In W. B. Yeats's poem, "The Lake Isle of Innisfree," what indications does the speaker give of his present environment?

The first line establishes that the speaker is not at Innisfree. In this line, he expresses his wish to go there: either in actuality or in his mind. Given his peaceful, idealistic description of Innisfree as a magical place that he would want to escape to, we might surmise that his current environment is quite different. If he longs so badly to escape to such a place, perhaps his current environment is bland, boring, oppressive in some way, or a place not conducive to peace and tranquility. 

In the last two lines, the speaker says where he is: 

While I stand on the roadway, or on the pavements grey, 

I hear it in the deep heart's core. 

The speaker is on pavement, which is hard and immovable. This contrasts with the peaceful, freely moving water that he hears (in his mind) as he contemplates his escape to Innisfree. The pavement also suggests he is in a city. This makes the contrast between his current environment and Innisfree all the more dramatic. In his descriptions of Innisfree, he notes the sights and sounds of the natural landscape. Given this contrast, maybe his desire is to escape the noise and the counterfeit (buildings) culture of the city. He wants to go to a quieter place, a place that glimmers naturally.