Exhibit 99.1

CenterPoint Energy reports second-quarter 2015 earnings of

$0.18 per diluted share; reaffirms full-year guidance of

$1.00 – $1.10 per diluted share

Houston, TX – August 10, 2015 - CenterPoint Energy, Inc. (NYSE: CNP) today reported net income of $77 million, or $0.18 per diluted share, for the second quarter of 2015, compared with $107 million, or $0.25 per diluted share for the same period of the prior year. On a guidance basis, for the second quarter 2015, CenterPoint Energy earned 19 cents per diluted share consisting of 13 cents from utility operations and 6 cents from midstream investments.

Utility operations produced $186 million of operating income for the second quarter of 2015, equal to operating income for the same quarter of the prior year. Equity income from midstream investments was $43 million for the second quarter of 2015, compared with $71 million for the same period in the prior year.

“We remain focused on investing in infrastructure to meet the needs of our growing customer base. Our utilities delivered strong financial results, and we continue to seek timely recovery of our investments,” said Scott M. Prochazka, president and chief executive officer of CenterPoint Energy. “Additionally, Enable is performing as expected in a challenging commodity market, and we remain confident in their growth strategy.”

Business Segments

Electric Transmission & Distribution

The electric transmission & distribution segment reported operating income of $158 million for the second quarter of 2015, consisting of $131 million from the regulated electric transmission & distribution utility operations (TDU) and $27 million related to securitization bonds. Operating income for the second quarter of 2014 was $145 million, consisting of $115 million from the TDU and $30 million related to securitization bonds.

-more-

Page 2 of 6        

Operating income for the TDU benefited primarily from higher usage largely due to a return to more normal weather ($13 million), higher net transmission-related revenues ($8 million) and continued strong customer growth ($5 million). These benefits were partially offset by reduced equity return related to true-up proceeds ($5 million).

Natural Gas Distribution

The natural gas distribution segment reported operating income of $19 million for the second quarter of 2015, compared with $30 million for the same period of 2014. Operating income was lower, primarily due to reduced usage as a result of colder than normal weather in 2014 ($5 million) and higher depreciation expense ($6 million).

Energy Services

The energy services segment reported operating income of $9 million for the second quarter of 2015, which included a mark-to-market accounting gain of $2 million, compared with $11 million for the same period of 2014, which included a mark-to-market accounting gain of $6 million. Excluding mark-to-market accounting gains, the $2 million increase in operating income in the second quarter of 2015 was due to improved margins and a decrease in operation and maintenance expenses.

Midstream Investments

The midstream investments segment reported $43 million of equity income for the second quarter of 2015, compared with $71 million in the same quarter of the prior year.

Cash distributions received in the second quarter of 2015 were $73 million. Further, Enable Midstream declared a quarterly cash distribution on July 22, 2015, from which CenterPoint Energy expects to receive approximately $74 million. This represents an increase of approximately 1.1 percent over the prior quarterly distribution.

Enable Midstream provided outlook for per unit distributions to grow at 3-7 percent annually through 2017. Please refer to their August 5, 2015, earnings press release for details.

Dividend Declaration

On July 24, 2015, CenterPoint Energy’s board of directors declared a regular quarterly cash dividend of $0.2475 per share of common stock payable on September 10, 2015, to shareholders of record as of the close of business on August 14, 2015.

Dividend Growth Outlook

CenterPoint Energy is targeting 4-6 percent annual earnings per share growth on a guidance basis through 2018, inclusive of midstream investments, and anticipates dividend growth to be in line with EPS growth. CenterPoint Energy remains committed to providing a secure dividend with stable, competitive growth. Consistent with this strategy, CenterPoint Energy’s board of directors will continue to review quarterly dividends, which will be based upon factors such as recent and projected earnings growth and financial liquidity.

-more-

Page 3 of 6        

Outlook for 2015

CenterPoint Energy reaffirms that its earnings estimate for 2015 utility operations is in the range of $0.71 - $0.75 per diluted share. The company expects its 2015 earnings estimate from midstream investments to be in the range of $0.29 - $0.35 per diluted share. On a consolidated basis, CenterPoint Energy reaffirms earnings on a guidance basis for 2015 in the range of $1.00 - $1.10 per diluted share. We anticipate utility operations earnings for 2015 near the high end of the range while midstream investments’ earnings are anticipated to be near the low end of the range provided.

The utility operations guidance range considers performance to date and certain significant variables that may impact earnings, such as weather, regulatory and judicial proceedings, throughput, commodity prices, effective tax rates, and financing activities. In providing this guidance, the company does not include other potential impacts, such as changes in accounting standards or unusual items, earnings from the change in the value of the ZENS securities and the related stocks, or the timing effects of mark-to-market accounting in the company’s energy service business.

