April 13, 2017 Page 1 Section 1 - General Comments

Section 1 - General Comments

These are general comments prepared by the South Florida Water Management District (District) in response to the draft Biological Opinion (BO) authored by the Fish and Wildlife Service on March 21, 2017 and submitted to the U.S. Army Corps of Engineers (USACE) regarding the Lake Okeechobee Regulation Schedule (LORS) and the Temporary Forward Pumps (TFP).

Administrative

1. Please review the draft BO for updates in legislation within the State of Florida, changes inmeeting schedules/occurrences, a general understanding of the roles and responsibilities ofthe State of Florida’s coordinating agencies and minor administrative items. As an example,please correct the Formal Consultation Initiation Date.

Funding

2. Please clarify the roles and responsibilities of the USACE and the District, especially as theyrelate to the draft Terms and Conditions. To implement Section 2.6.5, Monitoring andReporting Requirements, successfully, the USACE and the District may need to enter into aMemorandum of Understanding that would outline the roles and funding responsibilities forthis detailed and extensive requirement.

3. The scope of Section 2.6.5 appears to be above and beyond the needs of the FWS to regulateand enforce the BO. The breadth of the monitoring and reporting requirements take the formof a research project and are based on a broad statement: “To monitor take of snail kite nestswithin Lake Okeechobee proper, incidental to operation of the LORS and TFP, the Servicerequires a closer scrutiny of snail kite nest success or failure than that currently beingconducted by the University of Florida snail kite crew.” (page 111). Please clarify whethermonitoring requirements to ensure the recovery of the species are being filtered down to theapplicant when the FWS is the agency responsible with administering the EndangeredSpecies Act, as amended.

Policy

4. The draft BO does not acknowledge the G-207 and G-208 pumps along the northwest portionsof Lake Okeechobee, which are operated to augment water supply to the Indian Prairie Basin.However, the draft BO does reference the water supply needs of the Big Cypress Reservationas relying on LORS and TFPs. The pumps to the Indian Prairie Basin operate within the samelow elevation ranges as the TFPs.

5. The BO expresses the expectation of a five-year Department of the Army (DA) permit(referenced in several places). There is nothing that requires a permit be for a duration of fiveyears under federal law. In fact, subsequent discussions with the Corps suggested that thetimeframe would be shorter while the agencies work together through the District’s Snail KiteBiological Evaluation (2016 BE).

6. Although the District’s 2016 BE is listed as part of the draft BO’s Appendix B, DetailedConsultation History, it is not acknowledged in the body of the BO as part of the best available

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science used to assess the potential effects or included within the Literature Cited section of the BO.

7. Consultation History:

a. Page 2 – (Top Paragraph) The “Consultation History” should be a compilation of facts anddates, it should not include speculative language such as the italicized portion of the firstparagraph with reinterpretation of past FWS and USACE decisions.

b. Page 3 – October 2, 2014 – The FWS and USACE should provide the technical or legalevidence used to confirm that TFP was separable from LORS. In addition, how did theUSACE “verify whether it has the authority to require restrictions on TFP operations duringits public interest review”, if USACE only has jurisdiction over construction – as the Districtis repeatedly told in other arenas?

8. Section 2.2.2.8, Water Quality, confuses and/or is silent on water quality responsibilities andactivities in the state while implying that District is solely responsible for Lake Okeechobeewater quality (e.g. no Basin Management Action Plan, no Senate Bill 552, no mention ofFlorida Department of Environmental Protection/Florida Department of Agriculture andConsumer Services, no mention of the Lake Okeechobee Watershed Project). This clear lackof knowledge and absence of consultation with the state partners brings into question theFWS’ understanding of the science. There are several unsubstantiated claims that need tobe addressed throughout the document.

9. Section 2.3.6, Interrelated and Interdependent Actions - While the BO acknowledges thateach alternative of LORS included the temporary forward pumps, this section insists that thereis no interrelated or interdependent action.

10. Section 2.4, Cumulative Effects - Suggest deleting all reference to the Department ofCommunity Affairs (DCA), since this agency no longer exists.

11. Section 2.4, Cumulative Effects, states that the way the Service ensures ongoing consultationwith the District is through its participation in the District’s Lake Okeechobee Committee of theWater Resources Advisory Committee (WRAC). The Lake Okeechobee Committee of theWRAC has not convened since January 2011.

12. Section 2.5, Conclusion - While the FWS cites the lack of appropriately timed water restrictioneffects on Snail Kites ABOVE Elevation 10.5 feet, there is no mention that the antecedentconditions leading to the need for the TFPs are not under District control. The FWS seeks towrest water supply authorities from the State and have detrimental effects to existing waterusers such as the Lower East Coast, Seminole Tribe, agriculture, City of Pompano, andothers. In addition, the TFPs also provide water to the STAs which are necessary to maintaintheir integrity for compliance with the Clean Water Act permits issued by the FloridaDepartment of Environmental Protection (FDEP).

13. Section 2.5, Conclusion - Per FWS communications, language describing the steps toaddress stakeholder concerns under a pending reinitiation process were supposed to beprovided by the FWS, no such description exists in this section or Section 5.0, ReinitiationNotice.

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14. Sections 2.6.3 and 2.6.4, Reasonable and Prudent Measures and Terms and Conditions.

a. The reasonable and prudent measures and the terms and conditions identified in the draftBO do not pass the test in 50 CFR 402.14(i)(2) including that the FWS cannot “alter thebasic design, location, scope duration or timing of the action” nor violate the “minor changerule”.

b. FWS believes that the following is necessary or appropriate to minimize take “… conditionthe DA permit for the operations of TFP such that the District will not operate any TFP untilthe Lake Okeechobee water level has dropped to or below 10.20 NGVD.” This wouldforce the District to wait or limit installation activities until 10.2 feet NGVD so that we canstill deliver water from those structures without the pumps in place. Worse yet, this wouldassert some new found authority for control of water supply to the USFWS.

c. Why are the operational restrictions only specific to TFP when the majority of the incidentaltake is attributed to LORS?

15. Section 2.6.5, Monitoring and Reporting – In addition to comments 2 and 3 above,

a. “The Corps will require the District to report the progress of the action and its impact onthe species to the service…” Note: it goes on to say that “… this will include snail kite neststhat may be active prior to installation of the TFP, but that fail after operation of TFPbegins…” The way FWS proposes to do this is via cameras. While the monitoring sectiondoesn’t explicitly say the District shall use cameras to monitor nests, Appendix Caddresses “Steps for Determining Snail Kite Nest Failure for Portable Forward PumpsBiological Opinion.” In that Appendix, it implies that the use of cameras is necessarybecause of TFP implications (both below and ABOVE 10.20). Who is responsible?

b. The District disagrees with the requirement to place cameras on 30 active nests for atleast five years and views this as an excessively costly burden to the taxpayers of theState of Florida. Based on a review of the equation described in Appendix C and theparameters included in the equation such as the duration of the nesting cycle, evaporationrates and volumes of water pumped at the TFPs, the FWS would have the ability tocalculate take with the use of field data gathered by other means and without the need forcameras.

c. If the opportunity to do in-lake habitat restoration presents itself, USFWS has included thefollowing… “The Corps will schedule a meeting between all Lake Okeechobeestakeholders and resource agency staff in early December if the mid November Lake levelis less than or equal to 13.0 ft.” It goes on to say that this will allow “the District to prepareand apply for any necessary FDEP and Corps permits for in-lake restoration activities.”This assumes that there may be some mechanism to force the District to use funds toimplement restoration activities.

16. Section 3.4, Cumulative Effects (Critical Habitat) - “General water quality conditions in snailkite critical habitat are likely stable or improving. The adoption of Total Maximum Daily Loadsfor phosphorus combined with Best Management Practices upstream of Lake Okeechobeeshould benefit water quality conditions in Lake Okeechobee’s critical habitat. Similarly, theestablishment of the phosphorus water quality standard in the Everglades Protection Areashould serve to improve water quality conditions in critical habitat in the WCAs and Everglades

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National Park; however, there is a current effort by the District to roll-back these protective standards (Miami Herald 2017).” The last statement has no place in what is supposed to be a technical document. It is a political statement made to further an agenda.

17. The Conservation Recommendations (Section 4.0) appear to be above and beyond the needsof the FWS to regulate and enforce the BO.

