The following project concepts were studied by the technical team in the design stage.

The goals of the Machado Lake Project are to: Implement actions to meet nutrient TMDL commitments; Improve visual aesthetics and ecosystem wildlife habitat; Increase flood control capacity and geomorphic stability; and Create additional recreational opportunities.

To meet these goals the project will include a number of inlake rehabilitation improvements, riparian habitat enhancements, and stormwater treatment best management practices (BMPs) in three sub-areas: Machado Lake and associated riparian woodland areas; the freshwater marsh; and parkland areas adjacent to Vermont Avenue and Anaheim Street.

These improvements will create long-term benefits and cause short-term disruption of the use of some parts of Machado Lake and Harbor Regional Park.

Existing Conditions

Machado Lake and Associated Riparian Woodland
  • Removal of bottom sediment high in nutrients from Machado Lake;
  • Fisheries and macrophyte management to control nutrient cycling and sustain a healty aquatic system;
  • Lake edge wetlands along the lake’s shore and near-shore areas with native plants to improve aesthetics, habitat values, and pollutant buffering and treatment processes;
  • Floating/hydroponic wetlands to provide lake shading to keep the temperature down, uptake nutrients, and provide roosting habitat and protective cover for fish;
  • Increased dispersion of flows from the Wilmington Drain and through the riparian woodland thereby taking further advantage of the natural treatment capacity for low-flow treatment;
  • Addition of supplemental water from a recycled water source to maintain lake levels during the dry periods;
  • Exotic removal and native vegetation enhancements in the riparian woodland;
  • Removal of select hardened drainage inlets, daylighting of storm drains, runoff treatment, and installation of trash capture devices;
  • Installation of a lake aeration system to increase dissolved oxygen levels in the lake;
  • Improve dam outlet to provide lake circulation and possible downstream sediment transport.

Freshwater Marsh
  • Installation of trash capture devices in storm drains that discharge to the marsh (photo at right);
  • Creation of a low flow channel to separate low lake flows from low storm water flows;
  • Construction of two sediment control basins (for further treatment of storm water discharges);
  • Enhancement and expansion of existing coastal valley freshwater marsh vegetation;
  • Enhancement of existing willow scrub habitat;
  • Construction of a pond to capture runoff for controlled release to downstream wetlands;
  • Habitat improvements including removal of non-native invasive plants, debris, and planting of appropriate native riparian species.

Strategic Parkland Areas
  • Installation of bioswales at strategic locations to capture surface flows from parking and parkland areas,
  • Modifications to trail system to improve visitor circulation and minimize lake edge erosion;
  • Repair of the Harbor Golf Course Maintenance Yard Wash Rack and Cover;
  • Installation of a "smart" irrigation system for water conservation and dry weather runoff reduction;
  • New signs (e.g. no dumping, educational signage with water quality message);
  • Dog litter bag stations;
  • Additional/improved trash receptacles

This project will enhance the beneficial uses of the Wilmington Drain by reducing water pollution in the inlet storm drains, as well as the water in the drain itself, through a multi-step approach including storm water screening and treatment, bank stabilization, biofilters or similar BMPs, native vegetation restoration, and will consider recreational opportunities. By preserving and restoring the stream corridor with native vegetation, not only will water quality be improved, but also native habitat and species will be protected.
Project components being considered include:
  • Trash netting systems upstream of Lomita Avenue and at the Wilmington Project 510 Drain. These proposed systems will be optimally sited and sized based on the results of hydrology /hydraulics analysis to ensure that flood control will not be impaired by the devices. The trash capture component will capture trash and debris before they reach the rehabilitated habitat areas.
  • Exotic, invasive and non-native landscaping will be removed and replaced with appropriate native species. Allowable native riparian vegetation may then work with the natural processes to strengthen stream banks, reduce erosion, and provide channel stability.
  • Channel recontouring and alignment to optimize flood control and habitat value.
  • Pedestrian trails, some of which would double as an access road for maintenance vehicles.
  • Dog litter bag stations.
  • Additional/improved trash receptacles.
If you have questions or comments, please call the outreach coordinator at (213) 978-0317. The project description, concepts and design are preliminary and subject to change.