Chapter 2: Surface Water Importation and Delivery Systems ______

Table of Contents Abstract______4 Plan Summary ______4 Section 1: Formulation and Comparison of Alternatives ______6 No Action______6 Actions ______6 Action 1: Investigate Potential Water Sources______6 Use the River as a water source. ______6 Use the Yazoo River System as a water source. ______6 Use the existing rivers and streams as a water source.______7 Use of a well field close to the Main Line Levee as a water source ______7 Action 2: Develop a surface water importation and delivery system to get the water to on-farm delivery points.______7 Bolivar County: Water from the Mississippi River was pumped into the Bogue Phalia. ______7 Sunflower County: Pump water from the Mississippi River into the Sunflower. ______11 Alternate Sunflower and Leflore Counties: Bring water from the Tallahatchie River into the Quiver.13 Humphreys County: Pump water from the Mississippi River into the Sunflower River. ______15 Section 2: Environmental Impacts ______18 Effects of Action 1: Investigate Potential Water Sources ______18 Use the Mississippi River as a water source ______18 Use the Coldwater, Tallahatchie, Yazoo River System as a water source ______18 Use the existing rivers and streams as a water source ______18 Use of a well field close to the Mississippi River levee as a water source______18 Effects of Action 2: Develop a surface water importation and delivery system to get the water to on- farm delivery points. ______19 Bolivar County: Water from the Mississippi River is pumped into the Bogue Phalia. ______19 Sunflower County: Pump water from the Mississippi River into the Sunflower River for use in Sunflower County. ______19 Alternate Sunflower County: Bring water from the Tallahatchie River into the Quiver River for use in Sunflower and Leflore Counties. ______19 Humphreys County: Pump water from the Mississippi River into the Sunflower River. ______20 Benefit to Cost Considerations______20 Effects of Alternative Plans ______20 References Cited ______22 Appendix A: Bolivar County On-Farm Delivery Systems______23 Appendix B: Sunflower County On-Farm Delivery Systems ______24 Appendix C: Study Area 5 On-Farm Delivery Systems______25

Page 2 of 25

List of Tables Table 1: Monthly flow values for the Yazoo River at Greenwood, Mississippi.______7 Table 2: Acres and volume supplied by on-farm delivery system for Bolivar County.______8 Table 3: Construction for Bolivar County with Mississippi River as water source. ______10 Table 4: Construction for Bolivar County with a series of well fields as a water source. ______10 Table 5: Acres and volume supplied by on-farm delivery system for Sunflower County. ______11 Table 6: Construction for Sunflower County, Sunflower County.______11 Table 7: Importation system to move water from the Mississippi River to Area 3 and Area 5. ______12 Table 8: Importation system to move water from well fields to the Sunflower River. ______12 Table 9: Importation system to move water from the Tallahatchie River to the Quiver.______13 Table 10: Acres and volume supplied by on-farm delivery system for Humphreys County. ______15 Table 11: Construction for Humphreys County. ______16 Table 12: Acres supplied by underground lines & pumps in Bolivar County. ______23 Table 13: Acres supplied by underground lines & pumps in Sunflower County. ______24 Table 14: Acres supplied by underground lines & pumps in Study Area 5. ______25

List of Figures Figure 1: with study areas delineated. ______5 Figure 2: Bolivar County, Bogue Phalia surface water delivery system.______9 Figure 3: Sunflower County, Sunflower River surface water delivery system ______14 Figure 4: Sunflower River, Humphreys, Washington Counties, surface water delivery system ______17

Page 3 of 25

Abstract The USDA NRCS Mississippi Delta Comprehensive, Multipurpose Water Resource Plan, Study Phase was initiated in 1993 in response to leadership concerns about the viability of agricultural industry and maintenance of water quality in light of decreasing water supplies, both groundwater and surface water. The request to determine the feasibility of stabilizing the groundwater levels in the Mississippi River Alluvial Aquifer (Aquifer) came from the YMD Joint Water Management District (YMD) and Delta Soil and Water Conservation Districts (SWCD). The Aquifer that supplies water for approximately 13,000 currently used agricultural wells in the Delta, is experiencing long term declines in groundwater levels of approximately 100,000 acre-feet per year. This part of the study proposes that a surface water delivery system be installed to replace groundwater pumping and reduce this overdraft.

The Mississippi Department of Environmental Quality (DEQ) in cooperation with the U.S. Geological Survey (USGS) developed a groundwater model for the Aquifer in the mid 1980s. The model predicted that continued pumping from the Aquifer would result in significant water level declines at current and projected water use rates.1 Continued analysis of the Aquifer by USGS identified five primary areas of groundwater decline. Areas representing three of these decline locations were Bolivar County on the Bogue Phalia near the town of Shaw, Sunflower County on the Sunflower River, Humphreys and Washington Counties on the Sunflower River and Sunflower and Leflore Counties on the Quiver River. (Figure 1) Groundwater storage decreased 843, 782 and 157 acre feet per square mile in these areas respectively between 1980 and 1994. The potential for increased and accelerated declines in these areas exists due to increases in pumping.2

Plan Summary Actions involve planning the installation of a surface water delivery system potentially consisting of a combination of new canals, current streams and rivers, drainage canals and on-farm underground lines. The goal is to stop the 100,000 acre-feet per year overdraft and additionally to have a positive impact on receiving water quality.