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ASB Review of 2017 Draft LORS PFP Biological Opinion

Overall Comments • The draft BO assumes on average, 94% of all nests and/or fledglings on Lake Okeechobee will perish

because of the combined effects of LORS/PFP and natural causes; essentially estimating a 63%

decline in production because of LORS/PFP. The explanation is that 31% of all nesting attempts on

the lake each year will fail from causes beyond the scope of the BO; 42% of nests above a certain

elevation (or 36% of all) will fail from high recession rates under the LORS, and fledglings from the

27% successful nests will perish from the recession rates under LORS and/or PFP (36%+31%+27% =

94%) (see Pie Chart at end of document).

o The 42% figure comes from estimating a difference in nest success rate between predicted

and observed rates. However, the BO assumes an unusually high “natural” nest success rate

of 69% would occur on Okeechobee if not for recession rates experienced under LORS/PFP,

and unusually low observed nest success rate while LORS has been implemented. The

observed rate was calculated by averaging annual rates (average of averages) instead of

dividing total successes by total attempts over the entire period. The method used in the BO

gives equal weight to years with 15 nests to those with over 200 nests. For example, if kites

attempt 1 nest in a given year and it fails, that’s a 0% success rate. If the next year they

attempt 100 and 50 succeed, that’s a 50% success rate. Given the number of attempts, the

second year would clearly provide a more representative estimate of success for the system.

But if you calculate the average rate over the two years by averaging the annual rate it

would be 25% ((0%+50%)/2) vs 49.5% ((0+50)/101) if you summed the successes and divided

by the attempts. The method used in the BO would estimate it at 25%.

o The result of using an unusually high predicted success rate and miscalculating the observed

success rate is an overestimate of the difference between predicted and observed, and an

overestimate of take. Further, the difference itself, however it’s calculated, cannot be

attributed solely to the effects of LORS and/or PFPs. Kite nest success varies from year to

year and by location, and is affected by temperatures, water levels, food availability,

predator type and abundance and access, and rates of water level ascensions and

recessions, and others (disease, toxins, age).

• The BO recognizes the positive effects LORS has had on kite habitat, extreme stages, and water level

recession rates (relative to WSE), yet still assumes Lake Okeechobee under the LORS is a snail kite

population sink; attracting kites to nest in record numbers, but causing 63% of all nests and

fledglings to perish (above and beyond the 31% failures from natural causes). There is not sufficient

evidence provided in the BO, other than frequency of potentially harmful recession rates, to

substantiate the claim that LORS has had such a detrimental impact to nesting productivity on the

Lake, especially given the record high nesting activity that occurred just last year, and the rebound in

nesting in general on the lake since 2010.

• The condition that PFPs not be operated until 10.2 ft appears to undermine the take analyses, in

that they were all estimated based on past use, or use at 10.6 ft. The take calculations for nests

during PFP operation used 10.6 ft, rounded down to 10.5 ft, to estimate effects. This condition

would seemingly warrant additional analyses of take for future operations.

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• Despite massive declines in nesting and foraging activity in WCA3A during IOP, the ERTP BO does not

attempt any of the same take calculations performed in this Lake O document, where nesting

activity has increased over time. In fact, despite admitted improvements to Lake habitat under

LORS, this BO appears to suggest LORS is more detrimental to snail kites than IOP or ERTP, in that up

to 33 nests and 19 fledglings are estimated to be lost every year… which far exceeds the average

production from WCA3A in the last 20 years.

The ERTP BO made no attempt to calculate nest losses based on a difference in observed and

predicted success rates in WCA3A (as was done here), or to calculate numbers of fledglings harmed;

and no terms and conditions to help answer pertinent questions about things like where juveniles

migrate to from WCA3A under different hydrological conditions (GPS tags on kites), or why nests fail

each year and whether it’s attributable to water management (nest camera studies). Given the well-

recognized historical importance of WCA3A and its current, dismal state; and Okeechobee’s

apparent revival and record-setting production in the recent past; why does this BO estimate such

high levels of take and lengthy terms and conditions in comparison?

Specific Comments P 14, L 1880 – Speculation, author is not taking into account natural outflows, groundwater losses, etc

that could have led to higher recession rates than cited here.

P 17, L 631 – Author references old citation, which is no longer supported by more recent analyses…

including the Figure cited to support the sentence. Specifically, adult survival did not appreciably dip

between 2006 and 2008, and certainly not by 35% as suggested in Cattau et al. 2009. Later analyses

suggest it was only a small drop (5%?), but that it persists to this day (no recovery). This may be of

importance because the earlier citation overestimated the effect of a drought on adult survival, and was

too early to detect the persistent lower survival afterwards, i.e. it overestimated the recovery as well.

P 29, L 1152 – Dr Wilde also confirmed Lake Istokpoga has Hydrilla with Aetokthonos hydrillicola (the

algae linked to AVM), and that they have looked for but not found it in Okeechobee. She suggested the

different geological basin (lake sediment types) of Okeechobee may prevent it from growing there.

P 29, L 1175 – Author suggests water depths between 4 and 20 inches during the snail breeding season

are ideal but that is based on Darby’s work in the Everglades, which may not be comparable to lake

systems (see recent FWC presentation on East Lake Toho snail monitoring – Jen Bernatis).

P 30, L 1193 – Author states juvenile survival is trending down since 2010, but doesn’t mention numbers

of juveniles produced has been trending up; which may mean numbers entering the population are

stable. No survival data yet for 2015 and 2016 fledglings, which were more abundant than ever, but if

survival stays low it may also suggest a statewide carrying capacity has been reached.

P 37, L 1388 – Author appears to be referencing 2011 SAV data to estimate a generous amount of SAV at

low elevations. Recall that 2011 followed a year after severe droughts (07,08, 09 all got to 10.5 ft or

lower) so it’s likely that the elevations SAV occupied that year were much lower than under normal

conditions. The likelihood of another drought occurring like 2011 with similar antecedent conditions is

exceptionally low, and most likely there would be even less available habitat than is estimated by the

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author, or rather there would be fewer kites using the lake by the time PFPs were installed than in 2011.

For example, no nesting was observed in 2001, 2007, 2008, or 2009 when PFPs were operated.

P 47, L 1804 – Author again references Darby’s work from the Everglades to suggest optimal water

depths for snail reproduction. No such data have been collected for lake systems and may or may not be

relevant to outer littoral marshes in Okeechobee. However, it may be relevant for the interior marshes.

P 49, L 1917 – As the author states, the recession rate calculations done by the USACE doesn’t account

for any changes in lake stage between the nest start and end dates, other than the start and end stage

and assuming a linear recession between the two. However, as Fletcher et al. (2014) pointed out in their

recession and ascension analysis, “Daily nest survival rate consistently declined with increasing

ascension rates across wetlands” as well. Considering the Corps failed to account for ascension events in

their analyses, and Fletcher et al. did such a thorough statistical review of a much larger dataset, it

seems the 0.26 ft/wk used by Fletcher would be more accurate as a threshold at which daily nest

survival declines, than the 0.19 ft/wk proposed by the USACE.

P 52, L 2017 – Inappropriate, author is purely speculating about District’s water supply operations and

decision-making.

P 52, L 2020 – Incorrect, author is not aware of gravity flow constraints at various structures when lake

stage is at 10.2 ft.

P 52, L 2051 – Inappropriate, author is purely speculating about District’s water supply operations and

decision-making.

P 57, L 2280 – Incorrect, FDEP has lead on water quality issues through BMAPs.

P 65, L 2625 – This statement shows that PFP use in 2011 did not affect kite nesting, nor has it in any

prior use.

P 66, L 2647 – Table 2. Author apparently is calculating average annual success rate by averaging the

rates from each year, rather than tallying all successful attempts over the period divided by all nest

attempts over the period. The former gives the same weight to a year in which only 15 attempts were

made (2010) vs 221 (2016). The latter approach, and arguably the more biologically meaningful, would

be to use all successful nests (P 96, Table 11) divided by all attempts, or 218/570=38%. This success rate

is much higher than the 29% used by the authors, or the 27% used for the “spring” attempts. The

authors are underestimating the breeding success in the lake and are thereby overestimating estimates

of take attributed to LORS.

P 80, L 2782 – Incorrect, water could still be leaving the lake to estuaries, going through G207, G208 to

other water users, etc.

P 81, L 2854 – Author cites the Corps BA (2016) that WSE performed worse at low stages than LORS.

SFWMD commented on said BA that climate varied dramatically between the periods of record

comparing WSE to LORS, and that the appropriate analyses should have been on modeled results, not

observed data. Authors do state a few sentences later that climatic variability will likely alter the pattern

of fewer low water conditions under WSE than the limited period of LORS to date.

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P 82, L 2896 – Author states they do not accept District’s estimates of PFP withdrawals, which account

for water that would have been discharged by gravity if pumps were not installed. FWS uses total

amount of water pumped, rather than the estimated effect of pump operation vs no pumps. The District

has continually stated this represents an overestimate of pumping effect because it neglects what would

have been discharged if the pumps were not in place.

