From 8e4cb9a7fc2a88bea384837c7c3d2556994fe0d0 Mon Sep 17 00:00:00 2001
From: Joshua Larsen <jlarsen@usgs.gov>
Date: Thu, 5 May 2022 13:13:55 -0700
Subject: [PATCH 1/2] fix(ModflowUzf1): fix for loading negative iuzfopt

---
 autotest/t034_test.py   | 43 +++++++++++++++++++++++++++++++++++++++++
 flopy/modflow/mfuzf1.py |  4 ++--
 2 files changed, 45 insertions(+), 2 deletions(-)

diff --git a/autotest/t034_test.py b/autotest/t034_test.py
index 2b30612263..2bf3c59a84 100644
--- a/autotest/t034_test.py
+++ b/autotest/t034_test.py
@@ -622,6 +622,48 @@ def test_load_write_wel_option_line():
     assert wel.iunitramp == 20
 
 
+def test_uzf_negative_iuzfopt():
+    model_ws = f"{base_dir}_test_uzf_negative_iuzfopt"
+    test_setup = FlopyTestSetup(verbose=True, test_dirs=model_ws)
+
+    ml = flopy.modflow.Modflow(
+        version="mfnwt",
+        exe_name="mfnwt.exe",
+        model_ws=model_ws
+    )
+    dis = flopy.modflow.ModflowDis(
+        ml,
+        nper=2,
+        perlen=[1,1],
+        nstp=[1,1],
+        tsmult=1,
+        steady=[True, False]
+    )
+    bas = flopy.modflow.ModflowBas(ml)
+    upw = flopy.modflow.ModflowUpw(ml)
+    oc = flopy.modflow.ModflowOc(ml)
+
+    iuzfbnd = 1
+    irunbnd = 1
+    vks = 1e-4
+    surfk = 1e-4
+
+    finf = 1e-6
+    pet = 1e-8
+    extdp = 0.2
+    extwc = 0.10
+
+    uzf = flopy.modflow.ModflowUzf1(
+        ml,
+        nuztop=3,
+        iuzfopt=-1,
+        irunflg=1,
+        ietflg=1,
+        irunbnd=1,
+        specifysurfk=True,
+        seepsurfk=True
+    )
+
 if __name__ == "__main__":
     test_create_uzf()
     test_read_write_nwt_options()
@@ -632,3 +674,4 @@ def test_load_write_wel_option_line():
     test_load_write_wel_option_block()
     test_load_write_wel_option_line()
     test_uzf_surfk()
+    test_uzf_negative_iuzfopt()
diff --git a/flopy/modflow/mfuzf1.py b/flopy/modflow/mfuzf1.py
index 7f3b469a93..3e3ca31d70 100644
--- a/flopy/modflow/mfuzf1.py
+++ b/flopy/modflow/mfuzf1.py
@@ -1005,7 +1005,7 @@ def load_util2d(name, dtype, per=None):
             load_util2d("irunbnd", np.int32)
 
         # dataset 4
-        if iuzfopt in [0, 1]:
+        if np.abs(iuzfopt) in [0, 1]:
             load_util2d("vks", np.float32)
 
         # dataset 4b
@@ -1049,7 +1049,7 @@ def load_util2d(name, dtype, per=None):
             if nuzf1 >= 0:
                 load_util2d("finf", np.float32, per=per)
 
-            if ietflg > 0:
+            if ietflg > 0 and iuzfopt > 0:
                 # dataset 11
                 line = line_parse(f.readline())
                 nuzf2 = pop_item(line, int)

From 095b455a6a4402d3e54d1a8ec3176e5805b7f5c1 Mon Sep 17 00:00:00 2001
From: Joshua Larsen <jlarsen@usgs.gov>
Date: Thu, 5 May 2022 13:18:38 -0700
Subject: [PATCH 2/2] remove unused variables from test

---
 autotest/t034_test.py | 10 ----------
 1 file changed, 10 deletions(-)

diff --git a/autotest/t034_test.py b/autotest/t034_test.py
index 2bf3c59a84..cd32013b56 100644
--- a/autotest/t034_test.py
+++ b/autotest/t034_test.py
@@ -643,16 +643,6 @@ def test_uzf_negative_iuzfopt():
     upw = flopy.modflow.ModflowUpw(ml)
     oc = flopy.modflow.ModflowOc(ml)
 
-    iuzfbnd = 1
-    irunbnd = 1
-    vks = 1e-4
-    surfk = 1e-4
-
-    finf = 1e-6
-    pet = 1e-8
-    extdp = 0.2
-    extwc = 0.10
-
     uzf = flopy.modflow.ModflowUzf1(
         ml,
         nuztop=3,