Colorado’s western slope water managers have doubled down on their position that they will oppose federal legislation creating a new regulated pool of water to boost the falling level of Lake Powell unless Colorado adopts a policy that the pool should be filled only on a voluntary basis. At a well-attended water meeting last week, Andy Mueller, the general manager of the Colorado River Water Conservation District, said that without a new state policy putting limits on how water can be stored in the big reservoir, “You will find that our district, the Southwest District and hopefully others will be, frankly, opposing the federal legislation.”