Water Management net sales in the third quarter were flat with the prior year on a reported basis as 1% core growth was offset by a 1% adverse impact related to foreign currency translation. Resulting core net sales driven by market share gains and increased alternative market sales in our non-residential construction end-markets were partially offset by expected lower shipments to our North American municipal water end-markets.
Water Management Adjusted EBITDA in the third quarter was $24 million and Adjusted EBITDA as a percentage of sales increased 210 basis points to 14.0%.
Non-GAAP Financial Measures
The following non-GAAP financial measures are utilized by management in comparing our operating performance on a consistent basis. We believe that these financial measures are appropriate to enhance an overall understanding of our underlying operating performance trends compared to historical and prospective periods and our peers. Management also believes that these measures are useful to investors in their analysis of our results of operations and provide improved comparability between fiscal periods. Non-GAAP financial measures should not be considered in isolation from, or as a substitute for, financial information calculated in accordance with GAAP. Investors are encouraged to review the reconciliation of these non-GAAP measures to their most directly comparable GAAP financial measures. A reconciliation of non-GAAP financial measures presented above to our GAAP results has been provided in the financial tables included in this press release.
Core sales excludes the impact of acquisitions, divestitures and foreign currency translation. Management believes that core sales facilitates easier comparisons of our net sales performance with prior and future periods and to our peers. We exclude the effect of acquisitions because the nature, size and number of acquisitions can vary dramatically from period to period and between us and our peers, and can also obscure underlying business trends and make comparisons of long-term performance difficult. We exclude the effect of foreign currency translation from this measure because the volatility of currency translation is not under management's control.