Arroyo Simi

{{Use American English|date=February 2025}}

{{Infobox river

| name = Arroyo Simi

| image = Arroyo-Simi-Biking-Trail-seen-from-Frontier-Park-Simi-Valley.jpg

| image_alt =

| image_caption = Arroyo Simi seen from Frontier Park.

| source1_location = Corriganville Park, Simi Valley

| mouth_location = Merges with Arroyo Las Posas in Moorpark, discharges to the Pacific by Mugu Lagoon

| subdivision_type1 = Country

| subdivision_name1 = United States

|length_mi=19

| source1_elevation =

| mouth_elevation =

| discharge1_avg =

| basin_size =

| river_system = Calleguas Creek

| tributaries_left = Runkle Canyon- and Bus Canyon Creeks, and Erringer Drain

| tributaries_right = Aaamos Canyon-, Dry Canyon-, Tapo Canyon-, Las Llajas Canyon-, and White Oak Creeks, and North Simi Drain

}}

The Arroyo Simi (Spanish for "Small Stream of Simi", sometimes also referred to as Simi Creek) is a {{convert|19|adj=on|mi}} westwards-running creek, located in California, United States, running from the city of Simi Valley and crosses the valley from east to west, before entering the city of Moorpark.{{Cite web

|title=Our Arroyo Ecosystem

|url=http://www.moorparkca.gov/DocumentCenter/View/3954

|url-status=live

|archive-url=https://web.archive.org/web/20150623015401/http://www.moorparkca.gov/DocumentCenter/View/3954

|archive-date=2015-06-23

|access-date=2015-06-08}}{{Cite web |date=January 2015 |title=ARROYO LAS POSAS AND ARROYO SIMI ARUNDO REMOVAL FEASIBILITY AND WATER SAVINGS STUDY |url=http://www.calleguas.com/images/las-posas-basin/vcwsd_arundo_removal_study_final-20150129_.pdf |url-status=dead |archive-url=https://web.archive.org/web/20150725213246/http://www.calleguas.com/images/las-posas-basin/vcwsd_arundo_removal_study_final-20150129_.pdf |archive-date=2015-07-25 |access-date=2015-06-08}}{{Cite web |url=http://www.calleguas.com/images/las-posas-basin/vcwsd_arundo_removal_study_final-20150129_.pdf |title=(Page 1) |access-date=2015-06-08 |archive-url=https://web.archive.org/web/20150725213246/http://www.calleguas.com/images/las-posas-basin/vcwsd_arundo_removal_study_final-20150129_.pdf |archive-date=2015-07-25 |url-status=dead }}Appleton, Bill (2009). [https://books.google.com/books?id=d0S2usx-oUoC Santa Susana]. Arcadia Publishing. Page 27. {{ISBN|9781439638200}}.Schad, Jerry (2009). Afoot and Afield: Los Angeles County: A Comprehensive Hiking Guide. Wilderness Press. Page 253. {{ISBN|9780899974996}}. It originates at Corriganville Park by the Santa Susana Pass, travels for {{convert|12|mi}} through Simi Valley, leaves the city limits of Oak Park at the western end of Simi Valley, continues for seven miles in Moorpark where it merges with Arroyo Las Posas by Hitch Road.{{cite web |date= |title=RSRPD Arroyo Simi Greenway Update |url=http://www.rsrpd.org/park/newparkprojects/arroyosimigreenway/arroyosimigreenway.html |url-status=dead |archiveurl=https://web.archive.org/web/20150623020201/http://www.rsrpd.org/park/newparkprojects/arroyosimigreenway/arroyosimigreenway.html |archivedate=2015-06-23 |accessdate=2015-06-08 |publisher=Rsrpd.org}}{{Cite web |title=An Overview of Phase 1 and Phase 2 of the Arroyo Simi Greenway Project |url=http://www.rsrpd.org/park/newparkprojects/arroyosimigreenway/arroyosimi.pdf |archive-url=https://web.archive.org/web/20160123192620/http://www.rsrpd.org/park/newparkprojects/arroyosimigreenway/arroyosimi.pdf |archive-date=January 23, 2016 |access-date=2024-04-18 }} It is a tributary to the Calleguas Creek, which enters the Pacific Ocean by its estuary at Mugu Lagoon by Naval Air Station Point Mugu.[http://www.nwrc.usgs.gov/techrpt/85-7-15.pdf Technical description] nwrc.usgs.gov {{Webarchive|url=https://web.archive.org/web/20160304120408/http://www.nwrc.usgs.gov/techrpt/85-7-15.pdf |date=2016-03-04 }} Arroyo Simi drains an area of 343 square miles in southern Ventura County. In its natural state, it is an ephemeral creek, which is only seasonally filled during winter time and periods of heavy rain. Today it is for the most part a concrete lined water drain that flows year round. Tributaries to the Arroyo Simi include the Alamos, Sycamore, Dry, Tapo, Las Llajas, White Oak, Runkle, and Bus Canyon Creeks, as well as the Erringer Road and North Simi Drains.{{cite web|url=http://portal.countyofventura.org/portal/page/portal/PUBLIC_WORKS/Watershed_Protection_District/Programs_and_Projects/Integrated%20Watershed%20Protection%20Plan/Appendix%20H.pdf |title=Archived copy |accessdate=2015-06-08 |url-status=dead |archiveurl=https://web.archive.org/web/20150623004305/http://portal.countyofventura.org/portal/page/portal/PUBLIC_WORKS/Watershed_Protection_District/Programs_and_Projects/Integrated%20Watershed%20Protection%20Plan/Appendix%20H.pdf |archivedate=2015-06-23 }}

