その湖は

as for that lake

→ 其の
phrase Rare #21,296
as for that lake その means “that” and 湖 means “lake”; は marks the topic. Depending on context, it can also simply be translated as “that lake.”
JA: その湖は冬になると凍ります。
EN: That lake freezes in winter.

その湖はとても深い

That lake is very deep.

その湖はどれくらい深い知りません

I don't know how deep that lake is.

その湖はこの地点が深い

The lake is deep at this point.

その湖はに水を供給している

That lake supplies the city with water.

明らかに安全および衛生上の理由からその湖はフェンス囲まれた

The lake was fenced off, clearly for safety and sanitation reasons.

その湖はこの地点が一番深いんです

This is the deepest point in the lake.

その湖は大きくて美しい

That lake is large and beautiful.