Page 4 of 25

Figure 1: Mississippi Delta with study areas delineated.

Page 5 of 25

Section 1: Formulation and Comparison of Alternatives

No Action A no action alternative provides no method to balance Aquifer withdrawals and inputs, no conservation practices, structural or management, for improved use of existing water sources, no development of new water supplies, and no environmental protection for wildlife, fisheries, or water quality.

Major uses of water in the Delta, irrigation, industry, municipal, wildlife and fisheries would continue with no action to stop Alluvial Aquifer overdrafting. However; the potential to permanently harm the Alluvial Aquifer by water mining, which collapses sand and gravel layers exists with a no action option. At first, groundwater costs would increase greatly as the Alluvial Aquifer lost productivity and wells had to be placed at increasingly deeper levels within the aquifer. Eventually, increasing constraints on industrial, municipal, and agricultural development would occur as readily available water supplies dwindled. Wildlife and fisheries habitat would continue to be lost and permitted effluents would fail to be adequately diluted as baseflows in rivers decreased.

Actions The actions needed and major tools to be developed to help solve the problems documented in this study include the following.

1. Investigate potential water sources. 2. Develop a surface water importation and delivery system to get the water to on-farm delivery points. 3. Develop typical designs for delivery of water from importation channels to specific fields for irrigation. 4. Develop costs for installation and operation and maintenance.

Details of these actions are discussed in the following paragraphs.

Action 1: Investigate Potential Water Sources

Use the Mississippi River as a water source. The Mississippi River represents a significant if not unlimited water supply on the western side of the Delta. A pumping plant could be constructed between the towns of Friars Point and Delta to supply water to the Big Sunflower River. A second pumping plant could be constructed near Deeson to deliver water to the Bogue Phalia.

The use of the Mississippi River as a source of water for the interior Delta is currently opposed by the USFWS due to the presence of the zebra mussel (Dreissena polymorpha). 3 The absence of the mussel in the Sunflower River system could prevent the use of Mississippi River water to augment the Sunflower River for fear of introducing a foreign species. Filtration is possible, but not feasible for the quantities of water required. With the rapid spread of the zebra mussel it may be only a matter of time before this is no longer an issue. Use the Yazoo River System as a water source. The Yazoo River on the eastern side of the Delta represents a potential source of water for irrigation. Several rivers originate outside the Delta, the Coldwater, Tallahatchie, Yalobusha and Yacona, and empty into the Yazoo. A possible limitation to use of this water source is the COE’s responsibility in managing the flood control reservoirs that also feed this system. A compatible use plan is possible. There is

Page 6 of 25

sufficient flow to maintain the river above its critical water level during the irrigation and low flow periods (Table 1). Withdrawals for irrigation would be planned to avoid taking enough water to jeopardize the river. The reservoirs serve to reduce extremely high flows and extend mid-level flows. This design seems compatible with use during the growing season. Table 1: Monthly flow values for the Yazoo River at Greenwood, Mississippi.4 Value April May June July August September October cubic feet per second Critical 5,160 4,230 7,355 4,065 2,260 5,200 7,035 Average 14,175 12,935 10,740 9,260 8,605 8,435 8,755

Use the existing rivers and streams as a water source. The Sunflower River, Bogue Phalia, Quiver River, , and Steele Bayou are the major internal Delta streams. Flows in these systems are primarily from runoff events, either storms or irrigation return flows. Flows are unregulated and vary both spatially and temporally in quantity of water available for all water uses. They are therefore, undependable as water sources. Use of a well field close to the Main Line Mississippi River Levee as a water source Well fields located within approximately one mile of the Mississippi River levee are recharged directly by the Mississippi River and should not cause declines in the Alluvial Aquifer. Work done by MSDEQ indicates that the river does not directly influence wells at distances greater than about 1 mile from the levee. 5 The authors caution that the geology of the site for a specific project should be examined before making a final site selection due primarily to the potential presence or absence of clay layers and confined or unconfined aquifer conditions. Therefore, geological investigations would be done prior to site selection.

Action 2: Develop a surface water importation and delivery system to get the water to on-farm delivery points. Water delivery from major sources would be through a canal system that could have a myriad of configurations based on the distance from the source, complexity of agricultural development, amounts of water needed to replace groundwater use, and maintenance of flood control capacity. Possible systems vary in cost and complexity from using existing river channels with delivery canals originating at the river to digging an all new canal system. Engineers designed each system so that the pumped flow volume was excavated from the channels involved. This insured that there would be no change in the carrying capacity of any channel, stream, or river. This report examined three importation and on-farm delivery scenarios.

