1

Impoundments: Research-based Alternative Management

ConceptsEd HanlonEd Hanlon, Soil & Water Concepts

Sanjay ShuklaSanjay Shukla, Hydrology and Water Quality Concepts

Marty MainMarty Main, Wildlife Research

Pam RobertsPam Roberts, Plant Pathology Research Tatiana BorisovaTatiana Borisova, Water Economics and Policy

Managing the Land to Manage the WaterManaging the Land to Manage the Water

2

Impoundments in Caloosahatchee Basin

0 20 Miles

N

EW

S

ImpoundmentsWater Use Permits

LakeOkeechobee

LaBelleClewiston

Ft. Myers

Permitted (1 inch)

DistributedPrivately

owned~1/3 have

functional wetlands

~2/3 have additional uplands

All of them leak!

3

Upland Impoundment

25

26

27

28

29

30

31

O-99 N-99 D-99 J-00 F-00 M-00 A-00 M-00 J-00 J-00 A-00 S-00 O-00 N-00 D-00 J-01

Wa

ter

leve

l (f

t N

GV

D)

0

500

1000

1500

2000

2500

3000

3500

Pu

mp

(rp

m)

or

Rai

n (

in x

100

0)

Impoundment - returnflow

Impoundment - outf low

Impoundment - w es t side

rain

C-pump

ground

dis charge

4

Water Budget for Impoundments

Pumped inflow 71 to 96%

Evapotranspiration (4 to 32%) Rain (4 to 29%)

Outflow31 – 39%

subsurface movement35 to 61%

5

Water Supply from Impoundments

Alternative Thickness (in) Description Weeks of irrigation6 Lining entire reservoir 13

6 Lining inside ditch and embankments 312 Lining inside ditch and embankments 4

3 N/A Recirculation 4

1

2

Weeks of irrigation based on average weekly use in the grove during the irrigation season

Shukla and Jaber (2006, 2005, 2004) – EDIS, ASCE Hydrol. Engg, ASCE Irrig. and Drain. Engg, and ASAE Transact.

6

• Most avian species/numbers: Wetlands

• Seasonal water levels influenced bird community changes

• Bird species/numbers increased with lower water levels (foraging habitat improved)

• Deer, hogs (panther prey): Uplands

Wildlife in Impoundments

7

• 85 avian species, resident and migratory

• 37% of native avian species• 65% of nesting birds• 5 species, state or federally

listed

8

ImpoundmentsPermitted ImpoundmentsPermitted Impoundments

Retain Stormwater (Retain Stormwater (1 inch=2 feet 1 inch=2 feet

depthdepth))

Provide HabitatProvide Habitat

Improve Water QualityImprove Water Quality

Increase retention Increase retention (store more than 1 (store more than 1 inch)inch)

Control water level in wetlands and Control water level in wetlands and ephemeral zone (berms, for ephemeral zone (berms, for example)example)

Re-use water at beginning of dry Re-use water at beginning of dry seasonseason

Additional StrategiesAdditional Strategies

9

Options for Using Water from Impoundment

Agricultural (and urban) irrigation Reduce groundwater usage

Urban/Agricultural partnershipWater quality / quantity credit trading Distributed impoundments – water supply – ASR

Encourage landowners to store water (internal drainage or external)

ASR: Aquifer Storage and Recovery

10

Recyclable Water Containment Area (RWCA)

Impoundments

• Land temporarily used to contain water for water quality and storage purposes

• Land is later returned to other uses (rotation)

RWCAs: Recycle nutrients; Store water; Release water slowly; Decrease flows to the coast

11

RWCA• 40% of water

movement is through berm to Outside Borrow Ditch

• Co-precipitation of P and organics is possible (Hanlon et al., 2007)

• Treatment by-products may be returned to crop land safely

• Proof of concept stage

12

Tailwater Recovery Systems

• Collects water on downhill side from Collects water on downhill side from agricultural operationsagricultural operations

• Pumping moves water for irrigation Pumping moves water for irrigation reusereuse

• Decreased Consumptive UseDecreased Consumptive Use• Must address Must address risk of diseaserisk of disease for for

cropscrops

13

Percentage of Pythium species causing pre- and post-emergence damping off

9%

13%

30%

35%

13%

Pythium Group FP. aphanidermatumP. myriotylumPythium spp.P. irregulare

Disease Risks

14

Disease Risks

• Slow Sand FiltrationSlow Sand Filtration– Prevents spread of pathogensPrevents spread of pathogens– Effectively removes human and Effectively removes human and

animal contaminants (fecal animal contaminants (fecal coliforms-coliforms-yuckyuck))

– Colonized by suppressive microorganisms

– Proven for commercial nursery and greenhouse operations

• Not demonstrated for vegetables, sugarcane, and field forages

15

Re-use from Current Structureswith Soil Filtration

16

Re-use from Current Structureswith Soil Filtration

17

Water Quality Credit Trading

Innovative mechanism proposed to address surface water quality

Objectives:Reduce the overall cost of meeting water quality

goals in a basinAllow individual entities flexibility in choosing

pollution abatement technologiesProvide individual entities with incentives to

innovate in the pollution abatement sphereAddress future growth in the basin while meeting

water quality goals

18

How Does Water Quality Credit Trading Work?

Pollution control costs can differ from source to source.

Overall costs of achieving pollution reduction goals in a Basin can be minimized by allowing sources to reallocate reductions according to their pollution-abatement costs.

Well-designed trading programs can achieve this allocation by harnessing the forces of the market.

19

Simplified Example

Two separate entities within a basin Each have a water discharge that

contributes to phosphorus (P) loading.

20

Simplified Example (cont.)

Trading scenario:WWTP would pay the farmer to remove an extra

unit of phosphorus at the lower cost. Payment that the WWTP makes to the farmer is

negotiated between them.

21

Challenges

Setting pollution cap / baseline for individual entities

Measuring pollution reduction credits High transaction costs of finding trading partner

and negotiating agreementEnforcing trading contract and liability issues

$P, N

22

Water Quality Credit Trading – Nationwide Perspective

Source: US EPA 2008. http://www.epa.gov/owow/watershed/trading/tradingmap.html

23

Water Quality Credit Trading – Nationwide Perspective (cont.)

US EPA:2003: Final Water Quality Trading Policy.

(http://www.epa.gov/owow/watershed/trading/finalpolicy2003.html )

2004: Water Quality Trading Assessment Handbook (http://www.epa.gov/owow/watershed/trading/handbook/ )

2007: Watershed-Based NPDES Permitting (http://cfpub.epa.gov/npdes/wqbasedpermitting/wspermitting.cfm )

USDA:2006: Water Quality Credit Trading Agreement with

US EPA (http://www.nrcs.usda.gov/news/releases/2006/usdaepawqagreement.html )

24

Water Quality Credit Trading - Florida

FDEP. 2006. Water Quality Credit Trading: A Report to the Governor and Legislature. (http://www.dep.state.fl.us/water/tmdl/docs/WQ_CreditTradingReport_final_December2006.pdf )

CS/HB 547: Water Pollution Control (http://www.myfloridahouse.gov/sections/bills/billsdetail.aspx?BillId=37955 )

Lower St. Johns River TMDL Executive Committee. 2008. Lower St Johns River Basin Management Action Plan (Draft) (http://www.dep.state.fl.us/northeast/stjohns/TMDL/tmdl_announcements.htm )

25

Potential Water Quantity Credits

If allowed by regulations:Quantity credits for reducing urban

stormwater volume?Quantity credits for alternative on-farm

stormwater use?Reduction of agricultural water pumping from ground / surface water sources?

26

Your turn…Your turn…