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Ecological Engineering 138 (2019) 155–159

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Eco ogica Engineering

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Short communication

Restoring the F orida Everg ades Comments on the current reservoir p an for so ving harmfu a ga b oomsand restoring the F orida Everg ades

Wi iam J. Mitsch

Juliet Sproul hair for Southwest Florida Habitat Restoration, Everglades Wetland Research Park, Florida Gulf oast University, 4940 Bayshore Drive, Naples, FL 34112, USA

A R T I C L E I N F O P R E F A C E

Keywords: Wet and restoration F orida Everg ades Water qua ity Harmfu a ga b ooms Red tide Phosphorus Treatment wet ands Wet ands Rivers

This is an updated version of a review written by the author in Apri 2018 at the request of The Friends of the Everg ades, an NGO based in Miami, F orida, on a p an deve oped primari y by the South F orida Water Management District (SFWMD) to mitigate coasta po ution that has resu ted from discharges from Lake Okeechobee to the Gu f of Mexico and At antic coast ine and eventua y to “send the water south” to the F orida Everg ades instead. This EAA Reservoir project was inc uded by the U.S. Army Corps of Engineers in a 2018 U.S. Congressiona bi that was approved. In May 2019, U.S. President Dona d Trump p edged to spend $200 mi ion to begin construction of this restoration, three times the amount requested by the state of F orida. Whi e sup-ported with enthusiasm by the F orida state egis ature, the SFWMD, and some NGOs such as The Everg ades Foundation, a change in eadership in the state of F orida after November 2018 e ections and especia y in the eadership of the South F orida Water Management District (SFWMD) has ed to a renewed pub ic optimism for major improvements in water qua ity management in south F orida. It is therefore time y for this review of the advantages and shortcomings of this “EAA (Everg ades Agricu tura Area) Reservoir P an” to be wide y dis-seminated in an internationa forum such as Eco ogica Engineering to encourage discussions among scientists and engineers.

1. Intr ducti n

The F orida Everg ades restoration is now at a crucia crossroad that wi determine its ong-term success or fai ure, so I consider it prudent to make some comments on the EAA Reservoir P an as it is current y described. We were unab e to de ve into the detai s of hydro ogic mode ing performed by the South F orida Water Management District (SFWMD) re ated to this project given the short time a owed for comments and ack of support for a rigorous mode ing efort, but I am providing this hopefu y constructive critique so that the U.S. Army Corps of Engineers and the SFWMD can fne-tune the EAA Reservoir P an so that it becomes a signifcant step forward toward comp etion of a sustainab e F orida Everg ades restoration.

I frst express my support for an ambitious efort to e iminate dec-ades of sta ing with a serious “sending the water south” strategy, the mantra for a generation of those who understand the big picture of what the F orida Everg ades restoration is a about. The South F orida Water Management District c aimed that the EAA Reservoir project wi — when used in conjunction with other existing and p anned projects — reduce the number of damaging discharge events from Lake Okeechobee to the St. Lucie and Ca oosahatchee rivers by 63% and increase the fow going south to the Everg ades and F orida Bay by 76%

from 0.26 to 0.46 bi ion m3/year (160,000 to 370,000 acre-ft/year). But if this p an resu ts in po utants, particu ar y phosphorus and

nitrogen, getting into greater Everg ades water conservation areas (WCAs) and south to the Everg ades Nationa Park, or deve ops an unsustainab e, un-eco ogica and/or simp y po uted reservoir to manage in perpetuity, we wi regret the day we said OK “just to spend the money.” I am not assured from what I see written so far that this project is proper y focused on what is important—sending c ean water to the greater F orida Everg ades. If ever there was a time for an eco- ogica engineering and not just civi engineering approaches to ead the Everg ades restoration, it is now.

2. Backgr und

One-third of the origina F orida Everg ades was drained during the 20th century and converted into productive agricu tura and (EAA), most y for sugar farms. Eventua y $1 to 2 bi ion do ars of F orida taxpayers’ money was spent to create and maintain treatment wet ands (ca ed stormwater treatment areas (STA)) to treat runof rich in nu-trients from this EAA to protect the downstream Everg ades Nationa Park. The F orida Everg ades is current y in the midd e of a many-decades, mu ti-bi ion US $ restoration p an. As I stated in an editoria

https://doi.org/10.1016/j.eco eng.2019.07.009 Received 9 May 2019; Received in revised form 1 Ju y 2019; Accepted 7 Ju y 2019 0925-8574/ © 2019 Published by Elsevier B.V.