Bolivar County: Water from the Mississippi River was pumped into the Bogue Phalia. Water originated at the Mississippi River near Deeson, Mississippi where it was pumped into the Bogue Phalia. A series of three delivery laterals were planned to deliver water from the Bogue Phalia to groundwater irrigated fields within about 2 miles of the Bogue Phalia on the west side. (Figure 2)

An area representing Bolivar County was chosen for intensive water delivery analysis. This area was approximately 5 miles west of Shaw, MS between Highways 446 and 448. (See Figure 1) The area covered about 13,020 acres with 10,680 acres permitted for irrigation. There were 115 permitted withdrawal points with a permitted water volume of 49,443 acre-feet/year. Seventy-three permits were for groundwater withdrawal at 35,514 acre-feet/year.

A maximum delivery rate of 15 gpm per acre was assumed to plan for maximum use periods such as rice flushing. Pumping plants, laterals, relifts, and pipelines were planned for this water delivery rate. A system to deliver a total of 151,500 gpm on 10,096 acres was planned for this study area. This would require a channel flow in the Bogue Phalia of about 340 cfs. (Table 2) A series of three laterals stemming from the

Page 7 of 25

Bogue Phalia would be constructed on currently farmed ground to take the water from the Bogue to on- farm delivery locations. Underground lines from the delivery location to the field would also be installed at locations on currently farmed ground. Table 2: Acres and volume supplied by on-farm delivery system for Bolivar County. Water Source Acres GPM CFS Lateral A 3,334 50,010 111 Lateral B 1,993 29,895 67 Lateral C 2,600 39,000 87 Bogue Phalia 2,169 32,535 73 System Total 10,096 151,440 338

Estimated water savings would be from 20,000 acre-feet/year based on an average crop use of 2 acre- feet/year.

The well field scenario for Bolivar County assumed that the same channels as those used for Mississippi River water would be used for importation. The channel capacity could vary depending upon well field location. It may be possible to locate fields in a manner to reduce channel work on the Bogue Phalia. This could lower both costs and environmental impacts. The system was designed to deliver a maximum amount of water to all wells at the same time. Model analysis of the system to optimize size could potentially reduce both costs and environmental impacts.

Importation from the Mississippi River and on-farm delivery of water for the Bogue Phalia in Bolivar county average annual costs were $626,400 with benefits of $1,736,900. The benefit cost ratio was 2.7:1 making this option economically feasible.

Supplying water from a well field and on-farm delivery of water for the Bogue Phalia system Bolivar county average annual costs were $685,000 with benefits of $1,736,900. The benefit cost ratio was 2.5:1 making this option economically feasible.

Operation, maintenance, and replacement costs for the importation system for Bolivar County were estimated at $41,200 per year with power cost for pumping at $58,800.

Water costs at $726,400 for 20,000 acre feet were $36 per acre foot.

Page 8 of 25

Figure 2: Bolivar County, Bogue Phalia surface water delivery system.

Page 9 of 25

Table 3: Construction for Bolivar County with Mississippi River as water source. Component Amount Unit Unit Cost Total Cost Delivery System Channel Excavation 400,000 cu yd 1 400,000 State Aid Road Crossings 3 each 80,000 240,000 County Road Crossings 4 each 60,000 240,000 Channel/present drain Crossings 8 each 16,000 96,000 Pump (Lateral A) 1 LS 773,605 773,605 Pump (Lateral B) 1 LS 491,071 491,071 Pump (Lateral C) 1 LS 617,884 618,884 Subtotal 2,859,560 On-Farm System Underground Pipelines 24 inch 97,320 LF 16.50 1,605,780 18 inch 8,200 LF 9.00 73,800 Pumps for Pipeline 18 each 13,500 243,000 Pumps at Water Supply 31 each 13,500 418,500 Subtotal 2,341,080 Import System Hydraulic Dredge (Bogue Phalia) 400,000 cu yd 3.50 1,400,000 Pumping Plant @ Mississippi River 1 LS 1,486,667 1,486,667 State Hwy. 32 Crossing 1 LS 278,800 278,800 State Hwy. 1 Crossing 1 LS 278,800 278,800 Subtotal 3,444,267 Total Cost of System $8,644,907

