Please help me translate this sentence.

Hi everybody,

I would be very, VERY grateful if someone can help me out (and actually sooner rather than later would be better in this case, but beggars can't be choosers).  I'm doing a bit of translating work, and the following highlighted portion is bothering me, especially the part in blue.

现实中的城市显 然更为宏大，屹立于黄浦江畔东岸的这座大厦，填补了这处由泥沙淤积而成的土地上缺少高度的遗憾。 很久以来，只有从 东面大海上飞来的海鸥，和每 年迁徙的候鸟经过这里时，才能顺带看一眼底下的人群，和不断变化的城市。

I included the second sentence for context only.  Now here is my current translation:

The actual city is obviously much more massive.  It is a source of great regret that this land on the east bank of the Huangpu River that was once covered with precious silt sediment has been covered up by this large building. 

Now here is what is bothering me:

1. Am I right to break the original Chinese sentence into two sentences?  It seems to me that "现实中的城市显 然更为宏大" and "屹 立于黄浦江畔东岸的这座大厦，填补了这 处由泥沙淤积而成的土地上缺少高度的遗憾" are two separate ideas, but perhaps I just don't get the idea being expressed.
2. I'm having trouble wrapping my head around.  It seems to me that 缺少 does not modify 高度的遗憾 .  I think per the second sentence, 缺少 refers to a lack of sedimentary land.  Thus, I said "precious silt sediment".  Does this seem right?

Any input would be greatly appreciated.  And by the way, I know the English has to be cleaned up a bit.  I just want to get the meaning down first.