Exhibit 99.1

For Immediate Release

GLOBAL WATER RESOURCES, INC. REPORTS

FIRST QUARTER 2016 RESULTS

PHOENIX, AZ – June 9, 2016 – Global Water Resources, Inc. (NASDAQ: GWRS, TSX: GWR) (the “Company”), a water resource management company that owns and operates regulated water, wastewater and recycled water utilities in the metropolitan Phoenix area, today reported its first quarter financial results for the period ended March 31, 2016¹. All amounts, unless otherwise indicated, are in U.S. dollars. See information below regarding today’s conference call information.

First Quarter 2016 Highlights

Highlights Subsequent to Quarter End

“Since the start of the year, we have successfully executed on a series of milestones that have considerably strengthened and improved our core business,” said Ron Fleming, President and CEO of Global Water. “Additionally, we signed a note purchase agreement for the restructuring of our debt on more favorable terms, which we expect to result in a significant reduction to interest expense and an improvement to our bottom line beginning in Q3-2016.”

Mr. Fleming added, “This progress, combined with our successful IPO and improving economic conditions in the Phoenix area, means that we are well positioned to capitalize on strategic opportunities.”

Summary of Financial Results

Consolidated Revenue

Consolidated revenue for Q1-2016 was $6.8 million, down 10.6% or $0.8 million from $7.6 million for the same period of 2015. Global Water’s results for Q1-2015 included the results of our Valencia operations, which the Company transferred to the City of Buckeye in July 2015.

Excluding Valencia, Global Water grew revenue by 6.0% or $384,000 in Q1-2016 from last year. The growth was primarily driven by a 2.3% increase in active connections, increased rates, and a 10.3% increase in water consumption during the quarter.

Operating Expenses

Operating expenses for Q1-2016 were $5.7 million, down $1.1 million when compared to $6.8 million for Q1-2015. The decrease in operating expenses was primarily attributable to lower operations and maintenance costs as a result of the disposition of Valencia.

Excluding the impact of Valencia, operating expenses in Q1-2016 were relatively flat compared to Q1-2015.

EBITDA

EBITDA for Q1-2016 was relatively flat at $2.9 million compared to $2.9 million for the same period of last year. EBITDA was flat primarily due to the lost EBITDA associated with the Valencia disposition which was then offset by increased rates, increased connections and increased water consumption.

Excluding the impact of Valencia, EBITDA for Q1-2016 was $2.9 million compared to $2.3 million in Q1-2015, which reflects a $587,000 increase or 25% improvement.

Adjusted EBITDA

Adjusted EBITDA was slightly down for Q1-2016 at $3.1 million compared to $3.2 million for the same period last year. The slight decline was primarily due to the Valencia disposition offset by increased rates, increased connections and increased water consumption.

Excluding the impact of Valencia, Adjusted EBITDA for Q1-2016 was $3.1 million compared to $2.5 million in Q1-2015, which reflects a $555,000 increase or 22% improvement.

Net Income/Loss

Global Water incurred a net loss of $0.3 million or $0.02 per basic share in Q1-2016. This compares to a net loss of $0.9 million or $0.05 per share for Q1-2015. The $0.6 million improvement in net loss was due to a number of factors, including a reduction in interest charges stemming from the retirement of a loan as a result of the Valencia condemnation.

Favorable Private Letter Ruling

We recently received a favorable Private Letter Ruling (PLR) from the IRS as it pertains to the tax treatment of our gain on the Valencia condemnation. Specifically, the IRS ruled that we can make capital investments in our existing utilities (water and wastewater) which would qualify under IRC Section 1033 re-investment requirements. The corporate tax rate on the gain currently stands at roughly 38%, so to the extent we make qualifying capital investments, this will allow us to defer the gain and reduce the associated tax payments that otherwise would have come due by approximately 38%. The time horizon

to make these capital investments is two years from the end of the tax year in which the gain is realized (possibly three years with an IRS approval to extend one year).

Although not part of the PLR, in addition to making capital investments, we can also make acquisitions of other like kind property (i.e. water and wastewater utilities) that would qualify under IRC Section 1033, to similarly defer the gain and the taxes that would become due. The time horizon to make these qualifying acquisitions is three years from the end of the tax year in which the gain is realized (with the ability to apply for extensions in one year increments).

