Arroyo Seco Projects

There are four potential Arroyo Seco projects, which are subject to change based on the SCW feasibility study planned in fiscal year 2020/21. The initial concepts are as follows:

(1) The first will direct wet and dry weather drainage from Pasadena and South Pasadena areas north of Arroyo Park and San Pascual Stables to a constructed wetlands, and use the captured water for park irrigation. The project will make use of an existing dike that receives dry weather flows. A walking and biking trail will be incorporated around the wetlands. This includes improving the adjacent trail along the Arroyo Seco which will further enhance the trail network connecting Pasadena and South Pasadena.

(2) The second will direct wet and dry weather drainage from Pasadena and South Pasadena areas north of the 110 Freeway to an underground detention basin and use the captured water for park irrigation.

(3) The third will direct wet and dry weather drainage from South Pasadena areas east of the Arroyo Seco Golf Course and north of Mission Street to a constructed wetland and use the captured water for park irrigation. The project will make use of an existing pond in the public Arroyo Seco Golf Course that currently receives dry weather flows from an existing dike to the north. The proposed design will increase its capacity and allow it to capture wet weather flows.

(4) The fourth will direct wet and dry weather drainage from South Pasadena areas east of the Arroyo Seco Golf Course and Pasadena Ave to a constructed wetland. The project will make use of existing unused space within the public Arroyo Seco Golf Course’s driving range. The proposed design will allow it to capture dry weather and wet weather flows. The existing irrigation system and adjacent potential water storage projects could be used to supply water to the wetlands during the dry season. The wetlands could also be used as a water feature for the driving range. If water cannot be supplied to the project during the dry season, the constructed wetlands could be replaced with an extended detention basin.