<?xml version="1.0" encoding="us-ascii"?><InstanceReport xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"><Version>2.2.0.25</Version><hasSegments>false</hasSegments><hasScenarios>false</hasScenarios><ReportLongName>006190 - Disclosure - Evangeline Transactions</ReportLongName><DisplayLabelColumn>true</DisplayLabelColumn><ShowElementNames>false</ShowElementNames><RoundingOption /><HasEmbeddedReports>false</HasEmbeddedReports><Columns><Column><Id>1</Id><IsAbstractGroupTitle>false</IsAbstractGroupTitle><LabelColumn>false</LabelColumn><CurrencyCode /><FootnoteIndexer /><hasSegments>false</hasSegments><hasScenarios>false</hasScenarios><MCU><KeyName>1/1/2010 - 12/31/2010
</KeyName><CurrencySymbol /><contextRef><ContextID>c00052</ContextID><EntitySchema>http://www.sec.gov/CIK</EntitySchema><EntityValue>0001089819</EntityValue><PeriodDisplayName /><PeriodType>duration</PeriodType><PeriodStartDate>2010-01-01T00:00:00</PeriodStartDate><PeriodEndDate>2010-12-31T00:00:00</PeriodEndDate><Segments /><Scenarios /></contextRef><UPS /><CurrencyCode /><OriginalCurrencyCode /></MCU><CurrencySymbol /><Labels><Label Id="1" Label="12 Months Ended" /><Label Id="2" Label="Dec. 31, 2010" /></Labels></Column></Columns><Rows><Row><Id>2</Id><IsAbstractGroupTitle>true</IsAbstractGroupTitle><Level>0</Level><ElementName>cnl_NotesToFinancialStatementsAbstract</ElementName><ElementPrefix>cnl</ElementPrefix><IsBaseElement>false</IsBaseElement><BalanceType>na</BalanceType><PeriodType>duration</PeriodType><ShortDefinition>No definition available.</ShortDefinition><IsReportTitle>false</IsReportTitle><IsSegmentTitle>false</IsSegmentTitle><IsSubReportEnd>false</IsSubReportEnd><IsCalendarTitle>false</IsCalendarTitle><IsTuple>false</IsTuple><IsEquityPrevioslyReportedAsRow>false</IsEquityPrevioslyReportedAsRow><IsEquityAdjustmentRow>false</IsEquityAdjustmentRow><IsBeginningBalance>false</IsBeginningBalance><IsEndingBalance>false</IsEndingBalance><IsReverseSign>false</IsReverseSign><PreferredLabelRole /><FootnoteIndexer /><Cells><Cell><Id>1</Id><IsNumeric>false</IsNumeric><IsRatio>false</IsRatio><DisplayZeroAsNone>false</DisplayZeroAsNone><NumericAmount>0</NumericAmount><RoundedNumericAmount>0</RoundedNumericAmount><NonNumbericText /><NonNumericTextHeader /><FootnoteIndexer /><CurrencyCode /><CurrencySymbol /><IsIndependantCurrency>false</IsIndependantCurrency><ShowCurrencySymbol>false</ShowCurrencySymbol><DisplayDateInUSFormat>false</DisplayDateInUSFormat><hasSegments>false</hasSegments><hasScenarios>false</hasScenarios></Cell></Cells><OriginalInstanceReportColumns /><Unit>Other</Unit><ElementDataType>xbrli:stringItemType</ElementDataType><SimpleDataType>string</SimpleDataType><ElementDefenition>No definition available.</ElementDefenition><IsTotalLabel>false</IsTotalLabel><IsEPS>false</IsEPS><Label>Notes to the Financial Statements [Abstract]</Label></Row><Row><Id>3</Id><IsAbstractGroupTitle>false</IsAbstractGroupTitle><Level>0</Level><ElementName>cnl_Evangelinetransactions</ElementName><ElementPrefix>cnl</ElementPrefix><IsBaseElement>false</IsBaseElement><BalanceType>na</BalanceType><PeriodType>duration</PeriodType><ShortDefinition>Effects of termination operating lease and execution of new operating lease. Including (1) description of new lease terms,...