CREATE TABLE table_13342 ("Township" TEXT, "County" TEXT, "Pop.  ( 2010 ) " FLOAT, "Land  (  sqmi  ) " FLOAT, "Water  ( sqmi ) " FLOAT, "Latitude" FLOAT, "Longitude" FLOAT, "GEO ID" FLOAT, "ANSI code" FLOAT)

what is the average water sqmi with a population (2010) more than 47 in the Brenna Township with Longitude less than -97.171507
SELECT AVG("Water (sqmi)") FROM table_13342 WHERE "Pop. (2010)" > '47' AND "Township" = 'brenna' AND "Longitude" < '-97.171507'
SELECT AVG("Water (sqmi)") FROM "table_13342" WHERE "Longitude" < '-97.171507' AND "Pop. (2010)" > '47' AND "Township" = 'brenna'