P 91, L 3247 – Author states a 69% success rate for kite nests is closer to their “natural” rate on

Okeechobee. This would be highly unusual, is unsupported in the literature for anywhere in the state,

and is based on an extreme event on the Lake in 2016. Fletcher et al. (2015), which is repeatedly

referenced throughout the BO, shows nest success statewide from 1994-2015, and only twice was it

ever calculated above 60% (Figure 10b, p77, Fletcher et al. 2015, shown below).

The authors appear to have purposefully selected other unusual, isolated events in wetlands where

success rates were also over 60%. All of the wetlands cited are either created wetlands (STAs, Mary A

Mitigation Bank), or marsh habitats (WCA3A and Hungryland Slough); not lacustrine, and they also

experience years of low nest success and productivity. Why the chosen years and locations are

representative of “natural” success rates, or why they were used as justification for a 69% rate on

Okeechobee is unclear. Suggest using a rangewide, long-term average or something similar (see below).

The annual summary tables from each of the Snail Kite Monitoring study reports from 2002-2015 show

the state-wide success rate for each year varied from 19-50%. If you divide the total number of

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successful nests over that 14 year period by the total number of attempts, you get an average of 37%

rangewide. This estimate is a little low because earlier reports didn’t always differentiate between a

nest that reached egg laying stage and those that didn’t, so the total number of attempts may have

been inflated in some years (higher denominator). But the 37% rate is close to the mean estimate of

41% calculated by Dreitz et al (2001) that reviewed kite nesting data from a variety of studies spanning

22 years. Regardless, literature shows kite nest success is highly variable from year to year (Snyder et al.

1989), making it hard to estimate a “natural” rate representing normal water, food, and predator

conditions.

A comment above that references Table 2 also shows how 27% is a substantial underestimate of nest

success during the LORS period of record because it gives equal weight to every year, regardless of

whether there were 15 nests or over 200.

Further, the authors appear to suggest the 69% success rate seen on Okeechobee during an extremely

rare breeding event in late 2016 was a result of flat or rising water levels; and from there suggest

anything lower than 69% is likely a result of steep recession rates because of LORS. However, the event

in 2016 was a result of plant management that opened thousands of acres of foraging habitat that was

dense cattail prior, and a year or so later was apparently filled with high densities of snails and made

unusually good foraging and nesting conditions for kites. In fact very rarely before have as many nests

been recorded on the whole of Lake Okeechobee, as occurred in these 2 treatment plots in 2016. They

also primarily occurred after the traditional nesting season was winding down (June to November). Why

the authors chose this out of season, high density nesting event that took place in a herbicided and

burned treatment area filled with exotic snails was indicative of a “natural” success rate on the Lake is

unclear.

It is unclear what the authors are using as a comparison to estimate the LORS impacts to nesting kites.

Authors acknowledge LORS is an improvement over WSE in terms of habitat, recession rates, and

extreme stages (with the exception of potentially more frequent extreme lows), but assume LORS is

severely impacting nests and fledglings (63% losses) because of high recession rates. It appears they are

basing this on differences between recession rates that occurred historically (1931-2000) and since LORS

was implemented (2008). Table 6 summarizes their hydrological comparisons of recession rates, while

Table 7 shows extreme stages. Table 6 shows that despite fewer occurrences of recession rates above

the threshold Fletcher et al. calculated would reduce daily nest survival (0.26 ft/wk), they assume

massive losses of nesting under LORS. This is apparently due to a greater frequency of occurrence of

recession rates between 0.127 ft/wk and 0.25 ft/wk, which was not identified by Fletcher as having

negative effects. It appears the authors are using the USACE BA, which cites a rate of 0.19 ft/wk as a

threshold. However, that was calculated by simply subtracting lake stages at the end of the nest attempt

from the stages at the beginning, and didn’t take into account ascensions, or reversals that may have

occurred in between. Fletcher et al. used 7-day recession rates and conducted thorough statistical

analyses to reach their conclusion, but the authors use the USACE rate throughout.

Further, when the average 7-day recession rates (ft/wk, calculated without ascension events) are

plotted for each of the 3 periods, the differences between historical rates and those under LORS do not

appear to justify such negative assumptions about nesting conditions under the LORS. Recession rates

under WSE, however, do appear to have been higher on average, during May especially, than the other

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periods. It should be noted that these 3 periods have vastly different extents, with the historical POR

covering 69 years and the others only 8-9 years.

P 91, L 3260 – Authors attempt to estimate take of nests for LORS by using the estimated difference

between a “natural” success rate of 69% and their calculated “observed” rate of 27% during the spring

(Jan-Jun) of all LORS years. They suggest LORS is responsible for a loss of 42% of all nests on the Lake

each year, but fail to account for how many nests LORS may be responsible for each year as a result of

improved habitat, slower recession rates, and more stable hydrology than WSE. Using 42% as their loss

rate, they apply that to the mean annual number of nests above 10.5 ft elevation (67.6) and estimate 29

nests a year will fail as a direct result of LORS, which they attribute to high recession rates. However,

they later estimate that fledglings from the 27% successful nests will also be taken as a result of LORS

and PFP combined. So essentially, the authors overestimate the LORS impacts by using an unusually high

“natural” success rate, and then assume any fledglings that do get produced will perish because of LORS

and/or PFP. See the Pie Chart at the end of the document for an explanation of how the authors

estimate a take of 63% of nests and fledglings for LORS and PFP.

P 91, L3264 – Authors state they are only applying the take to nests during the spring, but use the mean

number of nests from Table 11 (all season), instead of Table 10 (Jan-Jun 30).

P 91, L 3267 - How will the take of 29 nests that is attributed to LORS be calculated to determine

whether or not there’s an exceedance? Only calculations for PFP take is described in the appendix.

P 93, L 3357 –Author is calculating how many fledglings are put at risk by LORS and PFP each year, even

though take of nests was already calculated at 33. The combined effects of the nest and fledgling take is

63% of all nesting activity every year. However, the BO stated earlier in the document and in Table 7

that LORS has improved snail kite habitat, reduced high water impacts, reduced low water impacts, and

improved recession rates from those experienced under WSE. So what is LORS being compared to?

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“Historical” lake stages that occurred between 1931 and 2000? Were the effects of ERTP calculated as

such?

P. 93, L 3331 – Authors admit here that 69% was a maximum success rate, so it should hardly be used as

a baseline. Further, they use this estimate to calculate take from PFP use, which will only occur during

very dry years, when nest success tends to be lower already because of limited habitat. It’s one thing to

use a high estimate of nest success to attempt to calculate effects of a LORS recession rate, but to use it

to calculate losses of nests from PFP use during droughts is not appropriate. If anything, a much lower

estimate should be used than even a 40% rate, which would further reduce the estimate of nests taken

from PFP use.

P 95, L 3412. Table 9 shows the District’s calculations of actual volumes pumped after you subtract what

would have been lost to gravity discharge if the pumps hadn’t been installed. It shows that in 2007,

which was the year in which the pumped volume had the highest ratio to ET losses, the percent drop in

lake stage attributable to pumping was 3.5”/(3.5+14.7”) = 19.2%. This is quite different than the “worst

case scenario” estimate of 33.7% losses to pumps estimated by the authors. Combined with a more

realistic nest success estimate of 40%, which would be quite conservative during a drought year, it

would change the amount of nests calculated for take to 13.9*0.4*0.192= 1.07, or rounded down to 1

per year. This is a difference of 3 nests per year from what the authors calculate as a conservative

estimate of take.

P 96, Tables 10 and 11. The 2011, 2012 and 2013 nest data is substantially different from what was

reported in the annual demographic reports. According to the annual reports, there were only 39, 76

and 86 active nests on Okeechobee, respectively, and only 35, 73 and 77 of which had a known fate.

According to the official reports the total failed was only 19, 50 and 48, respectively, which made a

season-long nest success of 44%, 32% and 38%. Much higher than the 23%, 17% and 26% reported in

Table 2. This would change the estimate of take for nests, by bringing the total success rate calculated

by FWS under LORS to well above 27%, and change the mean number of nests per year as well. If the

nests were below 10.5 ft, it will also change the amount estimated for PFP take.

According to FWS, the UF snail kite researchers have gone back and edited data from 2011-2013 and

changed totals, but they are substantially different from what was reported earlier (e.g. 31 more failed

nests in 2013). Some clarification should be added to the BO or the numbers verified to avoid confusion.

See the Table below for an example of how substantial these differences are and how they could affect

take estimates.