</ShortDefinition><IsReportTitle>false</IsReportTitle><IsSegmentTitle>false</IsSegmentTitle><IsSubReportEnd>false</IsSubReportEnd><IsCalendarTitle>false</IsCalendarTitle><IsTuple>false</IsTuple><IsEquityPrevioslyReportedAsRow>false</IsEquityPrevioslyReportedAsRow><IsEquityAdjustmentRow>false</IsEquityAdjustmentRow><IsBeginningBalance>false</IsBeginningBalance><IsEndingBalance>false</IsEndingBalance><IsReverseSign>false</IsReverseSign><PreferredLabelRole>terselabel</PreferredLabelRole><FootnoteIndexer /><Cells><Cell><Id>1</Id><IsNumeric>false</IsNumeric><IsRatio>false</IsRatio><DisplayZeroAsNone>false</DisplayZeroAsNone><NumericAmount>0</NumericAmount><RoundedNumericAmount>0</RoundedNumericAmount><NonNumbericText>&lt;div style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; MARGIN-RIGHT: 0pt; TEXT-ALIGN: left" align="left"&gt;&lt;font style="DISPLAY: inline; FONT-WEIGHT: bold; FONT-SIZE: 9pt; FONT-FAMILY: Helvetica LT Std Cond, sans-serif"&gt;Note 18 &amp;#8212; Evangeline Transactions &lt;/font&gt; &lt;div&gt;&lt;hr style="COLOR: black" align="left" width="100%" noshade="noshade" size="1" /&gt;&lt;/div&gt;&lt;/div&gt;&lt;div style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; MARGIN-RIGHT: 0pt; TEXT-ALIGN: left"&gt;&lt;div style="DISPLAY: block; TEXT-INDENT: 0pt"&gt;&lt;font style="DISPLAY: inline; FONT-SIZE: 9pt; FONT-FAMILY: Helvetica LT Std Light, sans-serif"&gt;On February 22, 2010, Evangeline and JPMVEC entered into the Evangeline Restructuring Agreement whereby the parties agreed to terminate the existing Evangeline Tolling Agreement and entered into the Evangeline 2010 Tolling Agreement, effective March 1, 2010.&amp;#160;&amp;#160;The other significant terms of the Evangeline Restructuring Agreement are:&lt;/font&gt;&lt;/div&gt;&lt;/div&gt;&lt;div style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; MARGIN-RIGHT: 0pt; TEXT-ALIGN: left" align="justify"&gt;&amp;#160;&lt;/div&gt;&lt;div style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; MARGIN-RIGHT: 0pt; TEXT-ALIGN: left"&gt;&lt;table cellspacing="0" cellpadding="0" width="100%"&gt;&lt;tr valign="top"&gt;&lt;td style="WIDTH: 27pt" align="right"&gt;&lt;div&gt;&lt;font style="DISPLAY: inline; FONT-SIZE: 9pt; FONT-FAMILY: Wingdings"&gt;&amp;#167;&amp;#160;&amp;#160;&lt;/font&gt;&lt;/div&gt;&lt;/td&gt;&lt;td&gt;&lt;div style="MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; MARGIN-RIGHT: 0pt" align="justify"&gt;&lt;font style="DISPLAY: inline; FONT-SIZE: 9pt; FONT-FAMILY: Helvetica LT Std Light, sans-serif"&gt;The tolling agreement is a market-based tolling agreement, for Coughlin Units 6 and 7, ending December 31, 2011, with an option for JPMVEC to extend the term through December 31, 2012.&amp;#160;&amp;#160;The agreement also gives Evangeline the right to terminate its Coughlin Unit 6 obligations prior to the expiration of the term;&lt;/font&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;&lt;/table&gt;&lt;/div&gt;&lt;div style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; MARGIN-RIGHT: 0pt; TEXT-ALIGN: left"&gt;&lt;table cellspacing="0" cellpadding="0" width="100%"&gt;&lt;tr valign="top"&gt;&lt;td style="WIDTH: 27pt" align="right"&gt;&lt;div&gt;&lt;font style="DISPLAY: inline; FONT-SIZE: 9pt; FONT-FAMILY: Wingdings"&gt;&amp;#167;&amp;#160;&amp;#160;&lt;/font&gt;&lt;/div&gt;&lt;/td&gt;&lt;td&gt;&lt;div style="MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; MARGIN-RIGHT: 0pt" align="justify"&gt;&lt;font style="DISPLAY: inline; FONT-SIZE: 9pt; FONT-FAMILY: Helvetica LT Std Light, sans-serif"&gt;$126.6 million of Evangeline&amp;#8217;s 8.82% Senior Secured bonds due 2019, owned by JPMVEC, were transferred to Evangeline and subsequently retired; and $5.3 million of&amp;#160;&lt;/font&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;&lt;/table&gt;&lt;/div&gt;&lt;div