W.J. Mitsch Ecological Engineering 138 (2019) 155–159

in Ecological Engineering three years ago:

“There is current y major concern being expressed throughout F orida USA about the recent pu ses of an excessive amount of po uted farm water from the 1890-km2 sha ow and eutrophic Lake Okeechobee (a so known as “Lake O”) into the Ca oosahatchee River to the west and into the St. Lucie River to the east by the U.S. Army Corps of Engineers (Fig. 1). This is part of the scheme for managing hydro ogy in the 46,000-km2 Greater F orida Everg ades, one of the argest wet and restorations in the wor d” Mitsch (2016).

Major coasta po ution, unanticipated in the origina Everg ades restoration p an, has acce erated recent y, particu ar y in 2013, 2016, and 2018. The coasta po ution of estuaries, freshwater rivers, wet ands and even beaches has sidetracked and even threated to derai the re-storation of the F orida Everg ades that was once viewed primari y as a hydro ogic project but now has become much more focused on water qua ity. If this same Lake Okeechobee water is discharged south to the Everg ades and is not dramatica y improved in water qua ity to ow concentrations of phosphorus and nitrogen, then the project needs dramatic redesign to focus much more on water qua ity rather than on y moving massive quantities of water around annua y.

3. The plan

A current p an, referred to as C240A (Smith, 2018), ca s for sending Lake Okeechobee water to an “EAA Reservoir” to be constructed about 50 km (30 mi es) south of Lake Okeechobee with the fo owing design: A 7-m (23-foot)-deep, 4087-ha (10,100-acre) reservoir with the capa-city to store up to 300 mi ion m3 (240,000 acre-ft or 78.2 bi ion ga - ons) of excess Lake Okeechobee water (Fig. 2). The p an a so invo ves comp etion of a previous y approved 6070-ha (15,000–acre) A-1 F ow Equa ization Basin with a maximum water storage of 74 mi ion m3

(60,000 acre-feet or 20 bi ion ga ons) and the design and construction of 2630 ha (6500 acres) of sha ow treatment wet ands, sometimes re-ferred to by the SFWMD as Stormwater Treatment Areas (STAs), simi ar to the 25,600 ha (63,200 acres) of STAs a ready created or in progress

to c ean other EAA po uted stormwater prior to discharge to the Everg ades (Fig. 3).

4. C ncerns

1. My frst comment concerns the fa se expectations by the pub ic now that they see government approva s of up to $2 bi ion for this EAA project. I have frequent y heard “We the project is not perfect, but et’s do it whi e the money is there.” The vo ume of water being discharged south needs to be put in perspective; the 0.46 bi ion m3/ year (121 bi ion ga ons/year) of water eventua y being sent south to the Everg ades and F orida Bay in the EAA reservoir p an wi not so ve the estuarine po ution of the Gu f of Mexico and At antic Ocean coast ines. Fig. 1 i ustrates the Everg ades Restoration p an that I have inc uded in severa editions of my books since we frst pub ished it in the Mitsch and Jørgensen (2004) eco ogica en-gineering book 15 years ago and it continued to be pub ished in the 4th and 5th editions of “Wet ands” (Mitsch and Gosse ink, 2007, 2015). I am aware that the restoration p an shown in the 3rd pane has been changed in severa more recent pub ications and in pro-minent ocations inc uding the we -known wa maps at Corkscrew Swamp Sanctuary obby in Nap es, F orida, that now suggests there wi a ways be signifcant water fowing east and west to the coasta estuaries even when the restoration is comp ete. It is not c ear that the pub ic is aware that this subt e change in graphics represents a major change in the overa restoration goa s of the F orida Ever-g ades in the past decade.

