online_tr55_detention:   TR-55 detention basin storage volume calculator A detention basin in an urban area. Reference:  Natural Resources Conservation Service. (1986). TR-55 Urban Hydrology for Small Watersheds, Chapter 6: Storage Volume for Detention Basins. INPUT DATA: [Sample input file] Watershed (optional):   Units:    SI units (metric) U.S. Customary units (SI units) [U.S. units] Catchment area A (ha) [ac]:      Warning: Undefined variable $unitsystems in /var/www/html/ponce/onlinetr55detention.php on line 361 Warning: Undefined variable $areaunits in /var/www/html/ponce/onlinetr55detention.php on line 363 Storm depth P (mm) [in]:      Warning: Undefined variable $unitsystems in /var/www/html/ponce/onlinetr55detention.php on line 380 Warning: Undefined variable $rainfallunits in /var/www/html/ponce/onlinetr55detention.php on line 382 Storm type:    Type I / Type IA Type II / Type III Pre-development peak flow Qo (m3/s) [cfs]:      Warning: Undefined variable $unitsystems in /var/www/html/ponce/onlinetr55detention.php on line 412 Warning: Undefined variable $flowunits in /var/www/html/ponce/onlinetr55detention.php on line 414 Post-development peak flow Qi (m3/s) [cfs]:      Warning: Undefined variable $unitsystems in /var/www/html/ponce/onlinetr55detention.php on line 431 Warning: Undefined variable $flowunits in /var/www/html/ponce/onlinetr55detention.php on line 433 OUTPUT: Please enter input data and press  Calculate.   Your request was processed at  04:24:22 am on April 3rd, 2025   [ 250403  04:24:22 ]. Thank you for running online_tr55_detention.   [140429]