style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; MARGIN-RIGHT: 0pt; TEXT-ALIGN: left"&gt;&lt;div style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; MARGIN-RIGHT: 0pt; TEXT-ALIGN: left"&gt;&lt;table cellspacing="0" cellpadding="0" width="100%"&gt;&lt;tr valign="top"&gt;&lt;td style="WIDTH: 27pt" align="right"&gt;&lt;div&gt;&lt;font style="DISPLAY: inline; FONT-SIZE: 9pt; FONT-FAMILY: Wingdings"&gt;&amp;#160;&amp;#160;&lt;/font&gt;&lt;/div&gt;&lt;/td&gt;&lt;td&gt;&lt;div style="MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; MARGIN-RIGHT: 0pt" align="justify"&gt;&lt;font style="DISPLAY: inline; FONT-SIZE: 9pt; FONT-FAMILY: Helvetica LT Std Light, sans-serif"&gt;&amp;#160;accrued interest associated with the bonds transferred to Evangeline was eliminated; &lt;/font&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;&lt;/table&gt;&lt;/div&gt;&lt;/div&gt;&lt;div style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; MARGIN-RIGHT: 0pt; TEXT-ALIGN: left"&gt;&lt;table cellspacing="0" cellpadding="0" width="100%"&gt;&lt;tr valign="top"&gt;&lt;td style="WIDTH: 27pt" align="right"&gt;&lt;div&gt;&lt;font style="DISPLAY: inline; FONT-SIZE: 9pt; FONT-FAMILY: Wingdings"&gt;&amp;#167;&amp;#160;&amp;#160;&lt;/font&gt;&lt;/div&gt;&lt;/td&gt;&lt;td&gt;&lt;div style="MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; MARGIN-RIGHT: 0pt" align="justify"&gt;&lt;font style="DISPLAY: inline; FONT-SIZE: 9pt; FONT-FAMILY: Helvetica LT Std Light, sans-serif"&gt;JPMVEC paid Evangeline $56.7 million; &lt;/font&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;&lt;/table&gt;&lt;/div&gt;&lt;div style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; MARGIN-RIGHT: 0pt; TEXT-ALIGN: left"&gt;&lt;table cellspacing="0" cellpadding="0" width="100%"&gt;&lt;tr valign="top"&gt;&lt;td style="WIDTH: 27pt" align="right"&gt;&lt;div&gt;&lt;font style="DISPLAY: inline; FONT-SIZE: 9pt; FONT-FAMILY: Wingdings"&gt;&amp;#167;&amp;#160;&amp;#160;&lt;/font&gt;&lt;/div&gt;&lt;/td&gt;&lt;td&gt;&lt;div style="MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; MARGIN-RIGHT: 0pt" align="justify"&gt;&lt;font style="DISPLAY: inline; FONT-SIZE: 9pt; FONT-FAMILY: Helvetica LT Std Light, sans-serif"&gt;JPMVEC returned Cleco Corporation&amp;#8217;s $15.0 million letter of credit issued under the Evangeline Tolling Agreement and the letter of credit was cancelled; and&lt;/font&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;&lt;/table&gt;&lt;/div&gt;&lt;div style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; MARGIN-RIGHT: 0pt; TEXT-ALIGN: left"&gt;&lt;table cellspacing="0" cellpadding="0" width="100%"&gt;&lt;tr valign="top"&gt;&lt;td style="WIDTH: 27pt" align="right"&gt;&lt;div&gt;&lt;font style="DISPLAY: inline; FONT-SIZE: 9pt; FONT-FAMILY: Wingdings"&gt;&amp;#167;&amp;#160;&amp;#160;&lt;/font&gt;&lt;/div&gt;&lt;/td&gt;&lt;td&gt;&lt;div style="MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; MARGIN-RIGHT: 0pt" align="justify"&gt;&lt;font style="DISPLAY: inline; FONT-SIZE: 9pt; FONT-FAMILY: Helvetica LT Std Light, sans-serif"&gt;Evangeline recorded a gain of $148.4 million.&lt;/font&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;&lt;/table&gt;&lt;/div&gt;&lt;div style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; MARGIN-RIGHT: 0pt; TEXT-ALIGN: left" align="justify"&gt;&amp;#160;&lt;/div&gt;&lt;div style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 18pt; MARGIN-RIGHT: 0pt; TEXT-ALIGN: left" align="left"&gt;&lt;font style="DISPLAY: inline; FONT-SIZE: 9pt; FONT-FAMILY: Helvetica LT Std Light, sans-serif"&gt;The termination of the Evangeline Tolling Agreement was considered a termination of an operating lease and a triggering event requiring an asset impairment analysis.