2. To put 0.46 bi ion m3 of water per year (121 bi ion ga ons per year) in perspective, 3.1 bi ion m3 (819 bi ion ga ons) were dis-charged to the St. Lucie and Ca oosahatchee rivers in the E Nino fooding year of 2016 (Tab e 1), 6.2 times the fow expected to go south with the EAA Reservoir p an. Even in the 10- year period of 2008–2017, an average of 1.5 bi ion m3 per year (Tab e 1) is 3 times the 0.5 bi ion m3 per year that wi be sent south according to the p an.

3. There is insufcient detai on water qua ity in the p an re ative to

Fig. 1. Three-picture summary of historic, current, and restoration water fow in the F orida Everg ades as provided by the U.S. Army Corps of Engineers in the ear y 2000s (from Mitsch and Jørgensen, 2004).

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Fig. 2. Major features and map i ustrating the ocation of the proposed Everg ades Agricu tura Area (EAA) Reservoir P an in south F orida. F ow of po uted water from Lake Okeechobee wi be directed to pub ic ands south of the EAA region to a reservoir and fow-equa ization basin system with 2600 ha of treatment wet ands toward the F orida Everg ades to the south of the EAA. (Map based on one supp ied by SFWMD).

Fig. 3. I ustration of ocation of current treatment wet ands (ca ed oca y STAs or stormwater treat-ment areas) south of the EAA. There is no c ear in-dication if these wet ands wi receive doub e duty with additiona infows from the EAA Reservoir P an. Current y 25,600 ha (63,200 acres) of these wet ands have been created or are on the drawing boards to be created. Our conservative estimate is that 40,000 ha (100,000 acres) more of these treat-ment wet ands wi be needed to ensure that the EAA Reservoir P an wi be successfu .

water vo ume and fow. The fow south to the Everg ades wi in-crease by 76% from 0.26 mi ion m3/year (210,000 acre-ft/year or 68 bi ion ga on/yr) to 0.46 bi ion m3/year (370,000 acre-ft/yr or 121 bi ion ga on/yr) according to the EAA Reservoir p an (Smith, 2018). Despite the 76% increase in fow, the project shows on y an 11% increase in treatment wet ands of 2630 ha (6500 acres) to improve water qua ity direct y. I estimate an additiona minimum of

at east 17,500 ha (43,000 acres) of treatment wet ands (STAs or passive wet ands) wi be needed to treat the water fowing south and have recommended previous y that 40,000 ha (100,000 acres) shou d be set aside for treatment wet ands (Mitsch, 2016) to a ow for a safety factor of 2, a reasonab e design a owance for this type of eco ogica engineering project.

4. Further, we note that the estimated average concentration of tota

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Table 1 Freshwater discharges from Lake Okeechobee to the sea over the 10-year period 2008–2017, and annua y in 2013, 2016, 2017, and 2018.

Discharge from Lake Okeechobee 2008–2017 2013 2016 2017 2018

Discharge to Ca oosahatchee and Gu f of Mexico (×109 m3) 1.3 1.6 2.2 1.7 1.1 Discharge to St. Lucie and At antic Ocean (×109 m3) 0.2 0.6 0.9 0.6 0.4 TOTAL Discharge to the sea (×109 m3) 1.5 2.2 3.1 2.3 1.5 Equiva ent depth of Lake O discharged to sea (m)* 0.8 1.1 1.6 1.2 0.8

Discharge data from: USGS 02292010 CALOOSAHATCHEE CANAL DWS OF S-77 AT MOORE HAVEN FL. USGS 02276877 ST. LUCIE CANAL BLW S-308. *Based on Lake Okeechobee surface area of 1891 km2 (730 mi e2). Source: https://en.wikipedia.org/wiki/Lake_Okeechobee.

phosphorus fowing out of Lake Okeechobee wi be higher than the current concentrations of tota phosphorus fowing into the current STAs (SFWMD, 2018). Due to the higher fow, it is probab e that the phosphorus concentrations reaching future treatment wet ands (STAs) wi be higher than the concentrations reaching the current STAs and, in that case, wi threaten existing state and federa standards on Everg ades water qua ity.