Business Outlook

Global Water’s immediate growth strategy for its regulated water, wastewater and recycled water business is driven by increased service connections, continued operating efficiencies and utility rate increases approved by the Arizona Corporate Commission (ACC). Global Water now has the opportunity to return to its original mission, to aggregate water and wastewater utilities, allowing our customers and the Company to realize the benefits of consolidation, regionalization, and environmental stewardship, which it may pursue as opportunities arise.

Connection Rates

Excluding the impact of the Valencia operations, Global Water experienced positive growth in new connections and in re-establishing service on previously vacant homes. As of March 31, 2016, active service connections increased by 201 to 37,985, compared with 37,784 as of December 31, 2015. This represents an annualized increase of 2.1%. The Company’s vacancy rate is now at 2.3% after reaching a peak of 11.2% in February of 2009.

Arizona’s Growth Corridor: Positive Population Trends

The Metropolitan Phoenix area is steadily growing due to low-cost housing, excellent weather, large and growing universities, a diverse employment base and low taxes. Its population has increased throughout 2015 and into 2016, and it continues to grow.

The Arizona Department of Administration – Office of Employment and Population Statistics predicts that Maricopa County will have a population of 4.5 million by 2020. This rate of growth, combined with more than five additional years of rate phase-ins, will create the opportunity for Global Water to meaningfully increase its active connections and regulated revenues for the foreseeable future.

Conference Call

Global Water will conduct a conference call on Thursday, June 9, 2016, at 1:00 p.m. EST. Interested persons may access the call by dialing (647) 427-7450 or toll free at (888) 231-8191. Shortly after the conclusion of the call, a replay will be available by dialing (416) 849-0833 or (855) 859-2056. The passcode is 16104190. The replay will expire at midnight (EST) on June 23, 2016. A copy of the transcript and an audio replay of the conference call, once available, will be archived within the investor section of the Company’s web site at www.gwresources.com.

About Global Water Resources, Inc.

The Company is a water resource management company located in Phoenix, Arizona, that owns and operates regulated water, wastewater and recycled water utilities in the metropolitan Phoenix area. More information on the Company can be found at www.gwresources.com.

Cautionary Note Regarding Forward-Looking Statements

This press release includes certain forward-looking statements which reflect the Company’s expectations regarding future events. The forward-looking statements involve a number of assumptions, risks, uncertainties and other factors that could cause actual results to differ materially from those contained in

the forward-looking statements. These forward-looking statements include, but are not limited to, the timing of closing of the note sale, reductions to interest expense, improvements to our bottom line, population predictions, increases in active connections, increases in regulated revenue and other statements that are not historical facts as well as statements identified by words such as “expects”, “anticipates”, “intends”, “plans”, “believes”, “seeks”, “estimates”, or the negative of these terms, or other words of similar meaning. These statements are based on our current beliefs or expectations and are inherently subject to a number of risks, uncertainties and assumptions, most of which are difficult to predict and many of which are beyond our control. Actual results may differ materially from these expectations due to changes in political, economic, business, market, regulatory and other factors. Accordingly, investors are cautioned not to place undue reliance on any forward-looking statements, which reflect management’s views as of the date hereof. Factors that may affect future results are disclosed under the headings “Risk Factors” and “Management’s Discussion and Analysis of Financial Condition and Results of Operations” in our filings with the Securities and Exchange Commission (the “SEC”), which are available at the SEC’s website at www.sec.gov. We undertake no obligation to publicly update any forward-looking statement, except as required by law, whether as a result of new information, future developments or otherwise.

GLOBAL WATER RESOURCES, INC.

CONSOLIDATED BALANCE SHEETS

As of March 31, 2016 and December 31, 2015

(Unaudited)

GLOBAL WATER RESOURCES, INC.

CONSOLIDATED STATEMENTS OF OPERATIONS

For the Three Months Ended March 31, 2016 and 2015

(Unaudited)

GLOBAL WATER RESOURCES, INC.

CONSOLIDATED STATEMENTS OF CASH FLOWS

For the Three Months Ended March 31, 2016 and 2015

(Unaudited)

GLOBAL WATER RESOURCES, INC.

CONSOLIDATED STATEMENTS OF OPERATIONS

For the Three Months Ended March 31, 2016 and 2015

(Unaudited)