We are very excited as we enter 2013. Our existing businesses are performing consistent with our expectations. We expect to realize an increasing contribution in 2013 and into 2014 from a number of our organic projects, such as Walnut Hill, Natchez, Wink, Wyoming and Texas City. Our two largest growth projects announced to date, our SEKCO joint venture with Enterprise Products and our recently announced project around ExxonMobil's Baton Rouge refinery complex, will contribute in 2014 and accelerate into 2015. We believe we are well-positioned, given the current available capacity in our offshore oil pipelines, to benefit in the latter part of this decade from the dramatically increasing level of development activity in the deepwater Gulf of Mexico.
Last week, we completed an offering of $350 million of senior unsecured notes. The proceeds were used to pay down borrowings under our revolving credit facility and for general partnership purposes. Subsequently, we have approximately $800 million of availability under our revolving credit facility. This allows us to comfortably be able to complete all of our announced projects without having to issue equity. As a result, we believe we are very well positioned to continue to achieve our goals of delivering low double-digit growth in distributions while increasing our coverage ratio and maintaining a better than investment grade leverage ratio, all without ever losing sight of our absolute commitment to safe, reliable and responsible operations."
Available Cash before Reserves (a non-GAAP measure) increased to $50.5 million in the fourth quarter of 2012 as compared to $37.3 million for the same period in 2011. Available Cash before Reserves for the full year 2012 increased to $179.2 million over the previous year total of $138.2 million. The primary components impacting Available Cash before Reserves are Segment Margin, corporate general and administrative expenses (excluding non-cash charges), interest expense and maintenance capital expenditures. Variances from the fourth quarter and full year of 2011 in these components are explained as follows: