Objective Thinker

Denver, CO USA

Voicemail:  303.362.8425

www.geocities.com/gpdenp

Contact information available on website

My Desire: What I wanted to accomplish

Obtain a northern Arizona community, which two parties of a small village and surrounding Native American reservation parties, feedback on the proposed USDA Natural Resources Conservation Service (NRCS) Natural Resource Plan (NRP) Revised Work Plan Schedule, review their expectations on the final product, present latest hydrologic analysis results, and discuss engineering considerations.  The community parties were sponsors of the study.  I was to facilitate discussion on current planning status and latest concerns.  I was to collaborate with the local District Conservationist (DC) to arrange meeting time, meeting location, opening and closing statements.

Some kind of obstacle or restraint I faced

Expected sponsor disappointment on the very slow delivery of services.  I anticipated that they would be holding a grudge and could be demanding for answers.

What I did step-by-step

Analyzed possible engineering alternatives and computed magnitude order cost estimates with the aid of MathSoft Mathcad, Lotus 1-2-3 spreadsheets, and Microsoft Word computer software.

Results were presented in a document entitled (5) Formulating Alternatives--Engineering.  This document featured established objectives and goals that were categorized by resource and benefit land areas, applicable federal technical and/or financial assistance programs, and engineering treatments.  It also included an executive summary of engineering treatments, methods, and cost estimates.

Developed the Revised Work Plan Schedule that included justification statements and a Gannt chart complete with tasks, completed task duration, projected uncompleted task duration, and projected completion date.  This task was completed using Microsoft Word and Project Planning computer software.

The Revised Work Plan Schedule was presented to the community representatives on June 13, 1996.

Attended by eight people, including the DC and myself.

I distributed the Revised Work Plan Schedule.

Orally summarized the justification statements by expanding on activities that have caused delays in project planning.  The sponsors were receptive to the explanations.  There were very few, if any comments on the delay.

Facilitated project objectives and goals discussion.

Distributed selected sheets from the document entitled (5) Formulating Alternatives--Engineering.

Discussion.  After giving the audience some time to look over the objectives and goals, I orally read the first few objectives.  These few objectives were orally read in an attempt to engage discussion on the project scope.  On the whole, the sponsors were receptive to the objectives and goals.

Facilitated treatment alternative discussion.

Hydrology.  I talked about the existing community access road wash crossing culvert discharge capacity and its corresponding predicted storm frequency event.  This capacity and corresponding storm frequency event were presented in the context of NRCS twenty-five-foot drop grade stabilization structure design criteria at the outlet of the existing culvert.  The culvert is predicted to reach capacity during a thirty-three-year storm event (three percent chance in any given year).  The culvert is expected to transmit the principal twenty-five-year storm event discharge (four percent chance in any given year) without overtopping.  The principal discharge is used for structural integrity analyses.  The culvert crossing is predicted to overtop, however, during the capacity 100-year storm event (one percent chance in any given year).  That is, some of the discharge would pass over the crossing, which would cut off vehicular traffic.  The capacity discharge is used to size either the structure inlet to insure that it can pass the capacity discharge or an emergency spillway system away from the structure.  At this time, it appears that the grade stabilization structure itself would need to pass the capacity discharge without overtopping.  Consequently, if upstream structures are not installed to reduce design discharges at this site, the culvert may need to be replaced with either a larger culvert system or a bridge.

A village community resident and local judge reiterated his opinion that the existing culvert is not large enough to pass high discharge storm events.

Series of grade stabilization structures in wash in-between the community access road wash crossing and the downstream rock outcrop.  As I was going through the engineering treatment list and was talking about the possible rock outcrop grade stabilization structure treatment downstream of the road crossing, the village community resident and local judge questioned if a structure at this site can benefit the road crossing.  I said that it could benefit the road crossing over the long term if wash profile slope and soil characteristics are such that erosions in the reach are minimized.  Otherwise, a series of grade stabilization structures may be recommended in-between the rock outcrop and the community road crossing.  This treatment may be of greater interest if wash erosion in this reach is a high concern.  Otherwise, two grade stabilization structures may be sufficient, one at the community road crossing and the other at the adjacent wash headcut directly east and south of the rock outcrop.  If a series of grade stabilization structures are constructed starting at the rock outcrop and venturing upstream toward the road crossing, a structure at the adjacent wash headcut may not be needed as potential erosive discharges can be contained by a combined grade stabilization and diversion structure at the rock outcrop.

Integrity of the recently formed community access road wash culvert outlet grade stabilization structure.  Concerns were expressed that the newly formed non-reinforced concrete and boulder baffle grade stabilization structure at the community access road crossing needs to have outlet scour protection.  In addition, comments were made on the lack of structural integrity that is becoming apparent at the downstream end where new cracks are forming.  My engineering judgment was that the new structure is a temporary structure that needs to be replaced with a permanent structure once a new grade stabilization structure plan is finalized and approved.

Current likelihood of wash left bank erosion due to community access culvert turbulent ‘jet’ outflow impact.  Comments were made that the left wash bank, looking downstream, immediately downstream of the community access road crossing severely erodes during high discharge events.  That is, the high velocity water ‘jet’ discharge coming from the culvert outlet directly impacts the left bank.  The DC proposed that the grade stabilization structure at the road crossing be aligned such that high velocity water impacts on the left bank are minimized.  I presented his preference for replacing the existing ten- by ten-foot culvert with a wider conduit, whether it is additional culverts or a bridge, and installing a stilling area such that lower velocity discharges can be conveyed through a controlled hydraulic jump.  The principal discharge hydraulic jump can be designed to be controlled within the grade stabilization structure.  The capacity flow hydraulic jump, on the other hand, may or may not be controlled within the structure.  Taking the DC’s recommendation of aligning the structure to minimize potential wash bank erosion can make mitigation for this flow.

Concern of trees, brush, boulders, and debris clogging community access road wash crossing inlet if culverts are used.  Opinions were expressed that one or more culverts at the community access road wash crossing cannot effectively prevent debris from clogging at the crossing inlet.  They talked about how trees, brush, and boulders moving down the wash during high discharge events collect and clog the upstream face of the existing ten- by ten-foot culvert.  They also made reference to the fact that vehicle guardrails on both sides of the crossing were removed to minimize clogging.  I presented conceptual treatments of either having one or more wider box culverts (say ten- by twenty-foot culverts) or a bridge.  As far as debris is concerned, the bridge treatment is probably the best treatment.  The bridge, however, may be more costly than the culvert treatment.

The DC and I visited the local Natural Resource Conservation District representative.

Description of the result

Sponsor feedback was received.

The community representatives approved the revised schedule by signing their names to the Revised Work Plan Schedule document.  Later in the day, the local Natural Resource Conservation District representative also gave approval of the schedule.  This document was submitted to the State Conservationist for their concurrence.  It was also sent to the national NRCS office for their records.

Reviewed sponsor expectations on what the final product should consist of.  Presented latest hydrologic analysis results.  Discussed engineering considerations.

Any measure or quantities to prove my accomplishment

An eight-page trip report and technical specialist action plan complete with a map and three photographs (Microsoft Word document with imported graphics) were developed and distributed to nineteen NRCS technical specialists.  These specialists served on the Water Resources Planning, Engineering Design, Plant Materials, and Soil Survey teams.