&amp;#160;&amp;#160;Management made assumptions about expected future cash flows, long-term interest rates, estimates about the probability of the occurrence of future events, and estimates of market values of assets without a readily observable market price.&amp;#160;&amp;#160;An impairment charge was not recorded since the undiscounted expected future net cash flows exceeded the carrying value of Evangeline&amp;#8217;s property, plant and equipment. &lt;font style="DISPLAY: inline; FONT-SIZE: 9pt; FONT-FAMILY: Helvetica LT Std Light, sans-serif"&gt;Due to the lack of a long-term agreement, the expected future net cash flows of Evangeline are subject to an increased potential for variability as compared to prior years.&amp;#160;&amp;#160;Consequently, future impairment tests could occur more frequently and might result in an impairment charge.&lt;/font&gt;&lt;/font&gt;&lt;/div&gt;&lt;div style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 18pt; MARGIN-RIGHT: 0pt; TEXT-ALIGN: left" align="left"&gt;&lt;font style="DISPLAY: inline; FONT-SIZE: 9pt; FONT-FAMILY: Helvetica LT Std Light, sans-serif"&gt;Under the terms of the Evangeline Restructuring Agreement, Evangeline issued an irrevocable redemption notice to redeem the remaining $35.2 million of 8.82% Senior Secured bonds outstanding pursuant to their terms on February 25, 2010, and paid the debtholders $1.5 million of accrued interest and a $10.2 million make-whole payment.&amp;#160;&amp;#160;As a result of the debt retirement, Evangeline expensed $2.1 million in unamortized debt issuance costs associated with the Evangeline bonds.&amp;#160;&amp;#160;The Evangeline bonds were non-recourse to Cleco Corporation and redemption of the bonds was permitted under Cleco Corporation&amp;#8217;s revolving credit facility.&amp;#160;&amp;#160;Upon the redemption of the bonds, $30.1 million of restricted cash was released to Evangeline.&amp;#160;&amp;#160;&lt;/font&gt;&lt;/div&gt;&lt;div style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 18pt; MARGIN-RIGHT: 0pt; TEXT-ALIGN: left" align="left"&gt;&lt;font style="DISPLAY: inline; FONT-SIZE: 9pt; FONT-FAMILY: Helvetica LT Std Light, sans-serif"&gt;The impacts of these transactions are reflected in the Midstream segment, which includes Evangeline.&amp;#160;&amp;#160;In accordance with the authoritative guidance, effective January 1, 2010, the financial results for Evangeline are no longer presented as equity income (loss), but presented in the corresponding line items in the consolidated financials of Midstream.&lt;/font&gt;&lt;/div&gt;</NonNumbericText><NonNumericTextHeader>Note 18 &amp;#8212; Evangeline Transactions  On February 22, 2010, Evangeline and JPMVEC entered into the Evangeline Restructuring Agreement whereby the parties</NonNumericTextHeader><FootnoteIndexer /><CurrencyCode /><CurrencySymbol /><IsIndependantCurrency>false</IsIndependantCurrency><ShowCurrencySymbol>false</ShowCurrencySymbol><DisplayDateInUSFormat>false</DisplayDateInUSFormat><hasSegments>false</hasSegments><hasScenarios>false</hasScenarios></Cell></Cells><OriginalInstanceReportColumns /><Unit>Other</Unit><ElementDataType>us-types:textBlockItemType</ElementDataType><SimpleDataType>string</SimpleDataType><ElementDefenition>Effects of termination operating lease and execution of new operating lease. 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