Answer: I think the best approach is to terrace the yard to keep the lawn level above the wetland buffer. You'll be using fertilizers to keep your lawn green and if the slope is too great, a lot of nitrogen will be included in the runoff. Keeping the lawn separate and then planting native vegetation in the last few feet of the yard will help keep the fertilizers from running off and into the wetland area.
Best wishes with your new landscape.
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