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See King County's updated 2009 Surface Water Design Manual.

This page contains the software programs referenced in the Surface Water Design Manual, as well as other supporting files related to stormwater analysis and facility design. The KCRTS model is a required methodology under the 1998, 2005 and 2009 King County Surface Water Design Manual for sizing detention and infiltration flow control facilities.

PLEASE NOTE: The 2016 edition of the Surface Water Design Manual does NOT employ KCRTS for hydrologic modeling.  The software for use with the 2016 SWDM is the Western Washington Hydrology Model 2012 (WWHM2012, downloadable for free from Washington State Ecology’s website http://www.ecy.wa.gov/programs/wq/stormwater/wwhmtraining/index.html  ) or MGS Flood (MGS Engineering Consultants, Inc., http://mgsengr.com/index.html ).  See SWDM 2016 Chapter 3, Section 3.2 for more information regarding the approved models for the 2016 SWDM.

KCRTS is still required for projects vested under the 2009 SWDM, unless otherwise approved to use WWHM2012 or MGS Flood.

KCRTS Hydrologic Model Program:

King County Runoff Time Series (KCRTS) Version 6.0

The KCTRS program is bundled with KCBW in the Zip file that can be downloaded from the link below.

KCBW Backwater Program:

King County Backwater Software (KCBW) version 6.0

The KCBW program is bundled with KCRTS in the Zip file that can be downloaded from the link below.

This Zip File contains the files to run the WKCRTS and WKCBW software.  Extract the files to the root directory of your C:/ drive. 

WKCRTS and WKCBW software: WKCRTS and WKCBW Version 6.0.

King County Runoff Time Series Model Software - Online Documentation

Links to downloadable reference documents

King County Backwater Software documentation

Links to downloadable reference documents.
 

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2005 Surface Water Design Manual Application Maps:

Application of the Design Manual's targeted protection levels is determined from the following three application maps of King County. The maps are available here to view or download. To view the Adobe Acrobat maps you need Acrobat Reader, Version 3.0 or later, which is FREE. This format was chosen to allow the user to zoom in and out, pan the map in any direction, and print the map at the best resolution possible. Click the icon below if you need the Adobe Reader.

About Acrobat Reader

1998 Surface Water Design Manual Application Maps:

Application of the Design Manual's targeted protection levels is determined from the following three application maps of King County. The maps are available here to view or download. To view the Adobe Acrobat maps you need Acrobat Reader, Version 3.0 or later, which is FREE. This format was chosen to allow the user to zoom in and out, pan the map in any direction, and print the map at the best resolution possible. Click the icon below if you need the Adobe Reader.

Get Acrobat Reader

Pond volume calculation spreadsheet

This Excel spreadsheet can be used to estimate pond volumes for typical land cover conversions on till soils.
PONDVOL.XLS (25k)
(King County provides no warranty of any kind as to the accuracy of this spreadsheet on specific projects. All facility volumes should be verified using the KCRTS software.)

KCRTS FAQ

Please review the frequently asked questions and responses before contacting the Water and Land Resources Division for technical support.

For help with the KCRTS program, please call (206) 425-4785.

KCRTS/HSPF data files:

Sea-Tac full historical runoff files

For more information, view the Sea-Tac Read me file before downloading.

1ST-HIST.EXE (2,432k)
Self-extracting file containing the Sea-Tac full historical runoff files. The period of record is water-years 1949 through 1998. Requires KCRTS Version 3.04 or later (see above), and 3 MB of available RAM.

Landsburg full historical runoff files

For more information, view the Landsburg Read me file before downloading.

1LA-HIST.EXE (3,322k)
Self-extracting file containing the Landsburg full historical runoff files. The period of record is water-years 1949 through 1998. Requires KCRTS Version 3.04 or later (see above), and 3MBs of available RAM.

Sea-Tac historical precipitation

For more information, view the Sea-Tac Precipitation Read me file before downloading.

1ST-PPT.EXE (209k)
Self-extracting file containing the Sea-Tac historical precipitation record in WDM format. The period of record is water-years 1949 through 1998. Also includes Puyallup pan evaporation for the same period. This file requires HSPF Release 9 or later and/or ANNIE (see above).

Landsburg historical precipitation

For more information, view the Landsburg Precipitation Read me file before downloading.

1LA-PPT.EXE
Self-extracting file containing the Landsburg historical precipitation record in WDM format. The period of record is water-years 1949 through 1998. Also includes Puyallup pan evaporation for the same period. This file requires HSPF Release 9 or later and/or ANNIE (see above).

For questions about the stormwater website, please contact Blair Scott, Water Quality Planner, King County Stormwater Services Section.