Further, Table 10 shows 56 known fate nests from Jan-Jun 30 in 2014, while Table 11 only shows a total

of 50 known fate nests all year for 2014. I assume Table 10 may be showing an incorrect total for 2014,

though it doesn’t appear the numbers were used for any analysis.

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Discrepancies between the BO and Annual Report Nests

DraftBO

Annual Reports

Year Successful Failed SuccessRate

FailedSuccess

Rate

2010 1 14 6.7% 12 14%

2011 7 23 23.3% 19 44%

2012 15 76 16.5% 40 32%

2013 28 79 26.2% 48 38%

2014 26 24 44.1% 25 50%

2015 18 38 32.1% 38 32%

2016 123 98 54% 98* 54%*

Avg Annual 29% 37.7%

Total Avg 218 352 38.2%* 280 43.8%

Avg Annual Total Nests

81.4 71.1

*Annual report not released as of this writing

Potential new take calculation for LORS, if you still assume an unusually high predicted success rate of

69%. 69% - 44% = 25% reduction in nest success X New Mean annual # of nests (71.1) = 18 nests.

Of course, 44% is not a poor success rate on average and one could argue that based on these numbers,

there actually isn’t any difference between a predicted and observed success rate (no take of nests). But

if you apply the higher success rate to the new annual mean you’d have a higher estimate of fledgling

take (26 per year vs 18). Of course it’d be hard to justify such a high fledgling mortality if there’s no

estimate of nest take.

P 110, L 3790 – All of the incidental take calculations and rationale were based on past pump usage, and

the BO cites 10.6 ft as the basis for its evaluation of take throughout. This permit restriction of not

operating pumps until 10.2 ft appears to have the effect of reducing the estimates of take likely to

occur. For example, the elevation of 10.5’ was used to estimate how many nests would be impacted by

PFP use, which is obviously an overestimate if PFPs can’t be used until 10.2. Similarly, more take might

be assigned to LORS if the “switch” between the two impacts is actually being restricted to a lower

stage. Why did the authors analyze how many nests occurred above and below 10.5 ft in elevation if

they are limiting future PFP impacts to stages below 10.2 ft? It may also not be logistically feasible to

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install the pumps and then not operate them until a lower stage, given that they obstruct flow to some

degree.

P 111, L 3869 – While nest cameras will be able to show whether and how a nest was predated or

otherwise failed, they still cannot determine whether a given event would have occurred under different

scenarios. Barring widespread abandonment of eggs or young, which would clearly be evidence of a

sudden loss of foraging habitat, predation by a raccoon or snake will not clarify whether PFPs or LORS

was responsible. For example, raccoons may be more prevalent in the vast littoral marshes of

Okeechobee than they were on Lake Toho, where the only other camera study was conducted. Or they

may be completely absent because of the perimeter canal. And they may be able to access nests in a

bigger variety of water depths on Okeechobee than on Toho, as well. And while ratsnakes were found

closer to shore on Lake Toho, they are likely ubiquitous in the dense littoral zone of Okeechobee.

Basically, until enough years of nest camera monitoring are conducted under enough of a variety of

conditions, not much can be said about the results since they may not be comparable to other areas. Is

the information gleaned really worth the cost and potential increased disturbance to the nesting kites?

Further, if this camera study is to be used to estimate take from LORS/PFP after the fact, they would

have to be randomly placed on nests or cover a variety of nesting areas and times throughout the

season in order to have inference about the unmonitored nests.

P 112, L 3878 – Camera checks once per week will increase disturbance at the nest and may inflate

failure statistics.

P 120, L 4185 – Newspaper articles are generally not respected as a source of scientific information.

Graphic depicting how many nests and/or fledglings are estimated to be harmed (taken) in the draft BO.

DRAFT

10

The BO estimates 81.4 nests/yr, 67.6 of which are above 10.5 ft elevation and attributed to LORS

impacts. A success rate of 69% is assumed to be natural on Okeechobee (31% of nests expected to fail

from natural causes beyond scope of BO). An observed success rate of 27% (22 nests) was calculated

under LORS period of record, yet any fledglings from those nests were assumed to die (50% from natural

causes, 50% from LORS/PFP recession rates). Therefore, 6% of all nest attempts were expected to

fledge young on an annual basis, according to the BO; or a 63% loss (36+27) over what would have

occurred if LORS wasn’t in effect. But under what conditions?

Literature Cited

Dreitz, VJ, RE Bennetts, B Toland, WM Kitchens, and MW Collopy. 2001. Spatial and temporal variability

in nest success of snail kites in Florida: a meta-analysis. Condor 103:502-509.

Fletcher et al. 2014-2015, etc. – Annual demography reports cited by USFWS draft BO.

Snyder, NRR, SR Bessinger, and R Chandler. 1989. Reproduction and demography of the Florida

Everglade (Snail) Kite. Condor 91:300-316.

25 Nests31%

22 Nests27%

29 Nests36%

5 Nests6%

81 NESTS PER YEAR

Natural Failures LORS/PFP Fledgling Mortality

LORS/PFP Failures Successful Nests

DRAFT

1

Review of March 21, 2017 Draft USFWS Biological Opinion (BO)

Lake Okeechobee Regulation Schedule and Portable Forward Pumps

Date: April 5, 2017

BO Conclusion:

The March 21, 2017 draft BO concludes “the proposed actions, 2008 Lake Okeechobee Regulation

Schedule (LORS) and Portable Forward Pumps (PFPs), are not likely to jeopardize the continued

existence of the snail kite or result in destruction or adverse modification of its designated critical

habitat. The BO includes an Incidental Take Statement exempting anticipated take from the prohibitions

of the Endangered Species Act provided such taking is in compliance with its terms and conditions.”

General Comments:

This review is limited to the portions of the March 21, 2017 U.S. Fish and Wildlife Service (USFWS) draft

Biological Opinion (BO) that attempted to provide quantitative hydrologic effects of the PFPs during the

times they were used. This reviewer’s expertise includes hydrology and water management in south

Florida, but does not include biology. So the ecologic portions of the BO are not within the scope of this

review.

The fundamental flaw with the hydrologic analysis documented in the January, 2015, draft BO, and the

July, 2015 draft BO, was not corrected and remains in the March 21, 2017, BO. Therefore, the central

hydrologic question the USFWS attempted to answer is inappropriate.

The hydrologic question implicitly addressed in the BO was:

How much lower do Lake Okeechobee stages fall during PFP events, assuming no Lake releases would be

made if the PFP’s were not installed?

The appropriate question that should have been addressed is:

How much lower do Lake Okeechobee stages fall during PFP events, assuming typical operation of the

gravity spillways would occur if the PFP’s were not installed?

The US Army Corps of Engineers (USACE) and the USFWS requested and were provided information

from the SFWMD to answer the appropriate question (SFWMD 19-Oct-2011 & 28-Jan-2014). However,

the BO explicitly “did not accept” use of this information. Consequently, the BO’s analysis makes the

inherent assumption that if the PFP’s were not installed, then no water supply releases would be made

to the Everglades Agricultural Area (EAA), Stormwater Treatment Areas (STAs), Seminole Tribe of Florida

(STOF) Big Cypress Reservation, Everglades WCAs, or the Lower East Coast Service Areas. This inherent

assumption is unrealistic and over-estimates the effects of the PFPs on Lake Okeechobee stages by up to

250%. All subsequent biological analyses in the BO that are based on the results of the inflated

estimates of the hydrologic effects of the PFPs are therefore flawed and dramatically over-state the true

effects of the use of the PFPs versus the traditional use of the gated spillways, S-351, S-352, and S-354.

DRAFT

2

Specific Comments:

P7&P2, DESCRIPTION OF PROPOSED ACTION: “For this BO the “action” is comprised of two

components – LORS and PFP… Therefore, we will retain the use of “LORS” and “PFP” when indicating

separate effects of the action, but the term “action” when considering the entire suite of effects.”(p7)

“This project also consists of temporary installation and operation of PFP at three locations on Lake

Okeechobee to deliver water south of the lake during low-water conditions when the existing water

control structure flow capacity would otherwise be diminished.”(p2)

Comment: The statement: “ … to deliver water south of the lake during low water conditions when the

existing water control structure capacity would otherwise be diminished” is accurate in the sense that

diminished means decreased, lessened, declined, or reduced. However the USFWS analyses in the BO

assumes the existing gated spillway structure capacity would be zero if the pumps were not installed.

The SFWMD’s 19-October-2011 analysis estimated the potential spillway capacity during the historical

drought events when the PFP’s were installed. The gravity flow capability was not zero, rather the

capacity was likely even greater than the conservative estimates that were provided by the SFWMD.