Table 4: Construction for Bolivar County with a series of well fields as a water source. Component Amount Unit Unit Cost Total Cost Delivery System Channel Excavation 400,000 cu yd 1 400,000 State Aid Road Crossings 3 each 80,000 240,000 County Road Crossings 4 each 60,000 240,000 Channel/present drain Crossings 8 each 16,000 96,000 Pump (Lateral A) 1 LS 773,605 773,605 Pump (Lateral B) 1 LS 491,071 491,071 Pump (Lateral C) 1 LS 617,884 618,884 Subtotal 2,859,560 On-Farm System Underground Pipelines 24 inch 97,320 LF 16.50 1,605,780 18 inch 8,200 LF 9.00 73,800 Pumps for Pipeline 18 each 13,500 243,000 Pumps at Water Supply 31 each 13,500 418,500 Subtotal 2,341,080 Import System Hydraulic Dredge (Bogue Phalia) 400,000 cu yd 3.50 1,400,000 wells & pumps for well field 62 each 37,000 2,294,000 State Hwy. 32 Crossing 1 LS 278,800 278,800 State Hwy. 1 Crossing 1 LS 278,800 278,800 Subtotal 4,251,600 Total Cost of System $9,452,240

Page 10 of 25

Sunflower County: Pump water from the Mississippi River into the Sunflower. Water originates at the Mississippi River near Friars Point, Mississippi where it is pumped into the Sunflower River. A new delivery canal approximately 4 miles long will be built to take water from the Sunflower River into the Quiver River. Water will be lifted downstream into a new 9.7-mile canal that will connect to existing surface drainage (manmade) and Pecan Bayou. Several new east-west laterals will be developed to deliver water to all groundwater irrigated fields. (Figure 3)

Sunflower County study area lies approximately 4 miles south of Ruleville, MS on Highway 49 to the town of Sunflower and from the Sunflower River on the west to the Sunflower-Leflore county line on the east. (See Figure 1) The area covers about 41,300 acres with about 26,750 acres irrigated, and 18,350 of the irrigated acres are from groundwater wells. There are 308 permitted withdrawal points with a permitted water volume of 106,504 acre-feet/year. Two hundred and eighty three permits are for groundwater withdrawal at 99,094 acre-feet/year.

A maximum 15 gpm per acre was assumed to plan for maximum use periods such as rice flushing. Pumping plants, canals, laterals, relifts, and pipelines were planned for this water delivery rate. A series of eight laterals constructed on currently farmed ground would take the water from either the Sunflower River or the new delivery canal to on-farm delivery locations. Building these laterals would require 217,764 cubic yards of excavation. Underground lines would also be installed at locations on currently farmed ground. This system would deliver a total of 272,655 gpm on 18,177 acres. This would require about 600 cfs in the river channel. (Table 5) Table 5: Acres and volume supplied by on-farm delivery system for Sunflower County. Water Source Acres GPM CFS Lateral A 682 10,230 23 Lateral B 957 14,355 32 Lateral C 1,653 24,795 55 Lateral D 1,284 19,260 43 Lateral E 1,219 18,285 41 Lateral F 841 12,615 28 Lateral G 1,264 18,960 42 Lateral H 1,395 20,925 47 New Delivery Canal 6,339 95,085 211 Sunflower River 2,543 38,145 85 System Total 18,177 272,655 607

Water savings were estimated at 36,250 acre feet using 2 acre feet per cropping season.

The well field scenario assumes that these same channels would be used for importation. The channel capacity could vary depending upon well field location. It may be possible to locate fields in a manner to reduce channel work on the Sunflower River. This could lower both costs and environmental impacts. Well fields would need to supply 600 cfs for Area 3 and 200 cfs for Area 5. This would require a total of 144 wells. The system was designed to deliver a maximum amount of water to all wells at the same time. Model analysis of the system to optimize size could reduce costs as well as environmental impacts. Operation, maintenance, and replacement costs for the importation system for Study Areas 3 & 5 were estimated at $214,000 per year with power cost for pumping at $117,600. Table 6: Construction for Sunflower County, Sunflower County.

Page 11 of 25

Component Amount Unit Unit Cost Total Cost Delivery System Channel Excavation 1,379,000 cu yd 1 1,379,000 County Road Crossings 9 each 60,000 540,000 Field Road Crossings 6 each 30,000 180,000 Channel/present drain Crossings 7 each 16,000 112,000 Pump (Lateral A) 1 LS 154,721 154,721 Pump (Lateral B) 1 LS 221,991 221,991 Pump (Lateral C) 1 LS 369,985 369,985 Pump (Lateral D) 1 LS 295,988 295,988 Pump (Lateral E 1 LS 295,988 295,988 Pump (Lateral F) 1 LS 201,810 201,810 Pump (Lateral G) 1 LS 295,988 295,988 Pump (Lateral H) 1 LS 316,169 316,169 Subtotal 4,363,640 On-Farm System Underground Pipelines 24 inch 195,000 LF 16.50 3,217,500 18 inch 33,000 LF 9.00 297,000 15 inch 8,450 LF 6.00 50,700 12 inch 9,300 LF 4.50 41,850 Pumps for Pipeline 44 each 13,500 594,000 Pumps at Water Supply 19 each 13,500 256,500 Subtotal 4,457,550 Total Cost of System $8,821,190 Table 7: Importation system to move water from the Mississippi River to Area 3 and Area 5. Component Amount Unit Unit Cost Total Cost Importation System Hydraulic Dredge (BSR) 7,258,000 cu yd 3.50 25,403,000 Channel Excavation BSR Hwy. 1 to MSR 296,300 cu yd 1 296,300 Pumping Plant @ MSR 1 LS 5,536,321 5,536,321 Pumping Plant @ BSR into import channel 1 LS 3,592,218 3,592,218 State Hwy. 1 Crossing 1 LS 278,800 278,800 State Aid Road Crossing 1 LS 80,000 80,000 County Road Crossing 1 LS 60,000 60,000 Total Cost of System $35,246,639

