Assertion: water vole's number | /r/HasProperty | blamed
Facets:
value: for weakening them
type: PURPOSE
Source sentences:
text: Even drought stricken farmers who in the past lamented the water rats' habit of mining their irrigation ditch walls, are coming to recognise how important the rodents are at keeping the numbers of freshwater crayfish, which also dig tunnels in the irrigation channel walls and are blamed for weakening them structurally, to a manageable level.