Arroyo Simi Greenway is an ongoing construction project by the City of Simi Valley to increase the recreational use of its river parkways. The project includes new paved hiking and biking trails along the Arroyo Simi, exhibit signs, sixteen new trail entries, and more.{{cite web |last=Simon |first=Melissa |url=http://www.simivalleyacorn.com/news/2015-04-10/Front_Page/Arroyo_greenway_makes_progress.html |title=Arroyo greenway makes progress | www.simivalleyacorn.com |publisher=Simi Valley Acorn |date=2015-04-10 |accessdate=2015-06-08 |archive-url=https://web.archive.org/web/20150726001152/http://www.simivalleyacorn.com/news/2015-04-10/Front_Page/Arroyo_greenway_makes_progress.html |archive-date=2015-07-26 |url-status=dead }}{{cite web|author=Rachel McGrath |url=http://www.vcstar.com/news/outdoors/arroyo-simi-greenway-taking-shape_24416969 |title=Arroyo Simi Greenway taking shape |publisher=VC-Star |date=2014-07-02 |accessdate=2015-06-08}} The area is administered as the Arroyo Simi Bike Path by the Rancho Simi Recreation and Park District (RSRPD).{{cite web|url=http://www.rsrpd.org/park/arroyosimibikepath/arroyosimibikepath.html |title=RSRPD Arroyo Simi Bike Path |publisher=Rsrpd.org |date= |accessdate=2015-06-08 |url-status=dead |archiveurl=https://web.archive.org/web/20150611202801/http://www.rsrpd.org/park/arroyosimibikepath/arroyosimibikepath.html |archivedate=2015-06-11 }} It is home to native flora,{{Cite web |url=http://www.calleguas.com/images/las-posas-basin/vcwsd_arundo_removal_study_final-20150129_.pdf |title=Archived copy |access-date=2015-06-08 |archive-url=https://web.archive.org/web/20150725213246/http://www.calleguas.com/images/las-posas-basin/vcwsd_arundo_removal_study_final-20150129_.pdf |archive-date=2015-07-25 |url-status=dead }} fish, and birds. It is home to fish species such as the brown bullhead, green sunfish, bluntnose minnow, and mosquitofish.[http://www.rsrpd.org/park/newparkprojects/arroyosimigreenway/arroyosimi.pdf (Page 30).] {{webarchive |url=https://web.archive.org/web/20160123192620/http://www.rsrpd.org/park/newparkprojects/arroyosimigreenway/arroyosimi.pdf |date=January 23, 2016 }} It is an important habitat for various species of freshwater-nesting birds in the Simi Valley. Some of the species include the great blue heron, white-faced ibis, black-crowned night heron, green heron, black-necked stilt, great egret, snowy egret, belted kingfisher, black phoebe, killdeer, common yellowthroat, greater yellowlegs, American coot, and mallard.[http://www.rsrpd.org/park/newparkprojects/arroyosimigreenway/arroyosimi.pdf (Pages 30–33).] {{webarchive |url=https://web.archive.org/web/20160123192620/http://www.rsrpd.org/park/newparkprojects/arroyosimigreenway/arroyosimi.pdf |date=January 23, 2016 }}