Table 8: Importation system to move water from well fields to the Sunflower River. Component Amount Unit Unit Cost Total Cost Importation System Hydraulic Dredge (BSR) 7,258,000 cu yd 3.50 25,403,000 Channel Excavation BSR Hwy. 1 to MSR 296,300 cu yd 1 296,300 wells and pumps for well fields 144 each 37,000 5,328,000 Pumping Plant @ BSR into import channel 1 LS 3,592,218 3,592,218 State Hwy. 1 Crossing 1 LS 278,800 278,800 State Aid Road Crossing 1 LS 80,000 80,000 County Road Crossing 1 LS 60,000 60,000 Total Cost of System $35,038,318

Page 12 of 25

Alternate Sunflower and Leflore Counties: Bring water from the Tallahatchie River into the Quiver. This alternative was not investigated as fully as the previous option. It remains in the report to be studied in more detail in the next phase of this study at the sponsor’s request.

Imported water would be transferred from the Tallahatchie River via a new channel to Cassidy Bayou that would require no work to carry the water. A second new channel would be needed to get to Sandy and Parks Bayous which would require some clean out to carry the water to the Quiver River. The potential to impact wetlands would be investigated and compliance regulations would be upheld.

An on-farm delivery scenario was not developed for this alternative. Table 9: Importation system to move water from the Tallahatchie River to the Quiver. Component Amount Unit Unit Cost Total Cost Importation System New channel, Tallahatchie to Cassidy Bayou 132,000 cu yd 2.00 264,000 Field road crossing 1 LS 30,000 30,000 County road crossing 1 LS 60,000 60,000 New channel, Cassidy Bayou to Sandy Bayou 158,400 cu yd 2.00 316,800 State Hwy. 49 Crossing 1 LS 278,800 278,800 Railroad Crossing 1 LS 96,000 96,000 County Road Crossing 1 LS 60,000 60,000 Channel improvements, Sandy & Parks Bayou 350,577 cu yd 2.00 701,200 Field road crossing 2 LS 30,000 60,000 County road crossing 2 LS 60,000 120,000 Weirs or pumps, rough estimates 3 LS 500,000 1,500,000 Total Cost of System $3,486,800

Page 13 of 25

Figure 3: Sunflower County, Sunflower River surface water delivery system

Page 14 of 25

Humphreys County: Pump water from the Mississippi River into the Sunflower River. Water originated at the Mississippi River near Friars Point, Mississippi where it was pumped into the Sunflower River. A series of three new delivery canals would be built to take water from the Sunflower River into existing surface drainage ditches, manmade, for relift onto all groundwater irrigated fields. (Figure 4)

Humphreys County study area lies approximately 5 miles west of Belzoni, MS South of Highway 12. (See Figure 1) The designated study area covers about 17,000 acres with 7,770 acres irrigated. There were 67 permitted withdrawal points with a permitted water volume of 29,240 acre-feet/year. Fifty-eight were groundwater permits with a permitted water volume of 25,231 acre-feet/year.

A maximum delivery rate of 15 gpm per acre was assumed to plan for maximum use periods such as rice flushing. Pumping plants, canals, laterals, relifts, and pipelines were planned for this water delivery rate. A system to deliver a total of 96,933 gpm on 6,459 acres was planned for this study area. This would require about 200 cfs in the river channel. (Table 9) A series of three laterals stemming from the Sunflower River would be constructed on currently farmed ground to take the water from the Bogue to on-farm delivery locations. Underground lines from the delivery location to the field would also be installed at locations on currently farmed ground. Laterals would partially follow existing drainage district ditches or streams and require some excavation.

Table 10: Acres and volume supplied by on-farm delivery system for Humphreys County. Water Source Acres GPM CFS Lateral D 2,201 33,091 74 Lateral E 567 8,495 19 Lateral F 2,015 30,225 67 Sunflower River 1,676 25,122 56 System Total 6,459 96,933 216

Water savings would be 13,000 acre feet at 2 acre feet per season.

