-Louisiana state line.

As diagramed, upper Ouachita River subbasin runoff and subsequent flows downstream are

controlled largely by regulation and routing of Lake Ouachita storage. Given this situation, the

PMAP identifies multiple triggers (conditions) at multiple locations that must exist in order to

determine a . shortage



B. AGENCY COORDINATION Two meetings were held with state and federal agencies to discuss the proposed project and

potential environmental issues associated with water withdrawals from the Ouachita River.

One meeting was held at ANRC with state and federal agencies located in central Arkansas and

another meeting was held in Vicksburg MS between ANRC staff and Vicksburg District Corps of

Engineers Regulatory Division. ANRC received several comments and data regarding aquatic

species that may occur near the project intake and discharge structures on the Ouachita River.

This report will be circulated to those agencies and made public through the ANRC website.

ANRC will accept additional data or information generated from other agencies after the

provisional permit is issued. Any data received will be evaluated by ANRC to determine its

relevance to normal operation (water withdrawals) of the proposed project.

C. PERMIT CONSIDERATIONS Additional discussions of permit items are contained in the Executive Summary and other

sections of this report. This section includes some of those previously discussed items and

additional site-specific considerations.

C.1 Curtailment State water law grants authority to ANRC to allocate surface water during times of declared

shortages. During a shortage, surface water use is prioritized and allocated according to

ANRC’s Title 3 Rules for the Utilization of Surface Water. Surface water uses for sustaining

human health are reserved water rights and therefore exempt from allocation. Processes for

declaring a shortage and administrative procedures to implement allocation are contained in

ANRC’s Title 3 Rules for the Utilization of Surface Water. Specific discussion of curtailment and

potential limitation on project withdrawals are discussed in the Executive Summary,

Environmental Considerations, and Low Flow Condition sections of this report.

C.2 Length of Permit Recognition of non-riparian rights for intrabasin, interbasin, and interstate transfer of water in

Arkansas water law originated to allow diversion and transport of surface water to meet total

agricultural water needs in the delta region of the state and reduce groundwater demand and

depletion of the Mississippi alluvial aquifer. These projects were envisioned to transport large

volumes of surface water and require significant capital costs to construct, operate, and

maintain. However, many non-agricultural non-riparian water uses being permitted today vary



greatly in purpose and scale compared with the agricultural irrigation projects. One example of

a nonagricultural non-riparian permitted water use is for natural gas fracking.

The length of the non-riparian permit should reflect the need to periodically evaluate the water

use relative to permit conditions, current surface water availability, and any impacts to

environmental resources through normal operation of projects. Water use for natural gas

fracking is very dynamic, i.e. water transported from single withdrawal point to many “end-use”

locations and multiple projects simultaneously withdrawing water from small drainage basins-

makes it prudent to reevaluate more frequently permits issued for this water use sector when

compared to single, permanently located projects which are not likely to change withdrawal

quantities or water use locations.

Uncertainties related to surface water availability for this proposed project are relatively low.

The project will have a fairly constant withdrawal rate and the withdrawal location is not

expected to change (permanent) once the project becomes operational. For these reasons,

permit reevaluation and renewal is recommended to occur every 10 years.

C.3 Site-Specific Gaging The permittee or facility operator may be required to install a gaging apparatus on the Ouachita

River at the point of project diversion if deemed necessary by ARNC. The gaging apparatus will

be used to verify river conditions at the point of diversion and govern withdrawals during

allocation if implemented. Specifications for gaging capability will be determined after

environmental (federal) regulatory processes are complete and any additional data relevant to

normal operation of the project is identified.

C.3 Reporting Requirements The permittee or diversion facility operator is required to maintain a monitoring system capable

of reporting instantaneous and cumulative project withdrawals. Instantaneous reporting may

be required during evaluation of low flows and conditions. The Project Management shortage

Action Plan (PMAP) identifies conditions that could result in a . shortage

The permittee is responsible for reporting the project’s annual water use according to ANRC’s

water use registration procedures. Procedures for water use registration can be obtained from

ANRC’s Conservation Division.

City of Arkadelphia - · PDF fileFigure A5.3 Primary Factors Affecting Low Flow on Ouachita...

Documents

Transcript of City of Arkadelphia - · PDF fileFigure A5.3 Primary Factors Affecting Low Flow on Ouachita...