10. REHABILITATION PROVISIONS

At December 31, 2018, the total undiscounted amount of future cash needs for rehabilitation was estimated to be $73.5 million. A discount rate assumption of 2% and an inflation rate assumption of 2% were used to value the rehabilitation provisions. The changes in the carrying amount of the rehabilitation provisions are as follows:



	For the Year Ended December 31, 2018			For the Year Ended December 31, 2017
Beginning balance	$	70,712		$	77,382
Accretion of rehabilitation provisions	691			1,245
Changes in estimates	138			(1,923		)
Cost of reclamation work performed	(5,316		)	(5,992		)
Balance at the end of the period	$	66,225		$	70,712

Current portion	$	7,665		$	6,566
Long term portion	58,560			64,146
Total	$	66,225		$	70,712

During the year ended December 31, 2018, the Company recorded an increase in estimate for Wassa of $1.0 million due to a revision in the timing of payments. At December 31, 2018, the rehabilitation provision for Wassa was $17.2 million (2017- $17.4 million). The Company expects the payments for reclamation to be incurred between 2019 and 2027.

During the year ended December 31, 2018, the Company recorded a decrease in estimate for Prestea of $0.8 million. The decrease is due to a $3.1 million reduction in expected reclamation costs relating to the refractory liability and a $2.3 million increase in the expected reclamation costs relating to the non-refractory operation. The reduction of $3.1 million was primarily a result of a reduction in water treatment liability from ongoing treatment and a negative water balance. The reduction was recorded as other income since the carrying value of the underlying refractory assets were $nil after suspension of its operation in 2015. At December 31, 2018, the rehabilitation provision for Prestea was $49.0 million (2017 - $53.3 million). The Company expects the payments for reclamation to be incurred between 2019 and 2028.