In providing guidance for equity investments in midstream operations, the company assumes a 55.4 percent limited partner ownership interest in Enable Midstream and includes the amortization of our basis differential in Enable Midstream. The company’s guidance takes into account such factors as Enable Midstream’s most recent public outlook for 2015 dated August 5, 2015, and effective tax rates. The company does not include other potential impacts such as any changes in accounting standards or Enable Midstream’s unusual items.

Page 4 of 6        

CenterPoint Energy, Inc. and Subsidiaries

Reconciliation of Net Income and diluted EPS to the basis used in providing 2015 annual earnings guidance

Page 5 of 6        

Filing of Form 10-Q for CenterPoint Energy, Inc.

Today, CenterPoint Energy, Inc. filed with the Securities and Exchange Commission (SEC) its Quarterly Report on Form 10-Q for the period ended June 30, 2015. A copy of that report is available on the company’s website, under the Investors section. Other filings the company makes with the SEC and certain documents relating to its corporate governance can also be found under the Investors section.

Webcast of Earnings Conference Call

CenterPoint Energy’s management will host an earnings conference call on Monday, August 10, 2015, at 10:30 a.m. Central time or 11:30 a.m. Eastern time. Interested parties may listen to a live audio broadcast of the conference call on the company’s website under the Investors section. A replay of the call can be accessed approximately two hours after the completion of the call and will be archived on the website for at least one year.

CenterPoint Energy, Inc., headquartered in Houston, Texas, is a domestic energy delivery company that includes electric transmission & distribution, natural gas distribution and energy services operations. The company serves more than five million metered customers primarily in Arkansas, Louisiana, Minnesota, Mississippi, Oklahoma, and Texas. The company also owns a 55.4 percent limited partner interest in Enable Midstream Partners, a publicly traded master limited partnership it jointly controls with OGE Energy Corp., which owns, operates and develops natural gas and crude oil infrastructure assets. With more than 7,400 employees, CenterPoint Energy and its predecessor companies have been in business for more than 140 years. For more information, visit the website at www.CenterPointEnergy.com.

This news release includes forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. These forward-looking statements are based upon assumptions of management which are believed to be reasonable at the time made and are subject to significant risks and uncertainties. Actual events and results may differ materially from those expressed or implied by these forward-looking statements. Any statements in this news release regarding future earnings, and future financial performance and results of operations, including, but not limited to earnings guidance, targeted dividend growth rate and any other statements that are not historical facts are forward-looking statements. Each forward-looking statement contained in this news release speaks only as of the date of this release. Factors that could affect actual results include (1) state and federal legislative and regulatory actions or developments affecting various aspects of CenterPoint Energy’s businesses (including the businesses of Enable Midstream Partners (Enable Midstream)), including, among others, energy deregulation or re-regulation, pipeline integrity and safety, health care reform, financial reform, tax legislation, and actions regarding the rates charged by CenterPoint Energy’s regulated businesses; (2) state and federal legislative and regulatory actions or developments relating to the environment, including those related to global climate change; (3) timely and appropriate rate actions that allow recovery of costs and a reasonable return on investment; (4) the timing and outcome of any audits, disputes or other proceedings related to taxes; (5) problems with construction, implementation of necessary technology or other issues with respect to major capital projects that result in delays or in cost overruns that cannot be recouped in rates; (6) industrial, commercial and residential growth in CenterPoint Energy’s service territories and changes in market demand, including the effects of energy efficiency measures and demographic patterns; (7) the timing and extent of changes in commodity prices, particularly natural gas and natural gas liquids, and the effects of geographic and seasonal commodity price differentials, and the impact of commodity changes on producer related activities; (8) weather variations and other natural phenomena, including the impact on operations and capital from severe weather events; (9) any direct or indirect effects on CenterPoint Energy’s facilities, operations and financial condition resulting from terrorism, cyber-attacks, data security breaches or other attempts to disrupt its businesses or the businesses of third parties, or other catastrophic events; (10) the impact of unplanned facility outages; (11) timely and appropriate regulatory actions allowing securitization or other recovery of costs associated with any future hurricanes or natural disasters; (12) changes in interest rates or rates of inflation; (13) commercial bank and financial market conditions, CenterPoint Energy’s access to capital, the cost of such capital, and the results of its financing and refinancing efforts, including availability of funds in the debt capital markets; (14) actions by credit rating agencies; (15) effectiveness of CenterPoint Energy’s risk

Page 6 of 6        

management activities; (16) inability of various counterparties to meet their obligations; (17) non-payment for services due to financial distress of CenterPoint Energy’s customers; (18) the ability of GenOn Energy, Inc. (formerly known as RRI Energy, Inc.), a wholly owned subsidiary of NRG Energy, Inc., and its subsidiaries to satisfy their obligations to CenterPoint Energy and its subsidiaries; (19) the ability of retail electric providers, and particularly the largest customers of the TDU, to satisfy their obligations to CenterPoint Energy and its subsidiaries; (20) the outcome of litigation brought by or against CenterPoint Energy or its subsidiaries; (21) CenterPoint Energy’s ability to control costs, invest planned capital, or execute growth projects; (22) the investment performance of pension and postretirement benefit plans; (23) potential business strategies, including restructurings, joint ventures, and acquisitions or dispositions of assets or businesses, for which no assurance can be given that they will be completed or will provide the anticipated benefits to CenterPoint Energy; (24) acquisition and merger activities involving CenterPoint Energy or its competitors; (25) future economic conditions in regional and national markets and their effects on sales, prices and costs; (26) the performance of Enable Midstream, the amount of cash distributions CenterPoint Energy receives from Enable Midstream, and the value of its interest in Enable Midstream, and factors that may have a material impact on such performance, cash distributions and value, including certain of the factors specified above and: (A) the integration of the operations of the businesses contributed to Enable Midstream; (B) the achievement of anticipated operational and commercial synergies and expected growth opportunities, and the successful implementation of Enable Midstream’s business plan; (C) competitive conditions in the midstream industry, and actions taken by Enable Midstream’s customers and competitors, including the extent and timing of the entry of additional competition in the markets served by Enable Midstream; (D) the timing and extent of changes in the supply of natural gas and associated commodity prices, particularly natural gas and natural gas liquids, the competitive effects of the available pipeline capacity in the regions served by Enable Midstream, and the effects of geographic and seasonal commodity price differentials, including the effects of these circumstances on re-contracting available capacity on Enable Midstream’s interstate pipelines; (E) the demand for natural gas, NGLs and transportation and storage services; (F) changes in tax status; (G) access to growth capital; and (H) the availability and prices of raw materials for current and future construction projects; (27) effective tax rate; (28) other factors discussed in CenterPoint Energy’s Annual Report on Form 10-K for the fiscal year ended December 31, 2014, as well as in CenterPoint Energy’s Quarterly Report on Form 10-Q for the quarter ended March 31, 2015, and June 30, 2015, and other reports CenterPoint Energy or its subsidiaries may file from time to time with the Securities and Exchange Commission.

Use of Non-GAAP Financial Measures

In addition to presenting its financial results in accordance with generally accepted accounting principles (GAAP), CenterPoint Energy also provides guidance based on adjusted diluted earnings per share, which is a non-GAAP financial measure. Generally, a non-GAAP financial measure is a numerical measure of a company’s historical or future financial performance that excludes or includes amounts that are not normally excluded or included in the most directly comparable GAAP financial measure. A reconciliation of net income and diluted earnings per share to the basis used in providing 2015 guidance is provided in this news release.

Management evaluates financial performance in part based on adjusted diluted earnings per share and believes that presenting this non-GAAP financial measure enhances an investor’s understanding of CenterPoint Energy’s overall financial performance by providing them with an additional meaningful and relevant comparison of current and anticipated future results across periods by excluding items that Management does not believe most accurately reflect its fundamental business performance, which items include the items reflected in the reconciliation table of this news release. This non-GAAP financial measure should be considered as a supplement and complement to, and not as a substitute for, or superior to, the most directly comparable GAAP financial measure and may be different than non-GAAP financial measures used by other companies.

###

CenterPoint Energy, Inc. and Subsidiaries

Statements of Consolidated Income

(Millions of Dollars)

(Unaudited)

Reference is made to the Notes to the Consolidated Financial Statements

contained in the Quarterly Report on Form 10-Q of CenterPoint Energy, Inc.

CenterPoint Energy, Inc. and Subsidiaries

Selected Data From Statements of Consolidated Income

(Millions of Dollars, Except Share and Per Share Amounts)

(Unaudited)

Reference is made to the Notes to the Consolidated Financial Statements

contained in the Quarterly Report on Form 10-Q of CenterPoint Energy, Inc.

CenterPoint Energy, Inc. and Subsidiaries

Results of Operations by Segment

(Millions of Dollars)

(Unaudited)

Reference is made to the Notes to the Consolidated Financial Statements

contained in the Quarterly Report on Form 10-Q of CenterPoint Energy, Inc.

CenterPoint Energy, Inc. and Subsidiaries

Results of Operations by Segment

(Millions of Dollars)

(Unaudited)

Capital Expenditures by Segment

(Millions of Dollars)

(Unaudited)

Interest Expense Detail

(Millions of Dollars)

(Unaudited)

Reference is made to the Notes to the Consolidated Financial Statements

contained in the Quarterly Report on Form 10-Q of CenterPoint Energy, Inc.

CenterPoint Energy, Inc. and Subsidiaries

Condensed Consolidated Balance Sheets

(Millions of Dollars)

(Unaudited)

Reference is made to the Notes to the Consolidated Financial Statements

contained in the Quarterly Report on Form 10-Q of CenterPoint Energy, Inc.

CenterPoint Energy, Inc. and Subsidiaries

Condensed Statements of Consolidated Cash Flows

(Millions of Dollars)

(Unaudited)

Reference is made to the Notes to the Consolidated Financial Statements

contained in the Quarterly Report on Form 10-Q of CenterPoint Energy, Inc.