Neglecting the potential gravity flow (without pumps) results in over-estimating the effects of the

pumps as described in the general comments above.

Sec 2.3.3, p82, states: “The Service does not accept this subtraction of gravity-flow water blocked by

PFP in our analysis of PFP effects on species. The federal action being assessed in this biological opinion

is Corps’ proposed reissuance of a permit for the temporary installation and operation of PFP at the

south end of Lake Okeechobee and its effects on the Snail Kite, which necessarily involves an evaluation

of the actual amount of water removed from Lake Okeechobee by PFP. Evaluating a lesser amount

based on gravity flow that did not occur would be too variable and could not be used for accurate future

predictions of PFP use if lake stage is unknown.”

Comments: The USFWS decision to ignore gravity flow potential is erroneous and is basically assuming a

baseline of no water supply releases. Their assumption significantly overstates the relative effects of the

proposed action (pumping) versus the alternative of no-action (gravity flow).

The following table compares the magnitude of the erroneous over-estimation. The correct estimates

were provided to the USFWS and USACE in 2011 per their request.

USFWS-calculated effect Correct estimate per Table 2 of 19-Oct-2011 % erroneous

Year of PFP on lake stage SFWMD analysis, provided to the USFWS over-estimation

2001 3.61” 1.02” (=25.9 kaf/ 304.3 kac *12) 254%

2007 4.90” 3.55” 38%

2008 5.04” 2.09” 141%

2009 0.10” 0.06” 67%

2011 1.58” 0.51” 210%

DRAFT

3

For example, by not considering the fact that the gravity spillways could deliver at least an inch of water

supply during the 2011 event, the USFWS estimate of the reduction in 2011 Lake stage due to pumping

was over-estimated by a factor of 3.1 (=1.58”/0.51”). In other words, the USFWS over-estimated the net

effect of pumping on Lake Okeechobee stage by more than 200%.

P50, para2 states: “The Corps (2016) analyzed recession rates over the entire year between WSE and

the LORS and concluded that the LORS has a higher percentage of recession rates faster than 0.127

ft/wk, but a lower percentage of recession rates exceeding 0.25 ft/wk (Table 6).”

Comment: This citation appears to be from the USACE 2016 Biological Assessment (BA), which

compared relatively short hydrologic periods that different Lake Okeechobee regulation schedules were

in effect. The comparison was for the LORS period vs the WSE period. The regulation schedule was not

the only variable during these periods. The historical data are helpful for identifying nesting success

relative to stage and stage recession rates (although there surely are factors other than water

management that affect nesting success). It is not clear why such a recession analysis was not

performed comparing the simulated stages from the LORS vs WSE from the 2007 LORS SEIS. That

analysis would discern differences due strictly to water management. Of crucial importance is the fact

that such an analysis of historical data does not separate the effects due to differing rainfall and inflows

for the 2000-2008 & 2008-2015 periods.

Section 2.2.2.4 Hydrologic Management Effects on Snail Kites This section defined hydrologic

management to include water releases for flood protection, holding water in lakes for water supply, the

timing of water restrictions, and releasing water for water supply or for environmental benefits such as

releases from Lake Okeechobee to the Caloosahatchee Estuary during the dry season. The following

excerpts (pp 50-51) are noteworthy: “In 4 of the 5 years that PFP were used, snail kites did not attempt

to nest in Lake Okeechobee prior to pump installation. However, in 2011, water levels were high

enough that snail kites initiated nesting in February.” Figure 20 shows nest failures occurred before the

PFPs started pumping on May 31st.

Comments: This section also contains much conjecture on how modifying water restrictions would

presumably help snail kites and snail kite habitat (pp 51-52). Several very rough calculations are

described, which make simplifying assumptions about water use and effects of modified water

restrictions. The resulting over-estimated difference in Lake Okeechobee stages are not evaluated with

regard to how snail kites or habitat would be effected. Again, this is speculation that the PFPs have

meaningful effect on stages and recession rates. No sound technical basis is given to support this

conjecture. Only questioning of the water management actions is provided, with no specific evaluation

of hydro effects on Kites.

The BO asserts that PFP’s allow delayed initiation of cutbacks, and more severe cutbacks earlier could

have slowed recession rates. Starting at the bottom of page 51 the BO speculates that “water managers

may view the ‘guarantee’ of up to 1400 cfs of water potentially provided by the PFP as a reason to not

declare water restrictions earlier in the season.” This reviewers understanding is that no such logic was

DRAFT

4

used by water managers to decide the timing of water restriction phases during the 2011 drought, or

any of the other five PFP events. The USFWS speculation appears neither accurate nor appropriate.

Page 52 provides over-simplified and erroneous calculations to estimate how much higher the 2011 lake

stages would have been if higher water use cutbacks had been implemented prior to use of the PFP.

Their basic calculation assumed the one foot drop in lake stage during 3/26/2011 to 5/19/2011 was

partly due to evaporation and the remainder due to water supply releases. Their calculation assumed

an unrealistically-low value of evaporation (5.28”) during the 55-day period, which is about half of what

the actual data shows (10.7” per SFWMD DBHYDRO DBKEY OH519). The FWS estimate of water use was

6.72” (12”-5.28”). The water use estimate using the actual evaporation data is 1.3” (12”-10.7”).

Thus the FWS dramatically over-estimated the benefits from implementing higher cutbacks earlier. For

example, assuming Phase 3 (45%) water-use cutbacks had been implemented on 3/26, the FWS

estimates the lake stage would have been 2” higher on 5/19. Using the above more-realistic estimate of

evaporation, the same rough calculation indicates the stage would have been only 0.4” higher on 5/19,

prior to use of the TFP. Regardless of the estimated hydrologic effect, the BO contains no ecological

analysis to support the assertion that earlier declaration of Phase 3 water use restrictions would have

prevented nest failure. Furthermore, this section of the BO has nothing to do with LORS or PFPs.

Section 2.3 EFFECTS OF THE ACTION: “This section addresses the direct and indirect effects of the

continued operation of the LORS and the installation and operation of PFP on snail kites, including the

new snail kite science related to recession rates. This section also addresses the effects of interrelated

and interdependent actions. Direct effects are caused by the action and occur at the same time and

place. Indirect effects are caused by the action, but are later in time and reasonably certain to occur.”

Section 2.3.1 states “When PFP are in operation, we anticipate that lake levels are receding due to PFP

and evaporation and not due to other LORS operations (the assumption is that water supply is leaving

the lake via PFP operation only).”

Comments: The BO fails to state that the LORS does have an indirect affect on PFP. LORS is a lower

regulation schedule and decreases the frequency and duration of both high and low stages, thus causing

increased need to install and use the PFPs. The USACE’s 2007 LORS SEIS demonstrated this.

Section 2.3.3 Past Use of PFP: Comments on this section were moved up to the top of this review.

Section 2.3.4 Analyses for Effects of the Action (pp83-84): This section states “The basis of our

determination that the proposed action may adversely affect the snail kite is three-fold: a[1]) past lake

level recession rates have been high enough in some years to cause, either in part or entirely, the failure

of snail kite nests; 2) the increased probability that the littoral zone and nearshore zone will dry more

frequently and for longer duration with PFP than without PFP; and 3) snail kite fledglings less than four

months old are at increased risk of mortality due to both high recession rates and additional lake

bottom drying resulting in lower apple snail availability due to PFP operation.”

Comments: The data analyses in the BO does not demonstrate the PFP’s have produced recession rates

that have caused failure of snail kite nests. Thus the first and second items in the list are independent,

DRAFT

5

based on the history. The implied dependence appears hypothetical. Thus the causal impacts of the

PFPs has not been demonstrated, and the basis for the determination that the PFP component of the

proposed action may adversely affect the snail kite appears to be based on potential future events that

have not occurred in the past.

P84: Also contained in this section is a discussion of the SFWMD’s MFL Rule for Lake O. The Service

expresses concerns “that there may be a concomitant increase in future violations of the established

MFL for Lake Okeechobee.” And they go on to suggest a change to the frequency component of the

MFL to better protect snail kite habitat.

Comment: The BO should acknowledge that the USACE’s SEIS for LORS identified an increase in low Lake

Okeechobee stages and potential increases in MFL rule exceedances. Analysis done by the SFWMD in

2009-10 to develop the Adaptive Protocols for Lake Okeechobee Operations further quantified the

effect of LORS on the Lake O MFL Rule.

P85, 2nd full para: Comment: Text blames the high recession rates in 2011 for 13 or 14 failed nests; but

PFPs were not operating during the time of high recession rates. Subsequent text cites past PFP

initiation stages as justification to ‘blame’ PFPs for failed nests. This appears illogical.