5. The new EAA Reservoir wi not resemb e any natura feature of aquatic ecosystems in the greater F orida Everg ades in eco ogy, morpho ogy or hydroperiod. It wi in no way represent “restora-tion” of the F orida Everg ades as it sometimes being portrayed. The hydroperiods wi be wrong and exaggerated for south F orida eco ogy, simi ar to the way in which wet and hydroperiods were shifted in the Great Lakes coasta marshes with the diking of marsh hunt c ubs and conservation areas (Mitsch et a ., 2001; Mitsch and Gosse ink, 2015). The potentia amp itude of the annua hydro-periods of up to 7 m (23 feet) in the EAA reservoir is exceeded on y rare y in natura or human-created ecosystems, e.g., the Amazon River (Junk et a ., 1989) or Three Gorges Dam reservoir (Mitsch et a ., 2008). The reservoir may become a “freak ecosystem” over time, i.e., an aquatic ecosystem dissimi ar in hydro ogy and prob-ab y eco ogy to any other aquatic ecosystem in F orida.

6. Most eutrophic akes in our experience become occasiona or even permanent sources rather than sinks of nutrients—Buckeye Lake, Ohio (W.J. Mitsch, persona experience), Taihu Lake in China (Ke derman et a ., 2005), and even Lake Okeechobee (Havens and James, 2005). It is high y probab e that the EAA Reservoir wi not be a nutrient sink in most years, a though that is an assumption inc uded in this p an. Using a Vo enweider-type mode (Hejz ar et a ., 2006) in SFWMD’s Dynamic Mode for Everg ades Stormwater Treatment Area (DMSTA) mode as proof that the EAA Reservoir wi a ways be a nutrient sink is eco ogica y and hydro ogica y inaccurate and mis eading. The DMSTA mode was deve oped to eva uate mu tip e STA design a ternatives. Mode simp icity resu ted from aggregation of key variab es and processes contro ing phos-phorus storage and cyc ing (Wa ker and Kad ec, 2011). But the DMSTA has not been ca ibrated for reservoirs.

5. C nclusi ns

• The EAA Reservoir P an is considered the future heart of this recent attempt to send water south in the F orida Everg ades and is a good start of the discussion of so ving water excess and scarcity prob ems. The F orida State Legis ature and the South F orida Water Management District p an to increase the souther y fow by 76% and send an annua average of 0.45 bi ion m3 (121 bi ion ga ons) of water south to the Everg ades and F orida Bay is noteworthy.

• Neverthe ess, there is considerab e ambiguity in the p an and its mode predictions about the qua ity of the water as it enters the greater Everg ades south of the EAA Reservoir and through Miccosukee Triba ands on its way to the Everg ades Nationa Park and F orida Bay. At a minimum, approximate y 20,000 ha (50,000

acres) and hopefu y more than 40,000 ha (100,000 acres) of treat-ment wet ands (STAs) need to be created or restored in proximity to the new EAA Reservoir; 2630 ha (6500 acres) of new treatment wet ands as described in the EAA Reservoir P an wi be gross y insufcient to protect the Everg ades.

• The p an for an EAA Reservoir immediate y south of Lake Okeechobee shou d be re-examined. For examp e, purchase of farm and at a fair price coup ed with conversion of that and to treatment wet ands (perhaps as much as 60,000 ha (150,000 acres) from the 280,000 ha (700,000 acre) EAA in ieu of construction of a ~$2-bi ion EAA reservoir is a reasonab e a ternative to the re-servoir for water storage and water qua ity and shou d be examined. Additiona y, state-owned ands current y eased to agricu tura te-nants cou d be incorporated in any comprehensive review of a ter-natives. Providing treatment wet ands to achieve water qua ity goa s in the F orida Everg ades is c oser to true “restoration”; creation of arge difcu t-to-manage deep reservoirs is not. Federa acceptance of this p an needs to be conditioned with the requirement of ade-quate stormwater wet ands (STAs) and fow equa ization basins (FEBs), to mitigate the chances of fa ing short.

Ackn wledgements

I appreciate the support and encouragement provided by A an Farago and the Friends of the Everg ades (FOE) that made the origina assessment possib e. The FOE a so provided usefu editoria and content suggestions. I a so acknow dge the usefu discussion on this subject that we had with Tom Van Lent and Me odie Naja of the Everg ades Foundation. Fina y, Dr. Li Zhang gave great he p on many of the fow ca cu ations I used in this paper. The views and conc usions in this paper are mine and do not necessari y represent the views of my uni-versity, sponsor, or anyone I consu ted.

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