Page 15 of 25

Table 11: Construction for Humphreys County. Component Amount Unit Unit Cost Total Cost Delivery System Channel Excavation 116,000 cu yd 1 116,000 State Aid Road Crossing 2 each 80,000 160,000 County Road Crossings 1 each 60,000 60,000 Field Road Crossings 1 each 30,000 30,000 Channel/present drain Crossings 6 each 16,000 96,000 Pump (Lateral D) 1 LS 517,979 517,979 Pump (Lateral E) 1 LS 141,267 141,267 Pump (Lateral F) 1 LS 517,979 517,979 Subtotal 1,639,225 On-Farm System Underground Pipelines 24 inch 40,550 LF 16.50 669,075 18 inch 18,700 LF 9.00 168,300 15 inch 5,800 LF 6.00 34,800 12 inch 7,950 LF 4.50 35,775 10 inch 3,250 LF 3.50 11,375 Pumps for Pipeline 19 each 13,500 256,500 Pumps at Water Supply 16 each 13,500 216,000 Subtotal 1,391,825 Total Cost of System $3,031,050

The importation systems for Area 5 were presented in Tables 5 and 6. Operation, maintenance, and replacement costs for the importation system for Study Areas 3 & 5 were estimated at $214,000 per year with power cost for pumping at $117,600.

Water sources considered were the Mississippi River and the Coldwater-Tallahatchie-Yazoo River system. Importation from the Mississippi River and on-farm delivery of water for the Sunflower River to demonstration areas in Sunflower, Humphreys, and Washington counties average annual costs were $3,412,800 with benefits of $6,387,900. Benefits were calculated based on a total loss of the Alluvial Aquifer resulting in the loss of groundwater supplies. Benefits relate only to farm income. No peripheral industries were included. The benefit cost ratio was 1.9:1 making this option economically feasible. Costs and benefits of bringing water from well fields are for all practical purposes equal to Mississippi River costs and benefits.

The Sunflower River options potential surface water savings is approximately 50,000 acre feet at $3,800,000 or $76 per acre foot.

Page 16 of 25

Figure 4: Sunflower River, Humphreys, Washington Counties, surface water delivery system

Page 17 of 25

Section 2: Environmental Impacts

Effects of Action 1: Investigate Potential Water Sources

Use the Mississippi River as a water source The Mississippi River runs the entire western length of the Delta. It has the potential to supply large volumes of water for use in this area.

USFWS has expressed a concern that pumping water from the Mississippi River would hasten the invasion of the Zebra mussel (Dreissena polymorpha) into Mississippi's internal rivers and streams. The zebra mussel is considered to be a macrofouler because it quickly colonizes new areas and rapidly achieves high population densities.

Overall, Mississippi River water quality is good enough to be used in Delta streams and rivers without decreasing the existing water quality.

Use the Coldwater, Tallahatchie, Yazoo River System as a water source The Coldwater, Tallahatchie, Yazoo River System on the eastern side of the Delta represents a potential source of water for irrigation. Several rivers originate outside the Delta, the Coldwater, Tallahatchie, Yalobusha and Yocona, and empty into the Yazoo in the Delta near Greenwood, MS. A possible limitation to use of this water source is the COE’s responsibility in managing the flood control reservoirs that also feed this system. A compatible use plan is possible. There is sufficient flow to maintain the river above its critical water level during the irrigation and low flow periods. Withdrawals for irrigation would be planned to avoid taking enough water to jeopardize the river. The reservoirs serve to reduce extremely high flows and extend mid-level flows. This design seems compatible with use during the growing season.

Overall, the water quality in this system was good enough to be used in Delta streams and rivers without decreasing the existing water quality.

Use the existing rivers and streams as a water source The Sunflower River, Bogue Phalia, Quiver River, Deer Creek, and Steele Bayou are the major internal Delta streams. Flows in these systems are primarily from runoff events, either storms or irrigation return flows. Flows are unregulated and vary both spatially and temporally in quantity of water available for all water uses. They are therefore, undependable as water sources.

Use of a well field close to the Mississippi River levee as a water source Well fields located within approximately one mile of the Mississippi River levee are recharged directly by the Mississippi River and should not cause declines in the Alluvial Aquifer. Water from these wells would be naturally filtered by passage through the aquifer and would be of better quality than existing stream waters. There is potential for water of this quality to improve current stream water conditions. The possible contamination of internal streams from Zebra mussels would be eliminated.

Use of this water poses no negative impacts on the existing stream water quality.

Page 18 of 25

Effects of Action 2: Develop a surface water importation and delivery system to get the water to on-farm delivery points.

Bolivar County: Water from the Mississippi River is pumped into the Bogue Phalia. Imported water would be delivered via the existing Bogue Phalia channel. Approximately 400,000 cubic yards of material would need to be hydraulically dredged from the upper Bogue Phalia channel. This excavation volume was calculated assuming that the channel flow elevation would not exceed its design capacity elevation as per COE routings when irrigation water was added. This assumption was made to provide maximum channel capacity. This work would require an in-depth investigation of the exact location, extent of the work, and disposal of the sediments before it could be implemented due to its potential to alter the river channel and riparian area. The potential to impact wetlands would be investigated and compliance regulations would be upheld.