Section 2.3.4.2 Potential Loss of Foraging Habitat for Snail Kites and their Prey from PFP (pp86-88),

and Tables 14 & 15 (p98):

Comment: All statistics presented by the FWS in these tables and related discussions are inherently

flawed by their erroneous assumption that there would be no water releases by gravity if the pumps

were not installed. Estimated ecological impacts in the BO that are based on the flawed hydrologic

analysis are also over-estimated.

Also in this section on page 88, 1st para, last 2 sentences: “In 2011, even though the overall water drop

was not as great, the lake dropped to 10.5 ft on May 18, 2011 (when snail kites were nesting). So from

that perspective, the effect of PFP in 2011 was worse for snail kite reproduction in Lake Okeechobee

than in 2007 or 2008.”

Comment: The PFP’s were not used in 2011 until May 31st. So the ‘water drop’ was not due to the PFPs.

P87, 2nd para: Comment: This discussion accounts for the lake evaporation during the PFP events, but

makes an over-simplified calculation to estimate the contribution from the PFPs. For example, in 2007

the table shows a total of 29,210 acres dewatered by PFP and evaporation, a 19.60” stage reduction

during the 78-day period (3/28 – 6/13). The effects from the PFP are estimated by a simple proportion

of the raw pump amount (unadjusted) to total stage reduction (4.9”/19.6” = 25%). The stated acres

dewatered by PFP (7,303 acres) was estimated by multiplying the 25% times the 29,210 acres noted

above.

This over-simplified calculation is misleading. Pumping during the event was not necessarily continuous.

The reduction in stage accumulates over time and does not necessarily have a uniform impact

throughout the duration of the event. A more useful analysis would consider and evaluate the effects of

DRAFT

6

the gradual reduction in lake stage through time to determine the timing of the reduced critical habitat

area. The analysis could be done for both the proposed action (with pumps) and no-action (existing

gravity spillway use). This would answer the relevant question ‘how much additional lake bottom is

exposed in meaningful habitat area due to pumping versus gravity flow?’ The BO contains no such

analysis and instead chose to create over-simplified and inflated estimates.

Section 2.3.8 Species Response to the Proposed Action:

Page 92, third full para: “We have also shown that past PFP use in 2007 dewatered up to 28,610 acres

of littoral and nearshore habitats and put at risk an estimated 122,000 to 582,600 native apple snails

from desiccation-based mortality.”

Comment: This statement gives sole credit to the 2007 PFP use for the entire Lake Okeechobee surface

area reduction of 28,610 acres. Evaporation is the primary reason for the stage and area reduction

during this period. The BO unfairly blames the PFP operation for the entire ‘dewatering’.

Page 93 contains verbage and calculations to “… predict a likely, worst-case direct effects analysis

resulting from PFP operation.”

Comments: This analysis and its rationale are convoluted and use various assumptions that result in

over-estimation of the “number of snail kite nests expected to fail due to the direct effects of PFP”. The

outcome of the calculation in the BO is: “Therefore, we predict PFP has the capacity to directly affect 4

nests”. This section does not appear to describe the basis for the statement in the Conclusion section of

the BO (p106): “We expect up to 29 snail kite nests would be directly affected by the action annually

under LORS operations.”

Furthermore the calculation was used to define “the maximum level of anticipated take” (p108, 2nd

para). “…even if the maximum level of anticipated incidental take occurs, it is the Service’s BO that the

continued operation of the LORS and the installation and operation of PFP, as currently proposed, is not

likely to jeopardize the continued existence of the snail kite. If more than 33 snail kite nests are taken

within one calendar year, the Service would consider reinitiation of consultation.” And according to the

last sentence in the BO on page 122: “In instances where the amount or extent of incidental take is

exceeded, the Service will determine if any operations causing such take must cease pending reinitiation

of consultation.”

Not only is the calculation methodology suspect, but its use as a “maximum level of anticipated take” is

counterintuitive. This reviewer’s opinion is that the PFP’s have much less of an impact on snail kites

than the BO estimates. If the assumptions made for the calculation of impacted nests are revised to be

less extreme, then fewer impacted nests will be estimated. However this would correspondingly reduce

the level of anticipated take. And if the maximum level of anticipated take is reduced, say from 33 nests

to something like 10 nests (for example), then exceedance of 10 failed nests will trigger action including

reinitiation of consultation and potential cessation of PFP operation. This is highly counterintuitive

because over-estimating the adverse effects on snail kites leads to a higher “take”, which appears less

protective of the snail kite because a higher “take” is less restrictive on the action. Another hypothetical

DRAFT

7

example is for an action that has absolutely no effect on an endangered species (ES), but by the

prejudice of the BO writers, they estimate a take number of 1 nest. If more than one nest fails, then the

action, which in reality has no effect on the ES, is subject to conditions and penalties. This makes no

sense. The less effect an action has on an ES, the less the penalty should be. Similarly, the more an

action has an effect on an ES, the higher the penalty should be.

This reviewer maintains there is relatively little effect of the PFPs on Lake Okeechobee stages and

recession rates while snail kites are nesting, especially compared to the effects from the 2008 LORS and

evaporation (see attached SFWMD analyses, which provides estimates of both PFPs and LORS on Lake O

stages). Considering the BO’s counterintuitive calculations and the uncertainty and bias in many of the

underlying assumptions, it appears inappropriate that the PFPs are subject to any limitations based on

failed nests.

DRAFT

1

M E M O R A N D U M

TO: Susan Sylvester, Chief, Water Control Operations Bureau

THROUGH: Luis Cadavid, Ph.D., P.E., Section Administrator, Operations Support Section

FROM: Cal Neidrauer, P.E., Chief Engineer, Operations Support Section Rodrigo Musalem, P.E., Lead Engineer, Operations Support Section

DATE: October 19, 2011

SUBJECT: Analysis of Portable Pump Discharge Data and Potential Spillway Capacities for Structures S-351, S-352, and S-354

Summary

An analysis was performed to estimate the volume of water released from Lake Okeechobee during times when low lake stages required temporary installation of portable pumps in the gated spillways: S-351, S-352, and S-354. The pumps are installed in the discharge bays of the gated spillways to enable conveyance of Lake water when it is anticipated that the gravity capacity of the gated spillways will be insufficient to provide the necessary conveyance to the Everglades Agricultural Area (EAA), Stormwater Treatment Areas (STAs), Lower East Coasts Service Areas (LECSAs), and the Seminole Tribe of Florida – Big Cypress Basin.

Results show that the pumps were needed during portions of the time they were installed. During those times the Lake stage was lower than the downstream canal stage and there would have been no gravity spillway capacity. However during much of the time that the pumps were installed the gravity spillway capacity would have been sufficient to convey flow equal to or greater than the pump capacities. Ignoring the 2009 event when only four pumps were installed and operated at S-352 for just 4 days before the wet season started, the additional flow from Lake Okeechobee provided by the pumps ranged from a low of 13.2 thousand acre-feet (0.04 ft from Lake O) for the 2011 event, to a high of 90.9 thousand acre-feet (0.30 ft from Lake O) for the 2007 event. The portable pumps that are temporarily installed during low Lake stage events have a small impact on Lake stage relative to the effects of evapotranspiration. The low lake stage events that required use of the portable pumps were due primarily to below-average inflow and/or implementation of the 2008 Lake Okeechobee Regulation Schedule (2008 LORS).

Introduction

Since 1931 there have been eleven low stage events in Lake Okeechobee (Figure 1). A low stage event is defined in this report as an event when the Lake stage fell below elevation 11.0 ft, NGVD. In the eleven year period since 2000, the Lake has experienced low stage events in 5 different years; the longest event occurred for 16.8 months in 2007-08. During each of those events the SFWMD temporarily installed 14 pumps in anticipation of reduced gravity spillway capacity due to low Lake stages (Figure 2). Table 1 provides details regarding the installation and removal dates and Figure 3 shows some photographs during installation. A superficial inference would be that the pumps caused the low Lake stages; such an inference is false. The analysis summarized in this memorandum demonstrates that the additional supply provided by the pumps had a small effect on Lake Okeechobee stages. The majority of the Lake stage recession during droughts is due to lack of inflows and relatively high evapotranspiration. Also of significant importance is the initial Lake stage prior to the onset of the drought condition.

2

Figure 1. Lake Okeechobee Historical Low Stage Events

Figure 2. Pump Installation Locations

4.8

0.8

16.8

6.4

2.4

2.0

3.6

2.3

2.4

4.3

1.8

0 2 4 6 8 10 12 14 16 18

20112009

2007-0820011990198219811971196219561932

Months

Lake OkeechobeeDuration Water Level was below elevation 11.0 feet, NGVD

512days (12Mar'07 to 04Aug'08)

147days (29Apr-22Sep'11)

3

Figure 3. Temporary Installation of Portable Pumps in Gated Spillway Discharge Bay.

