diff --git a/pyproject.toml b/pyproject.toml
index 4c98e7c..f081c9c 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "overflow-hydro"
-version = "0.3.4"
+version = "0.3.5"
 description = "High-performance Python library for hydrological terrain analysis with parallel, tiled algorithms"
 readme = "README.md"
 requires-python = ">=3.11"
@@ -46,7 +46,7 @@ dependencies = [
 
 [project.optional-dependencies]
 gdal = [
-    "gdal>=3.6.2",
+    "gdal>=3.7.0",
 ]
 dev = [
     "pytest>=8.0.2",
diff --git a/src/overflow/__init__.py b/src/overflow/__init__.py
index ae99b35..2d84ff2 100644
--- a/src/overflow/__init__.py
+++ b/src/overflow/__init__.py
@@ -34,7 +34,7 @@
 from overflow._util.raster import snap_drainage_points as _snap_drainage_points
 from overflow.codes import FlowDirection
 
-__version__ = "0.3.4"
+__version__ = "0.3.5"
 
 
 def breach(
diff --git a/src/overflow/_extract_streams/core/extract_streams.py b/src/overflow/_extract_streams/core/extract_streams.py
index 9e51391..b821abf 100644
--- a/src/overflow/_extract_streams/core/extract_streams.py
+++ b/src/overflow/_extract_streams/core/extract_streams.py
@@ -430,6 +430,8 @@ def _extract_streams_core(
     write_lines(lines_layer, lines)
 
     # Clean up
+    points_layer = None
+    lines_layer = None
     del output_ds
     fac_ds = None
     fdr_ds = None
diff --git a/src/overflow/_fill_depressions/tiled/fill_depressions_tiled.py b/src/overflow/_fill_depressions/tiled/fill_depressions_tiled.py
index f4ee83f..542cc4f 100644
--- a/src/overflow/_fill_depressions/tiled/fill_depressions_tiled.py
+++ b/src/overflow/_fill_depressions/tiled/fill_depressions_tiled.py
@@ -332,8 +332,11 @@ def handle_raise_tile_result(future):
     while not task_queue.empty():
         time.sleep(0.1)
 
+    labels_ds.Close()
+    output_ds.Close()
+    if output_ds is not dem_ds:
+        dem_ds.Close()
+
     # tear down
     if cleanup_working_dir:
         shutil.rmtree(working_dir)
-    output_ds = None
-    labels_ds = None
diff --git a/src/overflow/_resolve_flats/tiled/resolve_flats_tiled.py b/src/overflow/_resolve_flats/tiled/resolve_flats_tiled.py
index 4b759f8..9746918 100644
--- a/src/overflow/_resolve_flats/tiled/resolve_flats_tiled.py
+++ b/src/overflow/_resolve_flats/tiled/resolve_flats_tiled.py
@@ -186,10 +186,12 @@ def _resolve_flats_tiled(
         chunk_size,
         tracker.callback,
     )
+    labels_ds.Close()
+    flat_mask_ds.Close()
+    fixed_fdr_ds.Close()
+    if fixed_fdr_ds is not fdr_ds:
+        fdr_ds.Close()
+    dem_ds.Close()
+
     if cleanup_working_dir:
         shutil.rmtree(working_dir)
-    dem_ds = None
-    fdr_ds = None
-    fixed_fdr_ds = None
-    labels_ds = None
-    flat_mask_ds = None
diff --git a/tests/test_raster_util.py b/tests/test_raster_util.py
index 485ee85..095dfcc 100644
--- a/tests/test_raster_util.py
+++ b/tests/test_raster_util.py
@@ -6,10 +6,8 @@
 
 from overflow._util.raster import raster_chunker, read_raster_with_bounds_handling
 
-band_fixtures = ["square_raster_band", "tall_raster_band", "wide_raster_band"]
 
-
-@pytest.fixture(name="raster_band", params=band_fixtures, scope="module")
+@pytest.fixture(name="raster_band", scope="module")
 def fixture_raster_band(request):
     """Create a random raster band for testing. Parametrized to test all band sizes."""
     return request.getfixturevalue(request.param)