fix(well-inventory): preserve attempted water-level records when depth-to-water is blank

- Treat blank depth_to_water_ft values as missing instead of invalid numeric input
- Create water-level sample and observation records when water_level_date_time is present even if no depth value was obtained
- Preserve attempted measurements for dry, obstructed, or otherwise unreadable wells without dropping the observation record

Author: ksmuczynski

schemas/well_inventory.py

@@ -326,7 +326,7 @@ class WellInventoryRow(BaseModel):
         validation_alias=AliasChoices("mp_height", "mp_height_ft"),
     )
     level_status: Optional[str] = None
-    depth_to_water_ft: Optional[float] = None
+    depth_to_water_ft: OptionalFloat = None
     data_quality: DataQualityField = None
     water_level_notes: Optional[str] = None
 

services/well_inventory_csv.py

@@ -739,12 +739,7 @@ def _add_csv_row(session: Session, group: Group, model: WellInventoryRow, user)
     )
     session.add(fa)
 
-    if model.depth_to_water_ft is not None:
-        if model.measurement_date_time is None:
-            raise ValueError(
-                "water_level_date_time is required when depth_to_water_ft is provided"
-            )
-
+    if model.measurement_date_time is not None:
         # get groundwater level parameter
         parameter = (
             session.query(Parameter)
@@ -790,6 +785,7 @@ def _add_csv_row(session: Session, group: Group, model: WellInventoryRow, user)
             value=model.depth_to_water_ft,
             unit="ft",
             observation_datetime=model.measurement_date_time,
+            measuring_point_height=model.mp_height,
             nma_data_quality=(
                 model.data_quality.value
                 if hasattr(model.data_quality, "value")

tests/test_well_inventory.py

@@ -19,6 +19,8 @@
     Location,
     LocationThingAssociation,
     Thing,
+    Sample,
+    Observation,
     Contact,
     ThingContactAssociation,
     FieldEvent,
@@ -455,6 +457,43 @@ def test_well_inventory_db_contents():
                     assert participant.participant.name == file_content["field_staff_2"]
 
 
+def test_blank_depth_to_water_still_creates_water_level_records(tmp_path):
+    """Blank depth-to-water is treated as missing while preserving the attempted measurement."""
+    row = _minimal_valid_well_inventory_row()
+    row.update(
+        {
+            "water_level_date_time": "2025-02-15T10:30:00",
+            "depth_to_water_ft": "",
+            "sample_method": "Steel-tape measurement",
+            "data_quality": "Water level accurate to within two hundreths of a foot",
+            "water_level_notes": "Attempted measurement",
+            "mp_height_ft": 2.5,
+        }
+    )
+
+    file_path = tmp_path / "well-inventory-blank-depth.csv"
+    with file_path.open("w", encoding="utf-8", newline="") as f:
+        writer = csv.DictWriter(f, fieldnames=list(row.keys()))
+        writer.writeheader()
+        writer.writerow(row)
+
+    result = well_inventory_csv(file_path)
+    assert result.exit_code == 0, result.stderr
+
+    with session_ctx() as session:
+        samples = session.query(Sample).all()
+        observations = session.query(Observation).all()
+
+        assert len(samples) == 1
+        assert len(observations) == 1
+        assert samples[0].sample_date == datetime.fromisoformat("2025-02-15T10:30:00")
+        assert observations[0].observation_datetime == datetime.fromisoformat(
+            "2025-02-15T10:30:00"
+        )
+        assert observations[0].value is None
+        assert observations[0].measuring_point_height == 2.5
+
+
 # =============================================================================
 # Error Handling Tests - Cover API error paths
 # =============================================================================
@@ -1037,6 +1076,24 @@ def test_water_level_aliases_are_mapped(self):
             "2025-02-15T10:30:00"
         )
         assert model.mp_height == 2.5
+        assert model.depth_to_water_ft == 11.2
+        assert model.water_level_notes == "Initial reading"
+
+    def test_blank_depth_to_water_is_treated_as_none(self):
+        row = _minimal_valid_well_inventory_row()
+        row.update(
+            {
+                "water_level_date_time": "2025-02-15T10:30:00",
+                "depth_to_water_ft": "",
+            }
+        )
+
+        model = WellInventoryRow(**row)
+
+        assert model.measurement_date_time == datetime.fromisoformat(
+            "2025-02-15T10:30:00"
+        )
+        assert model.depth_to_water_ft is None
 
     def test_canonical_name_wins_when_alias_and_canonical_present(self):
         row = _minimal_valid_well_inventory_row()