Ier

{{other uses}}

{{Infobox river

| name = Ier

| native_name =

| native_name_lang =

| name_other = Ér

| name_etymology =

| image = Ér.jpg

| image_size =

| image_caption = The frozen river

| pushpin_map = Hungary#Romania

| subdivision_type1 = Countries

| subdivision_name1 = Romania and Hungary

| subdivision_type2 = Counties

| subdivision_name2 = {{hlist|Satu Mare|Bihor|Hajdú-Bihar}}

| subdivision_type3 = Villages

| subdivision_name3 = {{hlist|Andrid|Săcueni|Diosig|Pocsaj}}

| length =

| width_min =

| width_avg =

| width_max =

| depth_min =

| depth_avg =

| depth_max =

| discharge1_location=

| discharge1_min =

| discharge1_avg =

| discharge1_max =

| source1 =

| source1_location =

| source1_coordinates=

| source1_elevation =

| mouth = Barcău (Berettyó)

| mouth_location = Pocsaj

| mouth_coordinates = {{coord|47.2779|21.7997|display=inline,title}}

| mouth_elevation =

| progression = {{RBarcău}}

| river_system =

| basin_size =

| tributaries_left = Checheț

| tributaries_right = Salcia

| custom_label =

| custom_data =

| extra =

}}

The Ier or Eriu ({{langx|hu|Ér}}) is a right tributary of the river Barcău (Berettyó) in Romania and Hungary.{{GeoSource|RO|Annex7|220}}{{GeoSource|RO|Atlas|123-125|III.1.44.33.28}} It discharges into the Barcău in Pocsaj. The Andrid Dam is constructed on this river. The Ier flows through the villages Mihăieni, Eriu-Sâncrai, Ghirolt, Rădulești, Hotoan, Sudurău, Dindești, Andrid, Sălacea, Cherechiu, Săcueni, Diosig in Romania, and Pocsaj in Hungary. In Romania, its length is {{convert|100|km|abbr=on}} and its basin size is {{convert|1392|km2|abbr=on}}.{{GeoSource|RO|Atlas|123-125|III.1.44.33.28}}