The crisis at Thames Water Ltd. has left the $60 billion market for UK water utility bonds deeply divided. A measure of the dispersion in spreads in the sector has surged over the past few weeks as investors try to separate companies they see as well run, with manageable debt loads, from those that face the most operational and balance sheet issues. The standard deviation almost tripled after reports of a possible temporary nationalization of Thames Water, before settling at around double typical levels, according to data compiled by Bloomberg.