Planned flows would occur when the rivers are naturally low which would minimize the potential for adverse impacts on flood control.

A series of three laterals constructed on currently farmed ground would take the water from the Bogue to on-farm delivery locations. Underground lines would also be installed at locations on currently farmed ground. Laterals would follow existing drainage district ditches or intermittent streams and would require 374,300 cubic yards of excavation. Although these laterals would be on currently farmed ground, the potential to impact wetlands would be investigated and compliance regulations would be upheld.

Sunflower County: Pump water from the Mississippi River into the Sunflower River for use in Sunflower County. Imported water would be delivered through the existing Sunflower River channel with 7,258,00 hydraulic dredge work and 296,000 cubic yards channel work and through a new delivery canal that would require 1,379,000 cubic yards of excavation. Although this canal would be constructed primarily on currently farmed ground, the potential to impact wetlands would be investigated and compliance regulations would be upheld.

A series of eight laterals constructed on currently farmed ground would take the water from either the Sunflower River or the new delivery canal to on-farm delivery locations. Building these laterals would require 217,800 cubic yards of excavation. Underground lines would also be constructed at locations on currently farmed ground. Although this channel work would occur on currently farmed ground, the potential to impact wetlands would be investigated and compliance regulations would be upheld.

Alternate Sunflower County: Bring water from the Tallahatchie River into the Quiver River for use in Sunflower and Leflore Counties. This alternative was not investigated as fully as the previous option. It remains in the report to be studied in more detail in the next phase of this study at the sponsor’s request.

Imported water would be transferred from the Tallahatchie River via a new channel to Cassidy Bayou that would require no work to carry the water to a second new channel to get to Sandy and Parks Bayous which would require some clean out to carry the water to the Quiver River. The potential to impact wetlands would be investigated and compliance regulations would be upheld.

An on-farm delivery scenario was not developed for this alternative.

Page 19 of 25

Humphreys County: Pump water from the Mississippi River into the Sunflower River. Imported water could be delivered through the existing Sunflower River channel without any channel work. Two hundred cfs was historically the flow volume of the Sunflower River at low flow. Therefore, planned flows that also occur when the rivers are naturally low and would have a minimum potential to adversely impact flood control.

A series of three laterals constructed on currently farmed ground would take the water from the Sunflower River to on-farm delivery locations. Underground lines would also be installed at locations on currently farmed ground. Laterals would partially follow existing drainage district ditches or intermittent streams and would require 116,000 cubic yards of additional excavation. Although these laterals would be on currently farmed, the potential to impact wetlands would be investigated and compliance regulations would be upheld.

Benefit to Cost Considerations Water sources considered for the Sunflower River were the Mississippi River well fields. Importation from the Mississippi River and on-farm delivery of water for the Sunflower River to demonstration areas in Sunflower, Humphreys, and Washington counties average annual costs were $3,412,800 with benefits of $6,387,900. Benefits were calculated based on a total collapse of the Alluvial Aquifer resulting in the loss of groundwater supplies. Benefits relate only to farm income. No peripheral industries were included. The benefit cost ratio was 1.9:1 making this option economically feasible. Operation, maintenance, and replacement costs for the importation system for the Sunflower River were estimated at $214,000 per year with power cost for pumping at $117,600.

Importation from the Mississippi River and on-farm delivery of water for the Bogue Phalia system to a demonstration area in Bolivar county average annual costs were $626,400 with benefits of $1,736,900. The benefit cost ratio was 2.7:1 making this option economically feasible. Operation, maintenance, and replacement costs for the importation system for the Bogue Phalia were estimated at $41,200 per year with power cost for pumping at $58,800.

Importation of water from the Coldwater-Tallahatchie-Yazoo system into the Quiver River average annual costs were $268,800 with benefits of $370,200. The benefit cost ratio was 1.4:1 making this option economically feasible. Operation, maintenance, and replacement costs for the importation system to the Quiver River were estimated at $16,100 without pumping costs.

Effects of Alternative Plans Annual benefits, which would result from the construction of these water delivery systems, are water supply benefits that consist of the additional water supply (measured in acre-feet) for irrigation. Futures with and without project outcomes are listed below.

1. Existing conditions: The aquifer is currently being mined at a rate of about 100,000 acre-feet per year resulting in continually declining baseflows. 2. Future without project: a) Irrigation water supplies would be limited and eventually lost. i) Agricultural industry growth will be limited. ii) potential loss of catfish acres iii) potential loss of rice acres with conversion to soybeans iv) potential loss of all row crop irrigation b) Municipal and industrial communities would be weakened by the loss of agriculturally related jobs, factories, suppliers, equipment dealers, mills, gins, etc.

Page 20 of 25

3. All Alternatives: Developing a new water supply would a) help prevent water quality related problems and insure compliance with MSDEQ NPDES permits b) provide stable baseflows for internal streams and rivers c) stabilize downstream aquatic habitats creating fish and wildlife and environmental benefits d) maintain irrigation water supplies for catfish, rice and row crops e) help maintain a healthy Delta municipal and industrial base

4. Existing conditions: The aquifer is currently being mined at a rate of about 100,000 acre-feet per year resulting in continually declining baseflows. 5. Future without project: a) Irrigation water supplies would be limited and eventually lost. i) Agricultural industry growth will be limited. ii) potential loss of catfish acres iii) potential loss of rice acres with conversion to soybeans iv) potential loss of all row crop irrigation b) Municipal and industrial communities would be weakened by the loss of agriculturally related jobs, factories, suppliers, equipment dealers, mills, gins, etc. 6. All Alternatives: Developing a new water supply would a) help prevent water quality related problems and insure compliance with MSDEQ NPDES permits b) provide stable baseflows for internal streams and rivers c) stabilize downstream aquatic habitats creating fish and wildlife and environmental benefits d) maintain irrigation water supplies for catfish, rice and row crops e) help maintain a healthy Delta municipal and industrial base

Page 21 of 25

References Cited

1 Sumner, D.M. and B.E. Wasson 1990. Geohydrology and simulated effects of large groundwater withdrawals on the Mississippi River Alluvial Aquifer in northwestern Mississippi. US Geological Survey Water Supply paper 2292. 60 pp. 2 Arthur, J. Kerry 1995. Changes in the volume of water in the Mississippi River Alluvial Aquifer in the Delta, Northwestern Mississippi, 1980-94. US Geological Survey Water-Resources Investigations report 95-4127 3 Marcy, Larry, 1995. USFWS representative at public meeting in Belzoni, MS January 25, 1995. 4 US Army Corps of Engineers, 1991. Mississippi Delta, Mississippi, Reconnaissance Report. COE, Vicksburg District, Mississippi 12074 5 Bryant, Charlotte and Sandra Dowty, 1998, Mississippi River Alluvial Aquifer interaction at specific sites in northwestern Mississippi, Proceedings of the Mississippi Water Resources Conference, 12 pp.

Page 22 of 25

Appendix A: Bolivar County On-Farm Delivery Systems

Table 12: Acres supplied by underground lines & pumps in Bolivar County. Water Source Acres GPM Lateral A Underground Lines 2292 34380 Pumps 1042 15630 Subtotal 3,334 50,010 Lateral B Underground Lines 1033 15495 Pumps 960 14400 Subtotal 1,993 29,895 Lateral C Underground Lines 2164 32460 Pumps 436 6540 Subtotal 2,600 39,000 Bogue Phalia Underground Lines 1583 23745 Pumps 586 8790 Subtotal 2,169 32,535 System Total 10,096 151,440

23

Appendix B: Sunflower County On-Farm Delivery Systems

Table 13: Acres supplied by underground lines & pumps in Sunflower County.

Water Source Acres GPM Lateral A Underground Lines 682 10230 Pumps Subtotal 682 10,230 Lateral B Underground Lines 957 14355 Pumps Subtotal 957 14,355 Lateral C Underground Lines 1320 19800 Pumps 333 4995 Subtotal 1,653 24,795 Lateral D Underground Lines 1203 18045 Pumps 81 1215 Subtotal 1,284 19,260 Lateral E Underground Lines 1219 18285 Pumps Subtotal 1,219 18,285 Lateral F Underground Lines 452 6780 Pumps 389 5835 Subtotal 841 12,615 Lateral G Underground Lines 1264 18960 Pumps Subtotal 1,264 18,960 Lateral H Underground Lines 1264 18960 Pumps 131 1965 Subtotal 1,395 20,925 New Delivery Canal Underground Lines 4973 74595 Pumps 1366 20490 Subtotal 6,339 95,085 Sunflower River Underground Lines 2410 36150 Pumps 133 1995 Subtotal 2,543 38,145 System Total 10,096 151,440

Page 24 of 25

Appendix C: Study Area 5 On-Farm Delivery Systems

Table 14: Acres supplied by underground lines & pumps in Study Area 5. Water Source Acres GPM Lateral D Underground Lines 1,781 26,791 Pumps 420 6,300 Subtotal 2,201 33,091 Lateral E Underground Lines 559 8,385 Pumps 8 110 Subtotal 567 8,495 Lateral F Underground Lines 1,406 21,091 Pumps 609 9,134 Subtotal 2,015 30,225 Sunflower River Underground Lines 772 11,576 Pumps 904 13,546 Subtotal 1,676 25,122 System Total 6,459 96,933

Page 25 of 25