Douglas County is standing on the edge of a $165 million pothole, according to a report scheduled to go before commissioners Thursday.Officials will be pitching a means to pay to fill that pothole.The amount is the worth of the county's roads, its largest fixed asset.County engineers say that its roads are right on the edge of the pothole cliff, representing the point at which the cost of repairing roads begins to rapidly increase.According to a report going to county commissioners, maintaining county roads at their current condition will require $4.5 million a year. Right now the county is paying $450,000 …