4

Table 1. Pump Installation and Removal History

Analysis Methodology

Daily discharge data for the pumps were obtained from the SFWMD’s corporate database, DBHYDRO. Also obtained from DBHYDRO were the water surface elevations (stages) north and south of the gated spillways: S-351, S-352 and S-354. Using the established discharge rating equations and the stage data, the gravity discharge capacities of the gated spillways were calculated for the periods when the pumps were installed. Comparisons were made between the pump discharge and the gravity spillway capability. Gravity flow capability existed for many of the days when the pumps were installed. During the days when the pumps were operating if the spillway capacity was sufficient to discharge the pumped amount, then the minimum of the two was calculated as the estimated potential gravity flow. Figure 3 illustrates a graphic example of this methodology for S-352 during the 2001 drought event. Note that the estimated gravity flow capacity is likely under-estimated because if the pumps were not installed, the downstream canal stages would likely be lower, thus creating a larger stage difference across the spillway and therefore a larger discharge capacity.

Results and Discussion

Table 2 shows a summary of the pumped flow and potential gravity spillway capability for the five pump installation periods. Also shown are the average Lake stage during the event and the corresponding Lake surface area, which was used to estimate the equivalent reduction in Lake stage. The “Additional flow from Lake O” is the flow solely attributed to the operation of the pumps (“Potential Gravity Operation” minus “Pump Operation”).

Table 2 demonstrates that the additional flow from the Lake made possible by the pumps was relatively small compared with direct evaporation and transpiration (ET) from the Lake that occurred during the time the pumps were operable. For example, for the 2011 event, the total impact on the Lake from pumping was about a half-inch. ET during the same timeframe was about 4.8 inches, nearly 10 times larger.

5

Figure 3. Example of Pump and Potential Gravity Flow Capacity.

Table 2. Summary of Historical Pump Discharge and Estimated Spillway Discharge.

-2000

-1500

-1000

-500

0

500

1000

1500Fl

ow D

isch

arge

[cfs

]S352 Pump vs Gravity Flows (2001)

Estimated Gravity Flow

Actual Pump Flow

Spillway Capability

Volumes [1000 acre-ft]Pump flow = 27.4Est Gravity flow = 11.3Pump - Gravity = 16.1

Pump Operation (kaf) Potential Gravity Operation (kaf) Lake Stage & Area

Low stage event requiring pumping S-351 S-352 S-354

Total (kaf) S-351 S-352 S-354

Total (kaf)

Avg Stage (ft, NGVD)

Avg Area (1000 ac)

2001: 4/9 - 7/3 41.3 27.4 22.9 91.6 36.3 11.3 18.1 65.7 9.34 304.32007: 3/28 - 6/13 63.9 26.1 35.6 125.6 22.9 3.6 8.2 34.7 9.56 307.92008: 4/24 - 6/12 52.5 40.5 38.5 131.5 26.0 20.1 30.9 77.0 9.86 313.42009: 5/14 - 17 0.0 2.7 0.0 2.7 0.0 1.2 0.0 1.2 10.63 329.42011: 5/31 - 6/24 20.0 21.0 0.0 41.0 13.9 13.9 0.0 27.8 9.74 311.2

Additional Flow from Lake O (kaf) Equivalent Reduction in Lake stage (ft)

Low stage event requiring pumping S-351 S-352 S-354

Total (kaf) S-351 S-352 S-354

Total (feet) Total (in)

2001: 4/9 - 7/3 5.0 16.1 4.8 25.9 0.02 0.05 0.02 0.09 1.0 15.72007: 3/28 - 6/13 41.0 22.5 27.4 90.9 0.13 0.07 0.09 0.30 3.5 14.72008: 4/24 - 6/12 26.5 20.4 7.6 54.5 0.08 0.07 0.02 0.17 2.1 9.92009: 5/14 - 17 0.0 1.5 0.0 1.5 0.00 0.00 0.00 0.00 0.1 0.62011: 5/31 - 6/24 6.1 7.1 0.0 13.2 0.02 0.02 0.00 0.04 0.5 4.8

Example:2011 drought, total pump flow was 41.0 kaf. Potential gravity flow through gated spillways assuming the sameheadwater and tailwater elevation conditions was at least 27.8 kaf. The difference (41.0 - 27.8 = 13.2 kaf) is an upper estimate of the amount of water leaving Lake O that was attributable to the pumps.This 13.2 kaf is equivalent to 0.04 feet, or 0.5 inches of reduced Lake stage (average surface area of 311,000 acres). Lake O evaporation during this same period was 4.8 inches.

Lake O Evap

During Event (in)

6

Figure 4. Lake Okeechobee Low Stage Events Requiring Pumps.

Figure 4 illustrates the Lake Okeechobee stage history during the five low-stage years that required temporary installation of the pumps. The reduction in Lake stage during these events is due predominantly to evapotranspiration as is shown in Table 2. The Lake stage reduction due solely to the pumps is very small. For example, considering the largest pumping event, 2007. The portion of the 1.5 foot stage recession due to the pumps was 0.3 feet (3.5 inches); while ET during the same period was about 1.2 feet (14.7 inches).

It is important to recognize that the USACE implemented the 2008 Lake Okeechobee Regulation Schedule (2008 LORS) in May of 2008. Note from Figure 4 that the Lake stage has fallen below elevation 11.0 ft, NGVD during three of the four years that the 2008 LORS has been operative. With the exception of the inflow from Tropical Storm Fay in August 2008, below-average inflow to the Lake also contributed to the low Lake stages. However as is documented in the USACE’s EIS for the 2008 LORS, computer simulations and analyses shows that the new regulation schedule increases the duration of low Lake stage events, negatively impacts Lake ecology, increases water shortages, and adversely affects navigation. The average stage reduction due to the 2008 LORS was shown to be close to one foot.

The pumps that are temporarily installed during low Lake stage events have a relatively small impact on Lake stage considering the effects of evapotranspiration. The low lake stage events that required use of the portable pumps were due primarily to below-average inflow and/or implementation of the 2008 Lake Okeechobee Regulation Schedule (2008 LORS).

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J F M A M J J A S O N D

Lake

Sta

ge (f

eet,

NG

VD)

Lake Okeechobee Low Stage Events Requiring Pumps2001 2007 2008 2009 2011 Pumps Operable

Note: the periods highlighted in red indicate the time periods when at least one pump was operating. All the pumps were not continuously used during these time periods . Refer to Table 2 for the pump volume estimates.

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M E M O R A N D U M

TO: Beth Lewis, State Policy Chief, Office of Everglades Policy and Coordination

THROUGH: Luis Cadavid, Ph.D., P.E., Section Administrator, Operations Support Section

FROM: Cal Neidrauer, P.E., Chief Engineer, Operations Support Section

DATE: January 28, 2014

SUBJECT: Estimated changes in Lake Okeechobee stages associated with the operation of portable pumps at structures S-351, S-352, and S-354

Summary

This report summarizes the results of a follow-up analysis requested by the USFWS to address additional questions regarding the duration of reduced Lake Okeechobee stages that may result from historical operation of the portable pumps in the gated spillways: S-351, S-352, and S-354.

During low Lake Okeechobee (Lake O) stage events, portable pumps are installed in the discharge bays of the gated spillways to enable conveyance of Lake water when it is anticipated that the gravity capacity of the gated spillways will be insufficient to provide the necessary conveyance to the Everglades Agricultural Area (EAA), Stormwater Treatment Areas (STAs), Lower East Coasts Service Areas (LECSAs), and the Seminole Tribe of Florida – Big Cypress Basin.

For additional background and detail on previous analysis performed by the SFWMD to address questions regarding the volume of past pumping events and associated effect on Lake O stages, readers should refer to the October 19, 2011 SFWMD report entitled “Analysis of Portable Pump Discharge Data and Potential Spillway Capacities for Structures S-351, S-352, and S-354”. That report concluded that “the additional flow from Lake Okeechobee provided by the pumps ranged from a low of 13.2 thousand acre-feet (0.04 ft from Lake O) for the 2011 event, to a high of 90.9 thousand acre-feet (0.30 ft from Lake O) for the 2007 event. The portable pumps that are temporarily installed during low Lake stage events have a small impact on Lake stage relative to the effects of evapotranspiration. The low lake stage events that required use of the portable pumps were due primarily to below-average inflow and/or implementation of the 2008 Lake Okeechobee Regulation Schedule (2008 LORS).”

The follow-up analysis described in this report used a continuous simulation for the 2001-2011 period to evaluate the duration of changes in Lake stages. This analysis was an extension of the analysis documented in the above-mentioned October, 2011 report. The USFWS requested this information in order to more-closely examine the biological significance of the difference in Lake O stage attributed to the pump operation.

The analysis provided in this report produced simulated stage hydrographs for the continuous period 2001-2011, which includes the following five pumping events: 2001, 2007, 2008, 2009, and 2011. The 2009 event was only 4 days and the USFWS suggested this event was not necessary to evaluate further. Conclusions regarding whether or not the change in stage are meaningful biologically is not the subject of this report; that analysis is to be performed by the USFWS.

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It is important to recognize the installation and operation of the temporary pumps is in response to low Lake O stage events, not vice-versa. Low lake stage events are exacerbated by the implementation of the 2008 Lake Okeechobee Regulation Schedule. The lake stage has fallen below elevation 11.0 ft, NGVD during three of the five years that the 2008 LORS has been operative. With the exception of the inflow from Tropical Storm Fay in August 2008, below-average inflow to the lake also contributed to the low Lake stages. Furthermore, as is documented in the USACE’s EIS for the 2008 LORS, computer simulations and analyses show that the new regulation schedule increases the duration of low Lake stage events, negatively impacts Lake ecology, increases water shortages, and adversely affects navigation. The average stage reduction due to the 2008 LORS was shown to be close to one foot.

To put into proper perspective the effect of the pumping on Lake O stages, this report also estimated the Lake O stage hydrograph that would have resulted if the previous federal regulation schedule, WSE (aka, 2000 LORS), had been in effect. Results show that the need to manage lake stages at lower ranges via the 2008 LORS was a primary reason for the need to install and use the portable pumps in 2009 and in 2011.

Analysis Methodology

Simulation of the “what-if” scenarios was conducted using the simple and commonly-applied, level-pool routing methodology with a daily time-step. The method uses the fundamental continuity, or water balance, equation as follows:

∆S = S2 - S1 = RF - VET + Inflows - Outflows [1]

Where the terms are defined as follows (all units in acre-feet except as noted):

∆S = 24-hr storage change S2 = storage at end of day S1 = storage at beginning of day RF = Rainfall volume inside the HHD during the day = RF depth * Lake Area VET = VET volume = depth of ET * Lake Area [ET = ET depth (feet), A = Lake area (acres)] Inflows = total surface inflows during the day Outflows = total surface outflows during the day

The terms Inflows and Outflows are further defined as:

Inflows = Qin + Qinc Outflows = Qout + QWSc + QRGc

where: Qin=inflows assumed to not change with simulation Qinc = inflows that are changed with the simulation Qout=outflows assumed to not change with simulation QWSc=water supply outflows that are changed with simulation QRGc=regulation schedule outflows that are changed with the simulation

Including these terms in equation 1 produces:

∆S = S2 - S1 = RF - VET + Qin + Qinc – [Qout + QWSc + QRGc]

Further rearrangement yields equation 2:

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(RF + Qin – Qout) = ∆S + VET + QWSc + QRGc – Qinc [2]

For the simulated scenarios, the water balance equation is written as:

∆S’ = S’2 – S’1 = (RF + Qin – Qout) – VET’ + Qinc’ – QWSc' – QRGc’ [3]

The terms are defined above, and the prime designation (i.e., apostrophe ‘) denotes simulated values.

Notice the terms in parenthesis represent the historical values, so equation 2 is used to calculate the term, (RF + Qin – Qout) used in equation 3.

Equation 3 enables simulation of changes in storage (and stage) due to the temporary pumping and any changes in subsequent releases that depend on the simulated stage. For example if the simulated stage rises out of the water shortage band sooner than historical, then water restrictions are assumed to be lifted and unrestricted water supply releases are simulated. This example does not happen in the simulations performed for this report. Another example is if the simulated stage rises into regulation schedule bands sooner, then regulatory discharges are simulated to occur sooner.

The change in ET volume depends on the change in Lake surface area. The method used for this analysis is an approximate method to that used by the South Florida Water Management Model (SFWMM).

The daily outflow from Lake Okeechobee due to the temporary pump operation was calculated and described in the October 19, 2011 report. Those discharge time-series were used with historical Lake O stages for the simulations. Data for structure flows and evaporation were obtained from the SFWMD’s DBHYDRO database. The USACE’s stage-storage and stage-area curves for Lake O were also used.

All data and calculations are contained in an Excel workbook that will be provided along with this report to the USFWS for their subsequent ecological analyses.

Simulation Results and Discussion

Two cases were simulated for the 2001-2011 period. The first case simulated Lake O stages assuming the pumps were not used during the low lake stage events. Instead, the limited gravity flow capability of the gated spillways was used. The second case simulated the stages had the 2008LORS not been implemented in May 2008. This second simulation assumes the previous regulation schedule, 2000LORS (aka, WSE) was in effect through the entire simulation period.

The second simulation was performed to demonstrate the effects of the lower lake regulation schedule (2008LORS) on low Lake O stages. The SEIS for the 2008 LORS contains a better comparison of the simulated effects of the 2008LORS over a longer (36-year) simulation period. Nonetheless the second simulation provided in this report shows a similar pattern: increased duration and severity of low Lake O stage events caused by the 2008LORS.

Figure 1 compares Lake O stage hydrographs of the historical (with pump flow) and simulated (spillway flow without pumps) case. Also shown on Figure 1 is the simulated stage hydrograph

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if the previous Lake O regulation schedule (2000 LORS, aka WSE) were in effect during the entire simulation period.

The simulated change in Lake O stages indicates that the effect of the pumps was relatively small for all events. The 2007-2008 drought period was the extreme of the five events that occurred in the 2001-2011 period. SFWMD rainfall records dating back to 1932 confirm that 2006-2007 experienced the driest consecutive two-year rainfall totals. Further examination of rainfall data prior to 1932 suggests that 2006-2007 was the driest two-year period in the past 100 years. The lack of rainfall in 2006-07 and associated inflow to Lake Okeechobee led to the 2007-08 drought and an all-time low lake stage (8.82 feet, NGVD on 2-July-2007) and the longest duration (16.8 months) of stage below elevation 11 feet, NGVD.

The simulation of the gravity-flow (no pumps) case shows that the Lake stage reached a stage about 0.3 feet higher on 2-July-2007, and the duration of time the stage was below 11 feet was not significantly changed (501 days vs 511 days).

Of concern expressed by the USFWS was the duration of time before stages rose back to the same level as if only gravity flow were used instead of the pumps. Those durations vary considerably for the simulated events. Typically simulated stages tend to “reset” when the stage rises into the regulation schedule zones. The simulations made for this report have a similar behavior. The ecological significance of these simulated changes is to be evaluated by the USFWS.

Figure 2 illustrates the same information as Figure 1, but was plotted for the period 2006-2011 for a closer look at the extreme drought and subsequent period. The simulation of the WSE LORS shows the lake stages would have peaked in 2008 after Tropical Storm Fay at similar stages as historical. However, because the WSE LORS had higher operating zones than the 2008 LORS, the regulatory releases during 2008 and 2010 would not have been as large. The results show the lake stages would not have receded as low during the 2009 and 2011 dry periods. The 2009 event would not have required installation of the temporary pumps. And the 2011 event would likely not have required installation since the decision to do so is influenced by the lake stage and the time of year. Since the wet season traditionally starts no later than mid-June, and since the stage would have been above elevation 11.0 feet at the end of May, it is highly likely that the SFWMD would not have installed the pumps during the 2011 event.

The point of the second simulation is to illustrate the impact to low Lake stages that were caused by the 2008LORS. The portable pumps are a mitigation measure for the water supply impacts caused by implementation of the 2008LORS. Therefore it is important to evaluate impacts of the pumps in that context.

Summary

In summary, the portable pumps have been installed five times between 2001 and 2011 in response to low lake stage events; the pumps are not the cause of the low lake stage events. The analysis provided in this report confirms that the portable pumps contributed to marginally-lower lake stages during those low five lake stage events, particularly during the record low stages in 2007-2008 caused by the extreme drought. The analysis also demonstrates that the 2008 LORS is largely responsible for the need to install the pumps in 2009 and 2011. The portable pumps have been used to serve their intended purpose of providing water supplies to the EAA, STAs, Lower East Coast Service Area, and Seminole Tribe of Florida, when the gravity capability of the spillway structures is insufficient to provide the necessary conveyance capacity, as set forth in the 2007 SEIS.

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