--- a/pkg/imports/sec.go	Fri May 31 17:43:39 2019 +0200
+++ b/pkg/imports/sec.go	Fri May 31 20:06:27 2019 +0200
@@ -74,29 +74,22 @@
         relation = 'waterway.sections'::regclass)`
 
 	secInsertSQL = `
-WITH r AS (
-  SELECT isrsrange(
-    least(($1::char(2),
-           $2::char(3),
-           $3::char(5),
-           $4::char(5),
-           $5::int)::isrs,
-          ($6::char(2),
-           $7::char(3),
-           $8::char(5),
-           $9::char(5),
-           $10::int)::isrs),
-    greatest(($1::char(2),
-              $2::char(3),
-              $3::char(5),
-              $4::char(5),
-              $5::int)::isrs,
-             ($6::char(2),
-              $7::char(3),
-              $8::char(5),
-              $9::char(5),
-              $10::int)::isrs)
-    ) AS r),
+WITH
+bounds (b) AS (VALUES (
+    ($1::char(2),
+     $2::char(3),
+     $3::char(5),
+     $4::char(5),
+     $5::int)::isrs
+  ), (
+    ($6::char(2),
+     $7::char(3),
+     $8::char(5),
+     $9::char(5),
+     $10::int)::isrs)),
+r AS (SELECT isrsrange(
+    (SELECT b FROM bounds ORDER BY b USING <~ FETCH FIRST ROW ONLY),
+    (SELECT b FROM bounds ORDER BY b USING >~ FETCH FIRST ROW ONLY)) AS r),
 axs AS (
   SELECT ISRSrange_axis((SELECT r FROM r), $16::double precision) AS axs)
 INSERT INTO waterway.sections (