CONSIDERATIONS AND SUGGESTED PROCEDURES FOR BOTTOMLAND REHABILITATION ACTIVITIES

Many stream corridors, especially in populated settings, have been altered in manners now considered objectionable, and much effort and money have been expended ineffectively to reverse the previously applied modifications (often abuses). Guidelines suggesting considerations and procedures to rehabilitate altered bottomlands are outlined here. Emphasis is on the acquisition of thorough, data-based knowledge of those fluvial-geomorphic processes that determine landforms and flow rates of water-deficient drainage basins as a pre-requisite to a rational project design. The purpose, therefore, is to discuss how observations of fluxes of matter and energy, landforms, vegetation, and the changes, both natural and human-induced, that have caused their modification, placed in a conceptual context, can lead to a successful rehabilitation project.

Steps for implementing a rehabilitation project include development of (1) an understanding of how and why changes imposed within a drainage system have affected hydrologic and geomorphic processes and thereby have modified bottomland habitat, (2) a rehabilitation plan that has public recognition, cooperator (or political) backing, is feasible relative to desired outcome and available resources, and is compatible with related projects of the drainage basin, (3) a clearly defined rehabilitation objective and a technical design for the project consistent with that objective, and (4) an outline of post-rehabilitation activities.

The technical design should be consistent with the rehabilitation objective and should address issues of flow and flow regulation, basin and channel characteristics, bottomland surfaces, channel gradient, and floods. Elements of implementation should include the development of a timetable, budget, and work plan that acknowledges previous work and available data. Regardless of basin size, data needs include various maps and imagery, and information on weather, hydrology, geomorphology, biota, and land and water use.